Export thread

Cordless electric enthusiast, new to forum.

#1

Mark Widmer

Mark Widmer

Just joined your fine forum, looks like us electric mower users are definitely in the minority here :tongue:

I've been using a Black and Decker CMM1000 cordless electric that my wife and I bought 5 years ago. The nearest service centers are over an hour away, so I have had to learn on my own to fix a few problems with it and other electric mowers that belong to friends.

Looking forward to posting, learning, and helping out where I can.

Mark


#2

twall

twall

Welcome to LMF, Mark!

That thing looks simmilar to a Neuton......how close are they?


#3

Mark Widmer

Mark Widmer

Thanks for the welcome twall!

Looks like mine is comparable to the Neuton CE6: 19" blade, rear-mounted bag, and rated for mowing 1/3 acre**. But my CMM1000 runs on 24 volts while the CE6 used 36 V. Also, the CE6 battery is easily removable (unlike mine), easy to swap in a 2nd battery for cutting larger lawns ... a newer Black and Decker model has the swappable battery as well.

**These manufacturers' acreage ratings must be under pretty ideal conditions. In practice I can't finish my yard on a single charge, and we have a 1/4 acre, not all of which is grass. Needs a 2 hour recharge halfway through mowing in order to finish up.


#4

twall

twall

I was intrigued by the neutron (I get Hanyman magazine, and see the ads all the time) for about an hour.:laughing:

Then, I found my Snapper - and the rest is history....

How's that bag for capacity? How many times do you have to empty it in a 1/4 acre? My JD bagger is pathetic - 4 dumps per mow - and I'd say it's about a quarter.......


#5

N

noma

Mark widmer


I'm not real impressed with black and decker string trimmer that are cordless i have the grass-hog 18 volt. Those batterys don't last long enuff to trim around 3 building and three trees , it takes two batterys to trim that little bit.Any one have any idea to make those battery's hold a charge longer?:frown:


#6

K

KennyV

Mark Widmer said:
Just joined your fine forum, looks like us electric mower users are definitely in the minority here :tongue:


Looking forward to posting, learning, and helping out where I can.

Mark
Click to expand...

Welcome to the forum Mark....
I am no longer a user ... but I am a past user & still a proponent of electric mowers ... I had a great pair of John Deere Electric 90's... wonderful electric rider mowers... good to see you here using electricity... :smile:KennyV


#7

jmurray01

jmurray01

Who needs electric when you have petroleum power! :laughing:

Seriously though, I have a Flymo/Electrolux Micro 330, and a Qualcast Mow 'N' Trim. Both electric, and I use them both from time to time.


#8

Mark Widmer

Mark Widmer

Hey, thanks for the additional welcomes, everybody :smile:
twall said:
How's that bag for capacity? How many times do you have to empty it in a 1/4 acre? My JD bagger is pathetic - 4 dumps per mow - and I'd say it's about a quarter.......
Click to expand...
Yeah, it doesn't hold much. But not a big deal for me, I usually go with mulching mode anyway. Except once in a while when I want some cut grass to "feed" my compost pile. The bag is nice for cutting up and compacting leaves in the fall too, but it sure fills up fast like you said.

noma said:
Mark widmer
I'm not real impressed with black and decker string trimmer that are cordless i have the grass-hog 18 volt. Those batterys don't last long enuff to trim around 3 building and three trees , it takes two batterys to trim that little bit.Any one have any idea to make those battery's hold a charge longer?:frown:
Click to expand...
The B&D cordless Grass Hog uses a NiCad battery. Better to get something with a lithium battery. Those batteries last longer, and it's my impression that manufacturers tend to make better chargers for their lithium tools than for ones that use NiCads, in terms of not overcharging the battery.

I'm pretty happy with my Worx cordless trimmer (model GT WG151.5), I can go 20 or 30 minutes on 1 charge. If I had it to do over I would get the slow-charge version instead of the fast 30-minute charger. I wonder (can't confirm it) if the fast charger might have ruined the original battery, which they replaced for free to their credit. Don't know if this is an exception to my "lithium chargers are made better" theory, it could have just been a defective battery too.

jmurray01 said:
Who needs electric when you have petroleum power! :laughing:

Seriously though, I have a Flymo/Electrolux Compact 3000+, and a Qualcast Mow 'N' Trim. Both electric, and I use them both from time to time.
Click to expand...
Hard to argue against having power. The less powerful electrics seem more sensitive to dull blades and wet or tall grass, you just have to be willing to accept the limits along with the advantages ... and learn to sharpen your own blades! (Or maybe I should be more careful around all the stones that line our yard :biggrin:)

Mark


#9

twall

twall

KennyV said:
I am no longer a user ... but I am a past user & still a proponent of electric mowers ... I had a great pair of John Deere Electric 90's... wonderful electric rider mowers... good to see you here using electricity... :smile:KennyV
Click to expand...

I looked those up - they look a lot like my RX75! Too bad they are so rare. :frown: I've never seen one, and had you not mentioned it, would've never known they existed.....


#10

K

KennyV

twall;23434 ... they look a lot like my RX75! ....[/QUOTE said:
I believe everything except the engine compartment is the same...
Too bad you are farrrr away ... I would give you them, I'm sure most pf the parts are the same as the gas version...
The Electric 90 uses a 36 volt constant speed motor that belt drives a 3 speed & reverse standard gear box transaxle, rear drive wheels are a 5 bolt hole but bolt to a 3 bolt hub. Clutch and brake peddles look the same, Steering wheel is a 3 spoke wheel.... :smile:KennyV
Click to expand...


#11

twall

twall

KennyV said:
I believe everything except the engine compartment is the same...
Too bad you are farrrr away ... I would give you them, I'm sure most pf the parts are the same as the gas version...
The Electric 90 uses a 36 volt constant speed motor that belt drives a 3 speed & reverse standard gear box transaxle, rear drive wheels are a 5 bolt hole but bolt to a 3 bolt hub. Clutch and brake peddles look the same, Steering wheel is a 3 spoke wheel.... :smile:KennyV
Click to expand...

Too bad indeed...:frown: Looking really closely at them, it is actually closer in design to my R72 - but with bodywork! They are cool indeed.

Says, from what I've found, that they were produced in the early 70's......how long were they made?


#12

K

KennyV

twall said:
they were produced in the early 70's......how long were they made?
Click to expand...

around 10 years... not exactly sure... :smile:KennyV


#13

P

Paul Schruben

dead CMM1000 cordless mower

My B&D CMM1000 won't start. The gauge goes full green but the motor does not spin. I think the batteries are good but do not know how to test them. I think they are about half way through their normal life. I doubt if they went dead all of a sudden. It ran fine last week.
If I disconnect and reconnect the battery, it starts once and runs feebly.
I have not had either recall done, do you think that has anything to do with it?
I would hate to have to buy a new mower now, I'm waiting for the Bosch Rotak LI to make it to the States.:smile:


#14

K

KennyV

Hello Paul & Welcome to the LMF.
Good to see 'Electric' mowers...
That has (2) 12 volt batteries for a total of 24 volts... you nay only have 1 charging, check the voltage with it running... :smile:KennyV


#15

Mark Widmer

Mark Widmer

The "full green" on the battery gauge -- needle on the F -- indicates both batteries are at 24V. Since the gauge is (supposed to be) connected to the motor, this indicates the motor is getting the full 24 V. However, worn-out batteries may not be able to supply the necessary 12A current, even if they charge up to 24 V.

Out of curiosity, just how many years old are (1) the batteries and (2) the mower?

A bad cable or connection between the main circuit board and motor could also explain the motor not turning even though the battery gauge reading is good. Using a voltmeter directly at the motor, with the mower on, would confirm or rule that out.

Paul, it would be good to confirm that all wires are connected. You might check the 6 wire connections on the main circuit board (the board that has the 3 cables screwed to it.) On the side opposite of where the 3 heavy cables are, there are 6 wires connected with a spade-and-lug type connections, arranged in a row along the bottom edge in the figure below. Feel around behind the circuit board with your fingers, and make sure that all 6 connectors are connected.

MowerCMM1000_5177.jpg


Also, make sure the 3 cables are screwed firmly to the circuit board.


#16

P

Paul Schruben

dead CMM1000 cordless mower

Mark,

Thanks for the photo and suggestions. I checked the 6 spade-and-lug connectors, they are all tight. And the heavier cables are tight. Nothing looks fried on the circuit boards.
When I turn the mower on, I measure 24v at the brushes. I have BB batteries, two years old, probably 100 hours, but still had plenty of capacity the last time the mower ran 2 weeks ago. The mower just turned 7 years old.
This time when I disconnected and reconnected the battery and tried to start it, the battery gauge still went full green, but no feeble running, not even once.
Does anyone know if Black & Decker will respond to my email or should I call them?
Thanks again for your help.

Paul~


#17

Mark Widmer

Mark Widmer

Hi Paul,

I would try calling first, I think it's best to talk to a real person if you can.

If the motor gets 24V and doesn't run at all, it's sounding like either a motor problem or the brushes are worn. Maybe check for continuity with an ohmmeter (across the brushes, through the motor) -- with mower OFF. You'll need to disconnect the brake wire first, since that provides a short across the motor and will mask an open circuit in the motor coils or bad brush contact. Just undo the spade-and-lug connection from either end of the brake wire.

Sounds like the battery is fine. They shouldn't fail so quickly, in just a couple of uses. And it sounds like your first battery lasted 5 years so you are not mistreating them.


#18

P

Paul Schruben

CMM1000 repair

Mark,

Thanks for suggesting worn brushes. The red side was worn to the point where it no longer contacted the commutator. Black and Decker has the brushes on backorder, so I made a copper shim to pad it out until the new brushes arrive.

I'm hoping my CMM1000 lasts until the lithium-battery mowers arrive in the States. The Gardena Powermax 42 A Li and Bosch Rotak 43 LI have 36v 4.5 AHr (162WHr) batteries. The Gardena is available now, the Bosch is currently shipping with a 94 WHr battery. For U.S. tastes, they need about 400 Whr, and 50 cm blades. I was hoping they had brushless induction motors but the Bosch motor says DC.


#19

Mark Widmer

Mark Widmer

Paul, that's good to know you can still get the brushes. Did you end up calling them, or was the communication online (email, or through website)? When I check the Black and Decker website, they say the brush/wire set is no longer available. I may want to order a set for myself now, in case they really do discontinue them.

I'm surprised the Li-ion models are only 160 W-hrs, that's not going to cut very much grass. I guess that's a design compromise, given the higher price of Li batteries. Perhaps that works over in Europe.


#20

P

Paul Schruben

CMM1000 repair

Mark,

The email reply from B&D was "take it to the service center." Not helpful. I was also disturbed to see the brushes no longer available in the online parts list. They even zeroed out the part number! But I noticed the CMM1200 motor, brush insert, brush spring, and brush cap, have identical part numbers, so the CMM1200 brushes should fit. I called B&D and asked if it was the same part, they did not know, but I ordered them anyway.

Today I'm noticing that the MM1800 brushes are available now, and cost less than half as much. The motor is different, but the insert, spring, and cap are identical. What is even more strange is that the newest models CM1836 and CM1936 have reverted to the old unavailable brushes. Maybe the parts lists are incorrect. At any rate, if I was ordering today I would probably order 2 of each because shipping costs $10.50.

model type motor brushes insert spring cap
cmm1000 242776-03 not avail 242274-00 242207-00 242253-01
cmm1200 1-2A 242776-03 241648-01 242274-00 242207-00 242253-01
cmm1200 3 90551054 241648-01 242274-00 242207-00 242253-01
mm1800 242480-02 242273-00 242274-00 242207-00 242253-01
cm1836 90548854 241648-01 242274-00 242207-00 240808-01
cm1936 90548259 241648-01 242274-00 242207-00 240808-01

241648-01 $6.04 backordered
Detail

242273-00 #$2.49 available now
Detail

Parts confusion is the pits. Not consumer-friendly. Brushes are a wear part, like brake pads. A business plan that zeros out part numbers as they age makes no sense. If they are trying to encourage us to buy a new mower, we will do so - but probably not a Black and Decker. That Honda-engined Toro is mighty tempting. Hopefully it will be a long time before the brushes disappear, but there is an analogy in the computer world, for instance, no more Apple OSX upgrades for machines over 5 years old.

Paul~


#21

Mark Widmer

Mark Widmer

Thanks for the part numbers. I see from the B&D site they're back-ordered until June 15. Hope you're willing to post how things work out, once you get them installed. Guess I'll hold off on ordering them for now -- just inspected mine, they have maybe 3/16" left until the spring is completely extended and will no longer push the brush up against the motor. I have now measured the length of the (-) terminal brush with my calipers, so I can monitor its rate of wear.

By the way, be careful with handling the (-) cable that runs between the motor, battery, and circuit board. There is a short length of skinny & stiff wire in that cable, susceptible to breaking if it is flexed back and forth too much. The skinny wire is located in the white insulated part of the cable. I had to repair mine a couple of years ago; here are more details on fixing it in case yours breaks too:


Scroll down the page until you get to "Fixing a broken wire".


#22

P

Paul Schruben

CMM1000 replacement brushes

Now Black and Decker says the CMM1000 brushes are backordered until 3/8/2012. Waiting 9 months for parts is not exactly consumer friendly. I'm ordering the MM1800 brushes. It only costs $16 to find out if they work.


#23

K

KennyV

Re: CMM1000 replacement brushes

Paul Schruben said:
I'm ordering the MM1800 brushes. It only costs $16 to find out if they work.
Click to expand...

Brushes are made from very soft material... You can re-size & re-shape them easily with a common file... get the basic configuration you need and form to fit... :smile:KennyV


#24

P

Paul Schruben

Abtec Parts sells the correct brushes.
Abtec Parts link

Fortunately I was able to cancel the MM1800 brushes order at B&D.


#25

Mark Widmer

Mark Widmer

Paul Schruben said:
Abtec Parts sells the correct brushes.
Abtec Parts link
Click to expand...
Awesome! I am going to order 2 sets.

Thanks Paul.


#26

P

Paul Schruben

Black and Decker CMM1000 lower handle broke

The lower handle on my Black and Decker CMM1000 broke, part number 52 in the diagram. It snapped where the main vertical bolt goes through it. You can see the bolt hole to the left of the number 4 in the diagram. This is a flimsy design, especially considering how heavy the mower is.

The part is on back order. That means it will never be back in stock. If anyone knows where I can obtain this part please let me know. Just for grins I ordered it from the two places that used to stock it, B&D and ToolPartsDirect.com. We'll have a race.

This part is difficult to fix, probably easier to make a new one. It might be time for a new mower.:frown:

Attachments





#27

Mark Widmer

Mark Widmer

Damn, Paul, you are having bad luck with that mower lately. Looks like a 2' or so piece of steel tubing might do the job, but the tricky part would be bending it into the right shape without collapsing the tube at the bend.


#28

P

Paul Schruben

Black and Decker CMM1000 lower handle broke

Black and Decker no longer says Backordered. Now it says In stock, limited quantities.
90564274 HANDLE, LOWER

ToolPartsDirect.com shows a new, less expensive part, $6.60 vs $9.67, but it is still not in stock. Same part number as B&D.
90564274 HANDLE, LOWER Replaces 242887-01

So I asked ToolPartsDirect to cancel my order.


#29

P

Paul Schruben

CMM1000 lower handle repair

I replaced the broken left lower handle. Simple repair.

But I had I ordered two lower handles, so I thought I might as well replace the right-side handle as well. BIG MISTAKE! This is a difficult repair. The right lower handle anchors the spring that lifts the mower for cutting height adjustment. With the spring attached at both ends, it is very difficult to muscle the handle in place. So I unhooked the front end of the spring where it attaches to the linkage. The handle slid easily into place. Then I made a long hook tool to stretch the spring and attach the front end to the linkage, but the spring is just too strong to stretch that far by hand. So to change cutting height now, I turn the mower on it's side to take the weight off. I'm guessing the factory has a tool that muscles the lower handle in place with the spring attached.

The lithium-battery mowers can't come soon enough.


#30

J

jnodak

Came across this website while researching brushes for our CMM1000. We have resurrected this mower at least 5 times and after 15 years of ownership, I'm not ready to give up on it. My husband fabricated a left side handle out of electrical conduit, but it did not hold up and eventually both sides of the handle broke. The current fix consists of rebar inserted into the handle tubes that span the breaks. These pieces were then brazed together to form a solid handle base. The handle is much sturdier than ever. Found out today that the CMM1000 has been recalled and if you send it to the service center, they will upgrade it to a CMM1200. Any idea what they all do? I have the phone number for the nearest service center, but am curious if anyone has had there mower upgraded and what all was done. It would be great if we could get a new motor out of it.


#31

P

Paul Schruben

The first recall replaces the circuit board to reduce the possibility of a fire during charging. Has your motor had problems other than worn brushes?

More troubling is the safety-key recall. I have not taken mine in yet for either recall, but I think I will call B&D next week.
Black & Decker Recalls Cordless Electric Lawnmowers Due to Laceration Hazard

Could you ask your husband how he installed the right lower handle? If I attach the spring first, it seems impossible to maneuver the handle into position. Thanks.


#32

Mark Widmer

Mark Widmer

jnodak said:
Found out today that the CMM1000 has been recalled and if you send it to the service center, they will upgrade it to a CMM1200. Any idea what they all do?
Click to expand...
I'm pretty sure they just send you a CMM1200. I doubt they actually modify your CMM1000, if that is what you are thinking.

If I ever did take my CMM1000 in for the upgrade to CMM1200, I would first remove the battery gauge so that I could install it on the CMM1200 (which doesn't have one).


#33

J

jnodak

Paul Schruben said:
Could you ask your husband how he installed the right lower handle? If I attach the spring first, it seems impossible to maneuver the handle into position. Thanks.
Click to expand...

Sorry for the delay in getting back to you, but we've been trying to remember if there was any trick to get it all hooked up. It's been several years since my husband fixed the handle. I asked him about it and he said that he remembers it was a challenge to get the spring attached, but that he had to muscle it to get it hooked up. He wasn't able to provide any details as to how he got it attached other than eat your Wheaties. Sorry we can't be more of a help. :frown:


#34

P

Paul Schruben

CMM1000 melted brush

Melted brush on CMM1000
I was trying to *scalp* an area of my lawn for reseeding, when the positive brush got too hot and melted the plastic parts around it. It could also be due to the much thinner lead on the new brush I installed recently. The negative side has the original brush and did not melt. Now I cannot remove the brush cap. The top motor housing is melted too. Does anyone know what is involved in replacing the top motor housing (aka end cap)?

What are the chances I need a new circuit breaker as well? It is no longer available. I might have to take it in for the recall and upgrade to CMM1200.

Paul~

Attachments







#35

T

tblanpied

Charger for CMM-1000

Hi,

I'm a big fan of the CMM-1000, and am really happy to see a forum that will help me take care of it for another bunch of years. We've had ours (type 5) since 2005, and I have to admit that it's been exactly zero trouble so far. We've cleaned it and sharpened the blade, but otherwise have had no issues to deal with at all. Part of it might be that we have a pretty small lawn (~1/8 acre), but it will mow/mulch that at least 5 times over before even recharging the battery, even after over 6 years now.

The problem right now is that we've actually lost our wall charger/transformer (long story!). I see that B&D/Dewalt no longer make them for this mower series (which is a bit bogus if you ask me, but par for the course in other industries, I guess). Can anyone help me figure out what specifications I should look for in finding a replacement wall charger unit? (or just flat out point me to one?) I can fashion a connector to fit the mower handily if it's not an original, but don't know exactly what to look for.

Alternatively, if I could find one from the CMM-1200, could I use that?

And yes, it's because we lost the charger that we know how many times we can mow the lawn before the battery discharges (!). Normally, it's plugged in 24/7 all year. We're not looking forward to running it down all the way--I'm sure that will shorten its life drastically.

Thanks.
Tom


#36

P

Paul Schruben

Re: CMM1000 melted brush

Fixing the melted brushes cost $110 at a local shop. It is probably not a good idea to use the new brushes with thinner leads in the old CMM1000 mower (see attached photo). First perform the free recall upgrade to the CMM1200, which likely has better voltage regulation.

Attachments





#37

Mark Widmer

Mark Widmer

Re: CMM1000 melted brush

Paul Schruben said:
It is probably not a good idea to use the new brushes with thinner leads in the old CMM1000 mower (see attached photo). First perform the free recall upgrade to the CMM1200, which likely has better voltage regulation.
Click to expand...
Paul, thanks for the heads-up on the brush leads. Does the "free upgrade" mean (as I think) they replace the old CMM1000 with a brand new CMM1200?


#38

Mark Widmer

Mark Widmer

Re: Charger for CMM-1000

FYI, I had replied to Tom via email back when he asked this question, but I might as well post the info here as well.

tblanpied said:
Hi,

I'm a big fan of the CMM-1000, and am really happy to see a forum that will help me take care of it for another bunch of years. We've had ours (type 5) since 2005, and I have to admit that it's been exactly zero trouble so far. We've cleaned it and sharpened the blade, but otherwise have had no issues to deal with at all. Part of it might be that we have a pretty small lawn (~1/8 acre), but it will mow/mulch that at least 5 times over before even recharging the battery, even after over 6 years now.

The problem right now is that we've actually lost our wall charger/transformer (long story!). I see that B&D/Dewalt no longer make them for this mower series (which is a bit bogus if you ask me, but par for the course in other industries, I guess). Can anyone help me figure out what specifications I should look for in finding a replacement wall charger unit? (or just flat out point me to one?) I can fashion a connector to fit the mower handily if it's not an original, but don't know exactly what to look for.

Alternatively, if I could find one from the CMM-1200, could I use that?

And yes, it's because we lost the charger that we know how many times we can mow the lawn before the battery discharges (!). Normally, it's plugged in 24/7 all year. We're not looking forward to running it down all the way--I'm sure that will shorten its life drastically.

Thanks.
Tom
Click to expand...

And my reply:
Hi Tom,

I just checked my CMM1000 charger, it says 26 V AC, 1 A for the output. So as long as you find a 26 VAC (not DC), and at least 1 Amp, it should work. It's likely that slightly less than 26V would work too, though it may take longer to charge the battery.

I'm not sure what the specs are for the CMM1200 charger, so I can't say whether it would work on the CMM1000. There is some circuitry inside the mower, in between where the charger plugs in and the battery. If that circuit is different for the 2 models, the charger specs could be different as well.

Good luck,

Mark
Click to expand...


#39

P

Paul Schruben

CMM1000 melted brush

Mark Widmer said:
Paul, thanks for the heads-up on the brush leads. Does the "free upgrade" mean (as I think) they replace the old CMM1000 with a brand new CMM1200?
Click to expand...

Mark and Tom,

I was not given the option of a new mower, just an upgrade kit. They replaced the black mower cover (upper shroud) and upper handle, including the switch and cordset. The switch now contains all of the circuitry - only a circuit breaker resides under the cover in a CMM1200, which is a simple plastic shell.

They also replaced the charger. It says 30V DC 1.2A. I still have my old charger but am reluctant to send it to you, Tom. The recall was due to houses burning down and laceration injuries. I recommend that you perform the free recall instead of replacing your charger.

I did not ask for the old parts back, so they kept the charge meter. I asked if they could re-install it. They said no because the entire cover is replaced. I do not see any physical reason why you cannot use the old cover with the new parts. Of course the connections would be your improvisation.

I can live without the meter - the sound is a good indicator of charge. Besides, the meter was only accurate if the load was identical. In other words, the meter dropping off to the yellow and red could be due to thicker, wetter grass or lower charge. It gave a higher reading when I re-mowed. BTW, I wonder how much more current is required to do a good job in one pass?

Paul~


#40

wjjones

wjjones

Welcome to the Forum!...


#41

Mark Widmer

Mark Widmer

wjjones said:
Welcome to the Forum!...
Click to expand...
Welcome to you too, from one joined-in-May-2011 member to another :biggrin:


#42

P

Paul Schruben

replacement batteries for the B&D CMM1200

I find that the OEM battery by B.B. Battery, model BP17-12, has the longest run time as it ages, and twice the service life as the other brands I've tried - UB12180 and Gruber Power.

For my next battery I considered a Shorai lithium motorcycle battery. The 18 Ah equivalent LFX18A1-BS12 weighs 2.12 lbs, versus 13.56 lbs for each of the CMM1200 lead batteries. Too bad they cost three times as much at $190 each. I asked Shorai which model they recommended for the B&D mowers. They said they cannot supply a battery for that application. I'm guessing the motorcycle batteries might have problems with the discharge rate, or the deep cycling, or the charger.

Black and Decker makes Li-battery powered trimmers, chain saws, leaf blowers, etc, but so far no mowers. I think lithium battery costs are still too high for the mowers to reach mass-market sales numbers. For instance, the Bosch Rotak 43 LI mower is available in the States this year for $500 from fruugo.us, but with a feeble 36 V, 2.6 Ah battery. That works out to 94 Wh, compared to the CMM1200 battery packs at 408 Wh. Spare 2.6 Ah Bosch batteries cost a whopping $300! The Bosch 36 V 4.5 Ah mower batteries are not available yet AFAIK.

Paul~


#43

F

floating ground

I've got a B&D CMM1000/1200 mule (a CMM1000 recalled and given a new upper deck).

Paul, have you looked at LiFeMnPO4 batteries from GBS? They're for sale at electricmotorsport.com. I too am thinking of replacing my 3rd set of dying lead acid batteries with Lithium ones. These GBS batteries are designed for traction, while the Shorai seem to be designed for starting gas engines. And the GBS batteries are cheaper. I'm this close ->.<- to buying a pair, but when you include cell balancers and shipping, its a $350 investment . . . and no one I can find has done this before. Is the charge circuitry built into the mower going to play well with the GBS cells? I don't know.

There IS a fellow over on the mynissanleaf.com forums who has put a different brand of lithium batteries (Thundersky?) in his electric mower, but he's got custom battery management circuitry, software, etc. More than I want to get into.

Phil
Houston, TX

PS: Much thanks to Mark Widmer for his electric mower blog. I was googling for info and his site came up, and on his site he talked up this forum. So I joined LMF!:smile:


#44

Mark Widmer

Mark Widmer

floating ground said:
Mark, I have a Black & Decker CMM1200 mower. Now, frankly, the only reason I joined this forum was because I wanted to replace the Lead Acid batteries in it with Lithium Iron Phosphate (LiFePO4) batteries and I was hoping there would be some discussion along that line here. Not because I'm a lawn mower enthusiast (I'm more of a lithium enthusiast). So, after posting in your New Members thread and not getting any response from anyone, I just went ahead and replaced them anyway. My photo-diary of the surgery can be found here: Black_n_Decker_CMM1200_gets_Li_batteries pictures by floating_ground - Photobucket

The new batteries weren't cheap, but they will have more stamina, last longer, and they weigh less which makes mowing a more pleasant experience. If anyone wants more details, please let me know.

Cheers to all,
Phil in Houston
Click to expand...
Hi Phil, and hello again Paul! This thread appears to be the de-facto Black & Decker forum here, so I am replying to the above post here. I have been pretty incommunicado over the winter, but Phil's project in getting lithium ion batteries for the CMM1200 have resparked my interest.

One question I have is, what does one do for a charger for the LI-ion batteries? Did a charger come with them? I would be leary of using the mower charger designed for sealed lead acid on Li-ion.

Mark

p.s. one reason I'm less active lately, other than it being off-season, is that I started a new job back in December.


#45

F

floating ground

Mark Widmer said:
Hi Phil, and hello again Paul! This thread appears to be the de-facto Black & Decker forum here, so I am replying to the above post here. I have been pretty incommunicado over the winter, but Phil's project in getting lithium ion batteries for the CMM1200 have resparked my interest.

One question I have is, what does one do for a charger for the LI-ion batteries? Did a charger come with them? I would be leary of using the mower charger designed for sealed lead acid on Li-ion.

Mark

p.s. one reason I'm less active lately, other than it being off-season, is that I started a new job back in December.
Click to expand...

Hi Mark,

Welcome back! 'Round these parts, mowing season is about 11 months long :smile:

All I bought were batteries and cell balancers. I emailed the battery seller about the charging issue, and he seemed to think the built-in charger on the mower would work okay. The batteries arrived well (probably fully) charged. After installing them, I did a quick 3 minute test mow then plugged the brick power supply into the mower, and the brick's green LED, indicating full charge, came on immediately. My first impression is the stock brick and charging circuit may never recharge the LiFePO4 batteries to 100%, but that will actually be better for long term life of the batteries. Time will tell!

Hope your new job's a good one.

Phil


#46

Mark Widmer

Mark Widmer

I'd be interested to hear back after a couple mowings and recharge cycles on how it's working out. Are these the 20 Amp-hr ones I saw at electricmotorsport.com?

Hey, you wrote you're a lithium enthusiast. So I'll just mention that I have a lithium-ion powered string trimmer from Worx that I really like -- this will be my third season using it.


#47

R

rscamp

Hello everyone. First post. Long time e-power user here - just not for lawn mowers - yet!

I just ran across this thread searching for information on modifying the batteries on cordless electric lawn mowers. There isn't much information out there - at least not specific to modding a newer cordless mower.

I dabble with e-power as a hobby (electric model aircraft and ebikes) and don't like noisy mowers. So a cordless mower seems like a logical choice. The lead-acid powered mowers are heavy and duration is poor. Gotta fix that...

I just ordered and received a B&D RB-3610 replacement battery assembly to see how easy it would be to replace the batteries in it. This fits the B&D CM/SPCM-1936 models. It is roomy inside so it looks like it will be pretty easy. So I'll proceed and get an actual mower. :)

In approximate terms, the initial evaluation shows that with LiPos, the battery capacity can be doubled while halving the battery weight. By the time all miscellaneous components, taxes and shipping are paid, this will cost around $400. That's not cheap, but then you've got a cordless mower that can be charged in an hour that should be able to mow a large yard (or perhaps an average yard a couple of times). And the OEM battery that comes with the mower is also available for use.

The nominal voltage will also be a bit higher but more importantly, the voltage under load will be considerably higher given the extremely low internal resistance of the LiPos. This should translate into less bogging in thicker grass.

I would consider some sort of "watt-meter" mandatory on something like this. I'll throw on an old Astro Wattmeter on it. This will report voltage, amps, power and capacity (Ah). I would attach it to the top of the battery enclosure so it can be viewed in use.

Anywho, I'll start ordering the materials this weekend. It could be a month before I have this done as I'll have to wait for the batteries to ship on a slow boat from China. :)

More details to follow...

Rob


#48

R

rscamp

Opening up the battery case is simple. Remove some Torx screws and lift off the top. A large empty space is left after the batteries and wiring harnesses are removed.

Attachments







#49

R

rscamp

The batteries are VRLA (valve-regulated lead acid) BB BP10-12 which are nominally 12V and 10Ah capacity for a gentle and unrealistic-in-this-application 20hr discharge. As these batteries are discharged in an hour or less in this application, the 1hr rated capacity of 6Ah is more realistic. This loss of capacity with discharge rate is known as the peukert effect. And since the discharge rate can be even higher than this and lead acid doesn't retain capacity well when deep cycled, this could be further derated to 4Ah or less.

The only reason to use lead acid batteries in this application is to reduce the initial cost. Users pay for this later by living with heavy and inefficient batteries that have a short cycle life.

Attachments







#50

R

rscamp

The main power connector is an Anderson Powerpole SBS50. Main wires are 14AWG and charge wires are 18AWG. Charge connectors are PP15 Powerpoles. All wire/connector connections are crimped.

Battery connections are 1/4" fastons. These are poor connections for high currents. These produce relatively high resistance connections that can become much higher resistance after a period of time.

Attachments





#51

R

rscamp

I really should have started a new thread for this. :smile:

Anywho, the proposed replacement batteries are eight of these. HobbyKing R/C Hobby Store : Turnigy 5000mAh 5S 20C Lipo Pack .

These would be used in a 10s4p (ten in series, 4 in parallel) arrangement to provide a maximum of 20Ah of capacity at nominally 38V. There is a derating with these also. To maximize cycle life, they will only be charged to 90% of capacity (90% SOC) and will have at least 10% left (90% DOD) giving this a nominal capacity of 16Ah.

This capacity is further derated by discharge rate but in this case, the discharge rate is so low relative to the current these batteries can comfortably deliver (easiliy > 100A!) that this is irrelevant. But let's say the capacity is only 14Ah to be conservative. This is much better than twice the 4-6Ah of the OEM battery - and with a savings of more than 10 pounds (5kg)!


#52

R

rscamp

Time for the obligatory warning regarding use of LiPo (Lithium Polymer) batteries. Relative to other battery chemistries they have excellent energy density and power density. Lithium Iron Phosphate and Lithium Manganese are also good choices and are more forgiving but don't match the performance of LiPos. However, LiPos present a risk of fire due to their volatility and need to be used within strict voltage limits to avoid damage.

High current LiPos like these must never be discharged to the point that they have a rest voltage below about 3.75V. The result will be reduced capacity or immediate failure. They must also never be charged above about 4.2V. The result will be reduced capacity or much worse. Fire is very unlikely but the consequences are dire - charging is best done in a place where no serious damage will occur if one of the batteries decides to become a flare.

LiPos can deliver so much current that shorting the wires can be catastrophic.

LiPos are not inherently self-balancing. Some means of maintaining voltage balance between parallel cell groups must be employed. On board real-time battery management is not necessary - a suitable regimen can be just checking balance on charge every few cycles.

So LiPos are great but you must know how to handle them. If you aren't comfortable with the above warnings and the maintenance and use requirements, don't use them.


#53

R

rscamp

Okay, so things have progressed a little faster than I anticipated. Home Depot had one of these environmental rebate programs on for replacing old gas mowers with push and electric mowers. The program was ending soon so we took in an old mower to get $100 off the 19" self-propelled model.

The battery was fully charged so I tried it out shortly after getting home. No surprises after reading the various reviews. I managed to get the front and back lawn done with it. The grass wasn't long, but it was fairly wet. Cut height will also have a huge impact on run time. I'll know better when I put a power meter on it.

I've got it on charge now with a computer charger so soon I'll know how much capacity was used (within reason). Charge rate is set at C/10 (1A for these 10Ah batteries) with a standard Pb CC-CV charge cycle. Charging is through the main power connector - I used the connector from the 'spare' battery pack to make the charge connector. I didn't use the small green and white Anderson charge connectors as they have what appears to be reverse-polarity protection diodes in the harness which may affect the voltage seen by the smart charger.


#54

R

rscamp

Capacity in on recharge was 3.56Ah. Based on the previous analysis, I don't think it would have run much longer.


#55

F

floating ground

Wow Rob, it sounds like you know what you're doing! Glad to see someone knowledgeable experimenting with this. I'm like the guy who knows enough to be dangerous :smile: Please do keep us informed of your progress.

Phil


#56

R

rscamp

floating ground said:
Wow Rob, it sounds like you know what you're doing! Glad to see someone knowledgeable experimenting with this. I'm like the guy who knows enough to be dangerous :smile: Please do keep us informed of your progress.

Phil
Click to expand...

Well Phil, I don't know much about electric lawn mowers!

I tip my hat to you for the improvements you have made to your mower. Electric power in general is excellent and can outperform IC engines in every meaningful way except for one thing - the batteries suck. What we can do here is make the batteries suck a lot less.

In fact, we can improve the batteries so much with these mods that the motor won't be up to the task. By that I mean with the right battery replacement we can have 3 or more times the energy and 3 or more times the electrical power capability compared to the OEM batteries but the motor is still a relatively low power brushed commutator motor designed for the original crappy OEM battery. In heavy grass that the batteries can now handle easily, the motor may repeatedly go into thermal shutdown.

Even though batteries have a long way to go there is NO REASON an electric mower TODAY can't be as powerful or more powerful than the IC engine equivalent. NONE! :) I think manufacturers need to make a quality product with good batteries and a good brushless outrunner motor/controller. Sure it will cost more but it will have a wider usable power range and open a few eyes...


#57

R

rscamp

Batteries arrived! I should be able to try them out this weekend...


#58

R

rscamp

Here are the 8 X 5s 5000mAh LiPo batteries fitted in the battery case with all wiring harnesses connected for power and balancing. A block of foam separates the batteries at the front and keeps them in place. Some double sided tape was used to make the batteries more secure. The battery wiring at the top will be compressed a bit by the top cover to further secure the batteries in place.

Attachments





#59

R

rscamp

Here's a close up of the parallel balancer adapter that joins the balance leads from the 4 parallel batteries in each series group. This was fashioned from some project board cut to size with mating PC mount connectors purchased at DigiKey. The common set of leads run through 20AWG wire to AMP Microfit connectors. I had already standardized on these for balance connections to the batteries I use for ebikes.

Attachments





#60

R

rscamp

Here's the finished battery. The power leads running to the "Whattmeter" exit through slots cut in the top cover. This matches how slots are already cut inside the top cover for routing the wires. Balance leads exit through grommetted holes in a similar manner. It isn't necessary to open the enclosure for normal charging/balancing activity with all these connections brought to the outside.

The charging connection is made by disconnecting the input to the Whattmeter and connecting the charger to the plug going to the batteries. Disconnecting the Whattmeter also resets it for the next use. Any meter can be used or the leads can be connected without a meter in place.

It will be interesting to see the actual voltage/current/capacity/power used under different conditions. I was going to put the meter on top but angling it like this makes it much easier to read in use.

I'll mow the lawn this afternoon and see how it works!

Attachments





#61

R

rscamp

Here's the mower just before starting the first mow with the Lithium Polymer battery.

Here's some data from the Whattmeter.

Initial rest voltage was 40.3V.

Running the self-propel drive alone without load consumed a surprisingly high 2.5A / 107W. High speed self-propel drive alone uphill consumed more than double this at 250W.

Running the main cutting motor alone consumed 7.2A / 293W.

All cutting was done at height setting 4 (lowest recommended for mulching) except as noted. This isn't particularly short. After cutting the front lawn, 2.485Ah was consumed and the rest voltage was 39.3V. Average power consumption ranged between 400 - 600W when cutting. Maximum power observed in some thick grass was around 900W.

At this point I threw in the freshly charged Pb battery that came with the mower and the speed was a bit slower going by the sound. So even after mowing a fair bit the lithium pack has higher voltage. I can't say I noticed a lot of difference in the amount the motor slowed down between the two packs suggesting the motor/wiring is limiting. Of course when the original Pb battery would be dying the LiPos are less than half done.

I stopped again at 5.036Ah consumed and the rest voltage was 38.8V. All parallel cell groups were in near perfect balance ranging between 3.80V and 3.81V.

Attachments





#62

R

rscamp

Here's the mower after mowing the entire lawn once and the back yard a second time at a height setting of 2 which is fairly low. The original Pb battery is in the foreground.

The closeup of the Whattmeter and a balancer shows the rest voltage was 38.1V, the capacity consumed was 9.834Ah (which is less than half of the absolute maximum capacity) and near perfect balance of cell groups.

In short, with these new batteries, there is NO RANGE ANXIETY. :) Range is now similar to a full tank on the gas mower!

The mower is a pleasure to use as it loses about 10 pounds (5kg) with the battery conversion. It is now significantly lighter and more maneuverable than the old gas mower.

Not everything is as good as it could be, however. Although the mower is a bit stronger with the LiPos, the motor is still a limiting factor in its power. Once electrical power consumption exceeds about one horsepower (750W), the motor begins to struggle. The batteries hold a high voltage so they are not the issue. The switch to LiPos would be perfect if combined with a stronger motor.

Attachments







#63

Willyvon

Willyvon

Rob, what's the scoop on that watt meter. I need to measure and monitor the performance of a redesigned blade for my 8 y/o Neuton EM 4.1. I had planned to get a remote display Fluke clamp-on to operate on a loop installed on my security key / removable breaker. The meter is in the $500 range. If this is something I can wire in series without affecting current flow and at a significantly lower cost it's for me!


#64

Willyvon

Willyvon

My simple auditory test results suggest the blade design concept might provide the cutting efficiency necessary to make the need for a better motor in your test mower moot.


#65

R

rscamp

Willyvon said:
Rob, what's the scoop on that watt meter. I need to measure and monitor the performance of a redesigned blade for my 8 y/o Neuton EM 4.1. I had planned to get a remote display Fluke clamp-on to operate on a loop installed on my security key / removable breaker. The meter is in the $500 range. If this is something I can wire in series without affecting current flow and at a significantly lower cost it's for me!
Click to expand...

I recommend this HobbyKing R/C Hobby Store : Watt Meter & Power Analyzer /Watts up (Ver. 2)

It is a power/energy/capacity/voltage/current meter. It needs to connect to both + and - lines to make both the parallel connection to measure voltage and the series connection to measure current.


#66

E

earthworm

Re: CMM1000 replacement brushes

Paul Schruben said:
Now Black and Decker says the CMM1000 brushes are backordered until 3/8/2012. Waiting 9 months for parts is not exactly consumer friendly. I'm ordering the MM1800 brushes. It only costs $16 to find out if they work.
Click to expand...
Probably too late now, but our local ACE sells a great many brush sets generically.
And at, IMO, a fair price...
Of course, they do not have everything...
IMO, Black and Decker are typical American; bad attitude...all profits..


#67

A

Augi

Mark Widmer said:
Thanks for the welcome twall!

Looks like mine is comparable to the Neuton CE6: 19" blade, rear-mounted bag, and rated for mowing 1/3 acre**. But my CMM1000 runs on 24 volts while the CE6 used 36 V. Also, the CE6 battery is easily removable (unlike mine), easy to swap in a 2nd battery for cutting larger lawns ... a newer Black and Decker model has the swappable battery as well.

**These manufacturers' acreage ratings must be under pretty ideal conditions. In practice I can't finish my yard on a single charge, and we have a 1/4 acre, not all of which is grass. Needs a 2 hour recharge halfway through mowing in order to finish up.
Click to expand...

I'm thinking about buying my first cordless mower: B&D SPCM1936. I'm wondering about real life battery life, too. We have about 1/4 acre lot with virtually no slope (back yard has a slight slope for drainage) and it's flat. I had a gas Toro I used for about 10 years; self-propelled, too. It would take me at least an hour or 1.5 hrs. to cut, bag, and empty the bag about 4 times. I'm glad to hear that if I have to, I can get a half charge in 2 hrs. Though that's not cool because ...well just because. Anyone had any experiences with the durability and performance of the B&D SPCM1936 or its cousin the CM1936? Thanks.


#68

R

rscamp

Augi said:
I'm thinking about buying my first cordless mower: B&D SPCM1936. I'm wondering about real life battery life, too. We have about 1/4 acre lot with virtually no slope (back yard has a slight slope for drainage) and it's flat. I had a gas Toro I used for about 10 years; self-propelled, too. It would take me at least an hour or 1.5 hrs. to cut, bag, and empty the bag about 4 times. I'm glad to hear that if I have to, I can get a half charge in 2 hrs. Though that's not cool because ...well just because. Anyone had any experiences with the durability and performance of the B&D SPCM1936 or its cousin the CM1936? Thanks.
Click to expand...

Based on my experience with the original battery this mower would only cut 1/4 acre if the grass wasn't long, wet and/or the cut height was set high. In other words, most of the time it would not finish cutting this size of lawn.

I don't think this is a bad mower and with a better battery it doesn't perform too badly, but to be realistic it has these limitations:

- limited range with the stock battery - this range varies drastically with cut height and the condition of the lawn
- narrower cut width than the average gas mower
- less power than the average gas mower (due to having a lower power motor due to not being supplied with a good battery)

With regard to the last point, with a better battery it could be fitted with a more powerful motor and then there would be no sacrifice in performance compared with a gas mower.


#69

A

Augi

rscamp said:
Based on my experience with the original battery this mower would only cut 1/4 acre if the grass wasn't long, wet and/or the cut height was set high. In other words, most of the time it would not finish cutting this size of lawn.

I don't think this is a bad mower and with a better battery it doesn't perform too badly, but to be realistic it has these limitations:

- limited range with the stock battery - this range varies drastically with cut height and the condition of the lawn
- narrower cut width than the average gas mower
- less power than the average gas mower (due to having a lower power motor due to not being supplied with a good battery)

With regard to the last point, with a better battery it could be fitted with a more powerful motor and then there would be no sacrifice in performance compared with a gas mower.
Click to expand...

Thanks for the response. You said "stock" battery. Is there another B&D battery that is high capacity for the SPCM1936?


#70

R

rscamp

Augi said:
Thanks for the response. You said "stock" battery. Is there another B&D battery that is high capacity for the SPCM1936?
Click to expand...

No. Not that I know of. Mine is home brew. It triples the range at lower weight and provides slightly higher voltage.

I forgot to mention another characteristic of this mower. The self-propelling feature is too fast. It can't be slowed down enough for thick grass. It is easy to push so it isn't a major problem. But it is a bit baffling...


#71

A

Augi

rscamp said:
No. Not that I know of. Mine is home brew. It triples the range at lower weight and provides slightly higher voltage.

I forgot to mention another characteristic of this mower. The self-propelling feature is too fast. It can't be slowed down enough for thick grass. It is easy to push so it isn't a major problem. But it is a bit baffling...
Click to expand...

Thanks, Rob. BTW how do you know when your battery is fully charged? Is there a problem with it siting in the battery compartment? How much more time do you estimate it gives you run time and cutting time? --Augi


#72

R

rscamp

Augi said:
Thanks, Rob. BTW how do you know when your battery is fully charged? Is there a problem with it siting in the battery compartment? How much more time do you estimate it gives you run time and cutting time? --Augi
Click to expand...

If you look at the photos in previous posts you can see the replacement batteries and instrumentation.

http://www.lawnmowerforum.com/new-m...lectric-enthusiast-new-forum-6.html#post60062

http://www.lawnmowerforum.com/new-m...lectric-enthusiast-new-forum-7.html#post60121

Note the replacement batteries sit inside the standard battery enclosure so other than the extra wires sticking out it looks normal and fits the same.

A smart charger takes care of the charging. Full charge equates to about 4.2V/Cell or 42V for this 10s4p arrangement. Maximum capacity is about 20Ah which is twice the rated capacity of 10Ah for the nominal 36V stock lead acid batteries. But the usable capacity of lead acid, particularly under high load, is much less than the rated capacity. Hence the approximate tripling of usable capacity and run time with the replacement battery.

With a "wattmeter" like the one pictured the voltage and power are displayed along with the capacity/energy that has been used. Therefore, how much capacity/energy is left is a simple mental calculation. i.e. capacity at full charge is 20Ah and if 10Ah is used then half the run time is left.

I don't recall how long it takes to cut our approx. 7000 sq ft. lawn. Run time is totally dependent on the load and is somewhat secondary compared with the goal of cutting the grass. :smile: Suffice to say under normal conditions our lawn could be cut twice on a single charge with this battery pack.


Footer Links 1

Top