I think one of the reasons my lawnmowers seems to go through so many batteries is my yard is so bumpy (and large tree roots) there is no suspension on a typical residential lawnmower. As mentioned, it shakes the hell out of it and because plates are no longer made of solid lead but plastic coated lead, the lead eventually flakes off and kills a cell.
My father seems to get more than 5 years out of lawnmower battery but his yard is smooth. He's got a John Deere he has had for more than 5 years and it still has the original battery.
One of the worst brand batteries I've ever seen are those ones labeled "Economy". The name says it all. That is what's currently on this Troy Bilt that has a dead cell. I have no idea how old it is. I have to jump start it using a battery charger with a start mode setting. I don't know who makes this battery. I thinking this is one of Exides reject batteries. I had one last 2 years on a car.
On the other hand, I had one of these "Economy" batteries on my Fiat Spider. I had it hooked to a trickle charger over the winter and it died at some point. It had a sticker labeled 11/11 so I guess it lasted 7 years which maybe good. I tried charging it but after 24 hours, the best charge it would hold was 4 volts.
But it might be the trickle charger itself. I had this same trickle charger connected to my Subaru last year (I drive my classic cars in the summer and park my Subaru from May to November) and it's battery went dead in 3 months for no apparent reason. However I was able to recharge it and it made it through last winter which was bitter cold. The trickle charger works, it's putting out 13.5 volts but maybe I need to disconnect the negative terminal from the battery itself. I would not imagine the radio memory would pull more amps than the trickle charger. Any ideas on that?
One the flip side, my 68 Ford has sat for 2 years without being started. I had a trickle charger connected to it and the battery on it had a full charge.
Sorry if I am mixing cars and lawnmower batteries but I am curious.
Not quite correct.
Battery plates are all solid lead.
Two different alloys of lead, depending upon what type of battery they are Pb/Sb, Pb/Au , Pb/Ca.
The seperator plates are plastic.
What has happened is back in 76 when I worked for a battery maker, the plates were 3mm thick.
By the time I left they were 0,5mm thick.
The reason ?
Car makers demanding lighter batteries.
Thinner plates are substantially weaker but most will run 2 years long enough to be out of warranty ( the ghost of Henry Ford rides again ).
This is why I always use spiral cell batteries if I can get one to fit.
My commercial customers run Optima batteries and while it was a hard sell to get them to fit a $ 250 battery they are all very pleased with them.
A team doing nothing for 2 hours while some one races out & gets a new battery costs a bomb and with 600CCA the engine all start up in a flash.
One customer ran 3 days on a fully charged battery after his alternator packed it in , he was amazed.