Yes, well if one is hard on a battery (use it below 50% often) it will die. If you've not been constantly trickle charging it (solar panel?) then that was hard on it also. You were doing something right if you got 7 years out of it - congratulations...

I would try a desulfator after a good slow charge to bring it up to 13 or 14. The desulfating takes a week or more to work sometimes. Also be sure to check that your mower connections are clean and tight, that your mower motor is oiled, blade is sharp (file works on removed blade just after you oiled the bearing by a few drops of the correct oil on the central shaft) and that your battery acid level is not low (if the battery cells can be accessed - not possible on AGM and some SLA units) If that doesn't work, you don't need a new mower...you just need a new single $50 battery. multiple batteries is always worse than a single one when replacing.

I just replaced my 29AH battery in my 12v Black and Decker mower. I got 10 years out of it. It was constantly trickle charged. It was used on a 6,000 sq ft property (grass area less of course - house is about 2000 sq ft 2 floor) for 10 years 1x a week. 10 years is rather good; the battery guy congratulated me. The battery was $90 in store vs $50 online.

I did get my solar panels working again (45 w this time, because I had a Harbor Freight kit lying around). The mower charges in a day or two and i can plug 12v devices into a port I made on the mower, so now there's 12v lighting in the garage!

New battery seems to be okay - I might try an online battery next time. The almost twice more money local battery doesn't seem anything super powerful - A Duracell 29AH from BatteriesPlus - $90 with coupon.

9 lives
 

Just a post-script, WELL after the fact...

I put the mower & charger at the curb on our little city's "treasure hunt" garbage day with a sign on it saying "works, but needs new battery".

It was gone within an hour.

So for all we know, someone has resurrected it, and it's living its 3rd or 4th life! Meow.

Necro bump. But, having your experience, would you recommend a battery powered mower over a gas powered mower?

I don't have direct experience but I've used a corded Black and Decker electric mower that I got for about $20 with a bad top bearing that caused the rotor to grind into the permanent magnet and tore apart the magnet a bit and jammed it into the rotor. I fished out all of the broken chunks of magnet and replaced the top bearing with a random grease type ball bearing on the top. I didn't expect it to work and the bearing was very draggy but it worked. I used it for two years consistently until I got a gas mower from my mom's house.

I love that it can grind through grass twice as high as my "6.5 horsepower" 21" lawn mower and I can actually get the mowing done on tall grass 10 minutes faster than the gas mower because I can walk as fast as I want because it won't stall out or even really slow down like a gas engine does.

With the experience I've had of using the corded model, I've always wanted a cordless one but I just couldn't justify replacing a working gas mower with one in the $200-650 range. It's getting mighty enticing though because the newest cordless mowers have 21" mower decks instead of the 18" mower decks, they have self-propelled and mulching functions and advertise being able to cut a 1/3 acre of grass. So basically now the cordless mowers are now a non-compromise option with all of the standard features you'd expect in a mower. I suppose I've always wondered how much juice my 1/4 acre lot uses. I know some market themselves as coming with a battery and having a caddy so you can swap in a second battery but don't come with that second battery, which makes me wonder if I need a second battery or not and I don't see the guidance on either runtime or average cut sq footage on a charge. If I get 75% done with the yard and need to plug in for an hour to do the rest, it wouldn't be worth it if it means I'm shelling out for a bigger battery, but I don't know what to expect.

I wouldn't touch a lead-acid one though unless I had a NiMh or lithium retrofit project planned for it, I'm sure I'll do what I normally do and wait to find a used lithium one on Craigslist from someone with a bigger yard than mine and ask about the battery performance.

Like so many things, it depends.


I've owned many types of mowers: manual, gas, battery & corded electric. (All at the same time!)



I prefer the relative quiet & better reliability of the electric mowers. They're also lighter and easier to use.



Pure economics probably favours gas mowers, at least comparing to the old lead-acid-powered mowers I had. The much more durable lithium batteries you can get today may have tipped the total cost of ownership balance though. Environmental impact probably favours electrics.


My gas mower is far more powerful than my electrics, though. You can let the grass grow longer between cuts, so it's arguably more convenient that way.


Currently I use a gas mower on one larger lot and a corded electric (and sometimes the manual reel mower) on 2 smaller lots that I look after.