Reviving a free, dead 12V cordless Black & Decker mower

wogga · 07-13-17, 12:03 PM

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.

07-13-17, 12:03 PM	#36
wogga Lurking Renovator Join Date: Nov 2011 Location: boston area Posts: 7 Thanks: 0 Thanked 1 Time in 1 Post	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.