Remington cordless mower batteries won't hold charge.

[hep2it]

I have a Remington 212B cordless mower that takes a battery pack consisting of two 12V rechargeable batteries. I bought 2 new batteries for it and they were already charged when I got them. They lasted quite a while before I had to charge them again. I used the original charging cable and left it for a few days. When I used the mower again, the batteries started out showing a high charge, but died after a couple of minutes. I tried charging the battery pack indoors, thinking the cold may have played a part, but it didn't help. Brand new batteries. I don't know what I could be doing wrong.

 

[MowerMike]

I assume those are SLA (sealed lead acid) batteries. Some of those older lawn mowers have dumb chargers that can overcharge the batteries if left connected too long. Although your batteries showed a high initial voltage, if they were damaged due to overcharging, they would not hold a charge and would run down quickly.