Mcgregor 36v cordless lawnmower not charging

[Roxyr]

Hi
I would appreciate any advice
Had the lawnmower 3 years worked beautifully... when I took out to charge after the winter the battery wouldn't charge. The charger flashes red to show there is an issue. I would usually think it's battery but the battery has held 80% charge even though wasn't used in last 6 months. So both battery and charger seem fine apart but not together. I mowed half my lawn and then couldn't get the battery to charge and am in danger of growing a jungle in the back garden please help... I am lost what to do. Have cleaned out both connectors and tried a different charging socket

 

[skenk]

I'd start by measuring the battery voltage with a multimeter

 

[Wayners]

Clean and check terminals. My makita drill terminals bend and don't make contact properly, so I have to bend them back up so they make good contact.

 

[ericmark]

It is a problem, as lithium batteries have over charging prevention often built into the battery, rather than in the charger, and I know I had a pair of vacuum cleaners that refused to work again after being in store while we moved house.

Lead acid I have a good idea how it works, but lithium too easy to cause a fire, I cross my fingers my e-bike battery does not fail, as expensive to replace. I have a laptop which has failed due to a mother board fault stopping the battery charging, my only way to use it seems to buy an old laptop to charge the battery in.

 

[Roxyr]

If I knew which one was broken I'd replace it, but both seem fine by themselves