I recently salvaged an older hoverboard from my local Goodwill. It did not come with a charger and would not turn on. I figured the battery was dead and I bought it for $5 assuming I might be able to examine said battery pack and replace any dead 18650 cells. The battery pack inside was a 6sP1 configuration of 18650 cells, as expected (the charging port was labeled as 22.1v). I replaced 4 dead cells and left two cells in place as they were able to receive a charge and were holding about 3.6v on them. The only thing left to do is find a replacement charger. I found a pretty cheap one on eBay for about $10 after shipping. It says it has over current and over voltage protection. It fits the port size nicely. Here is the link...
Ebay charger.
I can't think of a reason this charger wouldn't work, but I just wanted to get someone else's opinion. Thanks.

 

It is Li-ion charger, it has 2A charging current, should be fine.. only on the photos it says 2.1V output voltage but I guess that is some mistake of the photo.

 

I would recommend that you charge it only outside, far from anything flammable.

 

It is Li-ion charger, it has 2A charging current, should be fine.. only on the photos it says 2.1V output voltage but I guess that is some mistake of the photo.

Thanks for the reply. Much appreciated.

 

I would recommend that you charge it only outside, far from anything flammable.

Duly noted. Good idea. thanks for the reply.

 

My serious advice is that you pay close attention to the battery temperatureduring charging the first few times. The batteries will get warm eventually, but if they get HOT then the charging current is too much.