Charing 12v batteries with 24v 1.5a charger?

Cody196

Member
Ok si I only got my 48v 3a charger and 24v 1.5a charger and my batteries are not equal voltage, and i want to charge the batteries individually but i only got the two chargers, my 48v charger only charges to an extent, will it work, i put the 24v charger wires to a 12v battery, green light shows up but i havent plugged it into wall as i want to know if it will charge okay and if so for how long?
 

harryS

Well-Known Member
Don't do it. If it's a lead aid battery, you will kill it with 2X the voltage. What's a 12 volt automotive charger cost? $20-30?

With a lithium battery that has voltage protection, you might get away with nothing happening, but the protection circuit might blow up. With a lithium battery with no protection, its world ends in fire and flame.
 

Cody196

Member
Don't do it. If it's a lead aid battery, you will kill it with 2X the voltage. What's a 12 volt automotive charger cost? $20-30?

With a lithium battery that has voltage protection, you might get away with nothing happening, but the protection circuit might blow up. With a lithium battery with no protection, its world ends in fire and flame.
ok so my 4x 12v 7ah batteries i just bought it had a decent range and since i had lsot my old charger and had to leave it super low charge for days til i was able to charge it, now it only will get me a mile on a charge. WTF
 

harryS

Well-Known Member
I see. You have been charging four lead acid cells together in series with a 48V charger. Works if the cells need about the same charge.

When you only have one battery on a 12 volt charger, the current slows down to a trickle as the battery reaches full charge. If you have four on a 48 volt charger, if one battery comes up faster, it will get the same high current as the other three, which is probably not good.

Still, people do it this way. In my opinion, it might be better to put two in series and use the lower current 24 volt charger. Only two batteries to equalize.