48V charge issues, how to verify?

[ntxdba]

I have a 48V MPT that was given to me by a friend. Not sure of the age of the batteries but they have set for awhile. In order to get the 48V charger working last summer, first year for me, I had to connect a 6V6A battery charger to several of the batteries to get a surface charge that would allow the 48V to turn on. It run okay last year, not a lot of oomph but enough to use around the house and neighborhood.

I attempted to drive it a couple of weeks ago and it would hardly move, after a full 48V charge over night. Most batteries registered around 6.3v, but two were at 4.5v. I was preparing to replace them and decided to use a hydrometer to check them. All cells checked out as good in all batteries.

I took the 6V6A charger and connected to each of the 4.5v cells and it was able to charge each to 6.8 ~ 6.9. I then connected it to several of the other batteries with the same results, voltages in the high 6's.

When I plug the 48v charger in to charge however it still only charges to about 6.25 volts per battery. Is there a way I can test the charger to verify it is charging correctly? I comes on when I plug it into the wall and the cart, but doesn't charge the batteries as a pack as high as the individual charges does.

Also should the charge drop quickly when only using the 6V6A charger? I'm talking within several hours of sitting.

[Clemsoncartguy]

Shouldn't drop below that 6.3ish without useing it. Sure they will be high as soon as disconnected and within a few hours be down to that 6.3 level or so but not down to 4. That's dead as a door nail

[ntxdba]

Is there a way to test the charger to see if there is an issue?

[teecro]

When you charge the batteries individually let them sit untouched for 12 hours then report their voltage... If they drop below 6.2 volts they are toast...

[ntxdba]

Thanks Teecro, I just checked my charger. When it firsts starts to charge its only hitting 10amps and 51.9 volts output, checked at the battery pack.

[teecro]

Originally Posted by ntxdba

Thanks Teecro, I just checked my charger. When it firsts starts to charge its only hitting 10amps and 51.9 volts output, checked at the battery pack.

Unless you can check what the voltage peaked at during the charge checking voltage while charging tells little to nothing... As requested let your charger fully charge your batteries, up to 16 hours. Let cart sit untouched for 8 to 12 hours then report your voltages....

[Clemsoncartguy]

I'd you aren't driving this cart say 10 miles or more between a charge your not really charging anything if it's just sitting it's barely doing anything. Just a little charge for an hour or so and it cuts off.