[Guest]

Any charger that will charge up a single 100 AH Prismatic Cell? I need a way to charge up single batteries to bring a few up to balance with the others. If it takes a month so be it. Since I have no way to bottom balance or discharge my batteries properly I will try to do a top charge. Any ideas? I see no chargers on the list anywhere to do this.

Either I need a way to discharge or to charge up single batteries to a specified voltage.

Also does anyone know what the resting voltage for the lithiums should be?

Pete

With out a CC CV charger I am unable to control the charge. I pulled a battery to 4.1 volts but as soon as it was removed from the charger the battery went back down to 3.37 volts. I have no way to hold a voltage while the amperage slowly drops while the battery charges. Mine just increases the voltage as the amperage drops and it will go into over load if not watched.

I need a proper single charger. Got one?

 

[Weisheimer]

Any charger that will charge up a single 100 AH Prismatic Cell? I need a way to charge up single batteries to bring a few up to balance with the others. If it takes a month so be it....

You can use a "bench supply" or a "lab supply" to do that. You would want it to have accurate voltage settings and adjustable current limiting.

Something like this, though there a million choices. There are similar used ones on ebay for under US$100.00

http://www.bkprecision.com/products...programmable-dc-supply-w-rs232-interface.html

 

[EVfun]

Since I know top balance is not your favorite idea I have something that may allow a type of mid-charge balance. If you parallel all the cells even very small voltage differences will move current over time. I would think that in parallel they would slowly move toward balance even at 3.3 volts.

If you are hitting them with a charger in parallel I would connect the batteries to the charger like this so the resistance between each cell and the charger is the same.

charger--------------------------        
        |     |     |     |     |        
     |  +  |  +  |  +  |  +  |  +  |     
     |     |     |     |     |     |     
     |     |     |     |     |     |     
     |  -  |  -  |  -  |  -  |  -  |     
        |     |     |     |     |        
        --------------------------charger

I've considered charging like this for about an hour a day as I don't want the cells to spend days over 3.4 volts to equalize. I'm planning to get the lead out of my Buggy. Since it is only an hour a day I can use a cheap dumb 6 volt charger with a little resistance in series. With a single lithium battery reg I can have it make a buzzer squeal if the voltage gets to 4 volts. I can charge while working on my EV in the garage.