Originally Posted by Singinius
I have a heavily modified Cushman 36v cart and I am wondering if someone can help me understand what I need to do to be able to charge the batteries while I am driving it?
I have a Honda 3000 generator that mounts on the vehicle and I have changed out the lead acid batteries with AGM batteries and it is my understanding that these batteries should be able to handle this kind of configuration. (http://www.sunxtender.com/solarbattery.php?id=18
) (battery model might be slightly different than that link but its essentially the same one)
I have the stock charger that came with the cart and I have a Schauer JAC2036 20 amp 36v charger which I have not used yet.
Otherwise the motor and controller should be the stock ones that came with the cart. The frame of the vehicle has been heavily modified and it is carrying a lot more weight than normal. I would like to be able to run the generator while I am driving the vehicle and be able to charge the batteries at the same time.
I would appreciate any advice?
Why do you want to do this?
Basically you can't charge and use a battery at the same time. Using a battery is discharging it, which is the opposite of charging it. So what will happen when you put a charger on the battery while it is being used is that there will result a net charge rate or current which either charges or discharges the battery. Call it positive current which charges and negative current which discharges the battery. If the load (motor propelling the vehicle) current is more than the charger output current, the net current is negative and the battery discharges. If the charger current is more than the load, the battery charges with the positive net current.
So your charger current is 20 Amps. At 36 volts, that is 720 Watts (20A * 36V). 720W is less than one horsepower (1hp = 746W). So the maximum power the motor could use to propel the vehicle and have a net positive current to actually charge the battery would be less than one hp, probably close to 1/2 hp.
So with the equipment you describe, to charge the battery while driving, you need to go so slow as to use less than 1/2 hp. It probably is not possible for you to even move that vehicle with that little power.
And another thing, the battery charger may not work properly when the traction circuit is on. It depends on the particular charger.
You would be better off using all electric or all gas engine for propulsion.