[mkmike]

Hi. I don't know if this is the place for this, but I thought someone might could give me a little insight.

I am working on a small electric vehicle, and we are running into the problem of a few too many volts for the controller. Due to some oversight in our planning, we are running five 12v batteries into a Kelly controller that has a rating of up to 60v. Because of the slightly higher charge in each battery, the total voltage exceeds the 60v by about 5v causing the controller not to work. The Kelly controller can take up to 130v so we aren't worried about blowing it, we are just trying to get it to work right at 60v.

My question would be then, is there any way to lower the total voltage by about 5v? I know we could use a resistor, but we don't want all that loss associated with a resistor.

Thanks for any help.

 

[brian_]

A resistor to drop some of the voltage is definitely a terrible idea, and a more sophisticated solution would probably cost as much as a new and more appropriate controller. Why not just run four "12 volt" batteries, for 48 volts nominal (and over 52 volts at full charge)?

Maybe knowing more about the controller would help - which Kelly Controller model is it?

 

[ishiwgao]

Because of the slightly higher charge in each battery, the total voltage exceeds the 60v by about 5v causing the controller not to work.

The Kelly controller can take up to 130v so we aren't worried about blowing it, we are just trying to get it to work right at 60v.

The 2 statements above sound very contradictory with many half-information (i wouldn't call them untrue).

1) What do you mean by the controller will not work at 65V since it can handle up to 130V? I know there is definitely some allowance for overvoltage protection, but it wouldnt be double the rated voltage right?

2) Why don't just run at a higher voltage (65V) with the controller?

3) Is there a reason why you are choosing specifically 60V? competition rules? safety rules?