Plum Quick Quit-Series Motor Recommendations

[JohnnieB]

Originally Posted by Bmatlock00

Sounds like a good option, I also pull this passenger trailer around sometimes and could use the extra torque. Now for a question for JohnnieB, you might remember the trailer when I built it and we discussed adding a battery pack to the trailer for added range. Am I correct that I would not need to use them same AH capacity batteries in the trailer if they are wired in parallell with the cart batteries and I charge the packs seperately?

Am I correct that "Them" should be "The"?

It would be best if all the batteries were the same make and model and age, but I doubt if you are going to run down to the local battery store and buy a dozen 8V or sixteen 6V (or two sets whatever you are using to get 48V), so the older set will have fewer AH even if the are the same make and model as the newer set.

The AH of battery pack in the cart and the AH of battery pack in the trailer ought to be as closely matched as practical since the amp draw from both packs will be roughly the same, or at least try to be, which means the lower AH set might be discharged faster. On the other hand, the internal resistance of the lesser AH pack may be higher, so the lesser AH pack might produce fewer amps, so the SoC of both sets may stay about the same.

Actually, the SoC will stay the same because the two pack are in parallel, so the voltage across each series set will be the same, less any voltage drop due to the resistance in the cables connecting the two set in parallel. So it will probably work okay as long as the AH aren't grossly mismatched.

Okay to use separate chargers when the packs are not connected, but when the are, only use one charger.

Also, try to have the pack voltages closely natch when connecting in parallel. If they aren't, you will get some pretty significant arcing since the two pack voltages will instantly equalize. The amp flow will be the difference in voltage divided by the resistance of the interconnecting cables.

It might be a good idea to put a super-duty solenoid in one of the cables that is energized when the cart's keyswitch is turned on. That way the plug that connects the trailer to the cart is dead when you plug it together and the arc is handled by the solenoid contacts, which are designed for the purpose. You could also bridge the solenoid contacts with a resistor whose ohmic value minimized the arc when connecting the trailer to cart and slowly equalized the two pack voltages so the solenoid contacts are not hit as hard when the key is turned on. ( Same concept as the pre-charge resistor on the main solenoid feeding the controller.)

[benjylafond]

Did you call Plum Quick about rebuilding your motor? A buddy of mine just had his PQ motor rebuilt by them for $75.00 + shipping.