I’m working on a project that runs off 58.8V (fully charged) and 225A. This consists of 2 battery packs in parallel with 4 lead acid batteries in series for each pack. The problem I’m facing is that the motor I’m running runs off 10,800 Watts (the motor could go over this value but for a very limited amount of time aka < 10s).
My thought process was that I would log current/voltage and control the throttle using Arduino so I could keep the work exerted by the motor at 10,800 Watts or less.
So if my voltage is at 58.8 and the current being pulled was at 225A the total power would be 13,280 Watts. I would then have the Arduino change the throttle to 81% which should theoretically set the power to the motor at 10,756.
If the voltage dropped, then the throttle would increase.
The challenge here is getting the Arduino the read the proper voltage values! I can get current just fine using a shunt and using Ohms law to calculate current. Getting the voltage however is proving to be difficult. I read online and many suggested to use a voltage divider but the amount of amps that I’m pushing through quickly burns out any resistors that I put in the circuit (As I expected considering that I’m using 00 gauge wire).
I see on Ebay devices that output 300V and 300A values on an LCD screen and just have no clue how they are doing it! There has to be a way of getting the Arduino to read the voltage! heck my multimeter can read the voltage just fine.
Also, the lead acid battery values are based on CCA… and the motor will only run for several seconds at a time.