[electro wrks]

I have finished my 1994 Ford Ranger pickup and have taken it out on several road test it works fine at speeds around town but on the highway it is extremely hard to get it up to 50 mph. There is another problem too it seems to be run down the batteries (even at low speeds) in the first battery box more than the other batteries in the other battery boxes the voltage on those batteries is lower than the batteries in the other boxes. I have Lithium Ion CALB 100ah batteries and a BMS system a Soliton Jr. controller with a Warp11 motor. I have wrecked three batteries just test driving around and can't afford many more test drives at this pace. I can't figure what is wrong with my build and am tired of going around in circles and never getting any closer to solving the problem. I don't know if I got a bad batch of batteries or I did something else wrong the BMS system alarms when a battery's voltage gets around 2.65 or so at least that part works right but what causes that to happen?

You seem to have problems with even very basic conversion details. Maybe you should stop and start over by showing us photos of the components of the conversion and how they're put together. Or, at least, list the parts and how they're put together. For example the motor, adapter plate, clutch, coupling ,transmission, drive line, final drive ratio. connectors, etc. wire size, Maybe I missed these details. Do you have a build thread on this forum or others?

Some details on the battery cells would be helpful. Were they purchased at different times? Have some been sitting around for along time? Are you sure they're all the same? Maybe they need to be paralleled and slowly charged to just below the max charge voltage and monitored for excess temperature and swelling. You should do this before any more cells are wasted. Also, with the larger motor and controller, you may be discharging the cells at or near their recommended maximum. You may have to limit the discharge current or think about getting larger cells.