I have also seen key switches, main contactors, and some times epo switches cause this codes. I have installed a capacitor to help with static electricity on these trucks.

The code 19 relates to an under voltage at the traction controller. With a battery problem you would also see a code 32 for the lift controller. Are you having to charge the battery shortly after this happens? If so you may need to have the BDI cut out adjusted to keep the battery from getting low to set this code.