The first part of your problem may be the problem. If the rectifiers bad then the ignition system may not be getting the correct voltage to run. Also constant bulk charge from a charger will do the battery in, car batteries are not happy dropping below 90%charge and may not recover from 70% or below, they will certainly be damaged and the point where we all say "shit where's the charger" is normally below that .
You have to fix that first, it may be separate. My old DT had a completely isolated ig system. Great! saved me walking a couple of times off road when nothing else worked.....
Anyway the TDR on the other hand, thats different. Bad battery then things go all to ratshit in a hand cart with weird missfires and stupid powervalve opperation.
May not be what you wanted to hear but.....Fix the rectifier....