TV alternators of ANY size are designed to maintain the thin plate lightly depleted starting battery at 13.6 volts, not to quickly recharge a depleted thick plate battery through 20 or more feet of smallish wire. To recharge a trailer battery that is down more than 20%, needs over 14 volts or it takes many hours to trickle charge it at 13.6 volts. Getting a full 13.6 volts to a depleted trailer battery is impossible with the size wire in the TV.
Even the converter in my Bullet won't put out it's bulk charge voltage of 14.4 volts for more than a few minutes unless the battery is way down because Keystone put the converter so far away from the batteries
. It quickly drops to 13.6 volts at less than 5 amps and trickles it in.
Next mod is splitting the power panel from the converter and putting the converter forward nearer the batteries where it should be.
