Originally Posted by twinboat
A late model Grand Cherokee, like the OP tows with, has a 160 amp alternator as standard equipment, with options up to 200 amps.
With at least 80 amps available, he can charge his 80 AH trailer battery with booster cables, without worrying about overloading and overheating his alternator.
Just don't turn on every electrical item in the Jeep while doing it.
But the trick is how to limit the alternator to just 80 amps or less 😃
It WILL ramp the amps up to max in an attempt to get the voltage to 14.2 or higher
depending upon temperature.
which on a severely discharged battery will not happen for awhile. You may feel comfortable risking your equipment .....however it is a substantial risk that damage will occur if the load is maintained long enough to overheat the diodes.
Better to get something like Amp-l-Start, which will limit the charging amps to 15, and then there is no worry.