Thread: Dual Battery System not charging Auxiliary Battery

Hi Feral, you need to get voltage regulator/alternator checked because ( excluding the D3 ) all vehicles MUST produce no less than 13.8 volts or the battery(s) will never fully charge.

The average voltage of most vehicles is 14 to 14.2, for yours to be running at as low as 12.8, there is something seriously wrong with your alternator.

Being a new one, the voltage reg is probably built in and if it is new then it should still be under warranty.

By the way, although wet cell batteries can be safely charged with up to 14.7 volts, most AGM batteries will not tolerate that high a charging voltage so if you alternator can be adjusted, keep the maximum voltage to about 14.4 volts. This will resolve your charging problems.

One more point, it is nothing more than a myth regarding not being able to fully charge an automotive battery using an alternator IF the alternator is working properly and yours is not.

Cheers

Hi Jamo, yours should work perfectly as the voltage setting on the SC40-LR and SC80-LR were developed with LRAs assistance so I had an inside track but there have been some additional changes and this is what is stuffing up all the opposition.

The advantage the SC40-LR and SC80-LR is based on a combination of the way the settings work and the fact that they don’t just shut down when the engine is turned off, making sure you won’t have problems, even if there is a software upgrade at some time, that changes the current operating voltage setting in the D3.

Cheers