Although the mini one will charge your battery well enough, heavy drain by using lights, spots, stereo and heater may draw faster than the little mini alternator can top it up.
As I said earlier, you should get 14.4V at the battery with your engine running.
However, it is still OK if you get 13.8V ... anything lower is not good!
As I said earlier, you should get 14.4V at the battery with your engine running.
However, it is still OK if you get 13.8V ... anything lower is not good!
Are you using 2x6V batteries or a pair of 12V in parallel?
Because the lowest condition battery will 'drain' the other down to it's level, hence you only getting 12.6 at rest and 14.04 on full charge.
Try taking one off at a time and compare the charge and static voltages.
You may be surprised at the results!
12 volts parallel mate why ?