Saturday, Aug 25, 2012 at 16:10
Yes Cap, you can connect both batteries together and charge them simultaneously from the alternator. The Redarc BCDC-1220 would be best positioned close to and just before the vehicle auxiliary battery and both aux batteries charged from its output.
You should note though that the BCDC-1220 has a maximum output of 20 amps which will be shared between the two batteries. There is also the problem of voltage drop in the wiring supplying the camper battery.
A more ideal solution is to employ two Redarc BCDC-1220's, one for each battery and positioned close to each battery with both BCDC-1220's supplied from the alternator. That arrangement overcomes volt drop in the wiring and will look after your batteries much better. The BCDC-1220 will operate with 20 amp output even though the input may be as low as 9 volts. This is not an excuse to use grossly undersized cables however as the losses with place a higher load on your alternator.
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