Like Loren, I have the 1315 and have a built in battery charger.  When
driving, the alternator first charges the starter battery and then charges
my auxillary battery bank.  When plugged in to shore power, the battery
charger first charges the auxillary bank and then once they are fully
charged, the starting battery is topped of, although that really is never
needed since I run the radio, etc off the auxillary batteries.  This setup
has worked perfectly since 2009 for me.

Harold

Harold Teer
1991 Westy -- VANGAUX
Harrisonburg, VA

On Tue, Aug 25, 2015 at 2:03 PM, Loren Busch <starwagen@gmail.com> wrote:

> ​RE: 1314 or 1315
> 1314 is one way, engine battery to aux battery only.  1315 is two way.  If
> charging the aux battery (solar?) then when aux battery reaches full charge
> (13.3 v?) the charging source will also top off the engine battery.
> But some have argued that this takes away from getting full charge going to
> the aux battery.
> I have been running with the 1315 for several years now (and with 120 watts
> of solar) and have wondered about this issue.  But with the 1315 and solar
> (plus a battery charger wired in for when I have shore power) I have the
> assurance that my engine battery will start the engine when I need it.
> YMMV
>