Date:         Wed, 17 Dec 2014 17:45:04 -0800
Reply-To:     Alistair Bell <albell@SHAW.CA>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Alistair Bell <albell@SHAW.CA>
Subject:      Re: Battery Charging
Comments: To: "sailingfc @dslextreme.com" <sailingfc@DSLEXTREME.COM>
In-Reply-To:  <CAJ-pOoa7HEnreCEWGF+NmmJxsiBAuUi-X_yqnotkw1Lrcbtm6g@mail.gmail.com>
Content-Type: text/plain; charset=us-ascii

Here is what is working for me, for the last few years.

I'm using a small agm (30 Ahr) battery as my house battery. I have a blue seas ACR connecting my house and starting battery. I have the house battery wired to the van through an auxiliary fuse panel which then distributes to various devices, but notably I send juice to the circuit that was protected by fuse #3 on the main fuse panel. So that circuit gets power exclusively from the house battery.

I have a promariner charger wired into this circuit. I also have a solar charge controller in this circuit. I've been experimenting with a smallish (55W) panel this last summer.

I have an adjustable voltage regulator in my alternator, set at approx 14.6 V. I believe this setting, especially since I note that the set voltage does decrease as the alternator get hot, is not high enough to endanger my starting battery. It is a good charge for my AGM. Most battery makers supply a fair bit of info on charging and float voltage data.

If was to be doing extensive long duration driving, I might adjust my voltage reg down to 14.5  to reduce my worry about excessive charging, but as I don't do that I don't adjust.

What I do though, is plug in the promariner charger every week to make sure I am keeping the house battery happy.

The set up as described is working for me with this small house battery. I have a very much larger battery I have yet to install and that might change a few things in the system. For sure the solar panel will be undersized ( worked like a champ this last summer with the small battery) and so will the promariner charger.

Drop me a line if you want a link to a sketch of my wiring.

Alistair



> On Dec 16, 2014, at 4:52 PM, sailingfc @dslextreme.com <sailingfc@DSLEXTREME.COM> wrote:
> 
> With all the talk about second batteries and house batteries, what about
> charging these things.  I understand that SLAs and AGMs need to float after
> they reach full charge.  What circuitry have people added to taper the
> current and float their batteries?
> 
> I use a 110V smart charger at home to keep my "bench top" 12V SLA battery
> topped up.  Seems inefficient to get an inverted to use my 110V smart
> charger in the van.
> 
> Thanks.
> 
> -Dick-
> 87 Syncro (Blaze)