TT battery

gheicher wrote:

LewBob wrote:
I have been quite satisfied with my Battery Minder. I take the two 12-volt batteries off the trailer and into the garage (for convenience), hook them to the Minder and check water level, just in case, about once a month.

When charging multiple batteries, it is my understanding that it is best to charge the battery individually and a bit risky to hook batteries directly in parallel. A diode should be used for isolation in case the batteries are at different charging levels.

Hi gheicher,

I agree with you, if you have 2 separate batteries that have very different states of charge, say one at 50% and one at 95%, it would be better to charge each separately. The charging needs of that big a difference can be a factor.

That said those of us who boondock off the grid have multiple batteries hooked in parallel on the camper. Some 2, some 3 and some 4. However there are ways to hook them in parallel that are better for a more balance equal discharge and charge. See here,

http://www.smartgauge.co.uk/batt_con.html

I also have 2, group 27 deep cells on the camper and hook them up in parallel, however this way, notice where the battery leads are to the camper in relation to the battery posts.


By following that method both batteries are forced to discharge and charge a lot more equal than the older way of tagging onto the 1st battery and then jumping to the second.

When it comes time to add a heavy charge, both batteries are equally discharged so charging can now be at higher rates of as each battery is forced to accept the the same charge rate. Ideally the amp hour capacity and the age of the batteries are the same.

Like LewBob, when I store the camper away from power in the winter, I take the 2 batteries home along with the interconnection cables and hook the cable and the VDC battery minder up to both like the TT converter would in the method of parallel like I showed above.

These battery minders only put out 1.3 amps and are not made to bring a deeply discharge battery back up, you do that with a stand alone changer, then put the battery minder on to keep the voltage at float stage and adds a little charge if needed.

Hope this helps explain what LewBob may be doing and others running multiple battery setups.

John