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ron_dittmer's avatar
ron_dittmer
Explorer III
Oct 13, 2014

Batteries: Two-6V In Series, or Two-12V In Parallel ???

Before spring I will be replacing our two 12V Walmart coach batteries. Our 7 year old rig has it's original Tripplite 2000 watt inverter/charger similar to THIS ONE. I was thinking of replacing the ...
Class C
DiploStrat's avatar
DiploStrat
Explorer
Oct 15, 2014
map40 wrote:

Strange, the explanation is done by a website that belongs to a company that has a better solution than common isolators. Are they giving you the real deal or just trying to sell you something....?
No batteries are exactly alike. They WILL pry on each other, or loose power, or many other problems. Ergo my suggestion, install 2 6V batteries and avoid buying the BETTER isolators all together...


All batteries will seek to reach a common voltage; it makes no difference if they are 6v or 12v, or even the 2v cells that make up your 6 or 12 volt battery. This will happen whether they are connected in series or parallel.

SmartGauge simply sells one of many intelligent relay controllers. I don't use their product, but rather a similar product made by Magnum Energy, their Smart Battery Combiner. If you don't want to use them as as source of instruction, try the Lifeline Battery Technical Manual. Start reading on page 14.

The only reason we isolate batteries on an RV is that we are afraid (sometimes with good reason) that we will draw down the camper battery so much that it will, in turn, draw down the starter battery to the point that we cannot start the vehicle. Thus the market is full of products designed to separate starting batteries from camper/RV/house batteries. Each of these products has advantages and disadvantages. As a general rule, however, you do not want to isolate the batteries in your camper battery bank one from the other. In fact, I can think of no good reason to do so.

Carried one step further, my truck has 140Ah of starter battery and 600Ah of camper battery. If I stick to the 50% rule, then even drawn down 50%, my camper battery bank is twice the size of my starter battery. I do, in fact, use an intelligent relay to separate the camper battery from the starter battery, but that relay is closed more often than it is open.

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