2x 6V batteries or 1 large 12V

Purchasing house batteries this week and have settled on either:

2x Lifeline AGM 6V GPL-4CT 220Ah (120 lbs total) or
A single Lifeline AGM 12V GPL 8DL 255Ah (156 lbs total)

Anything I need to know about mounting these batteries in a van? I plan to strap them to the floor with marine brackets (bolted through the floor to a reinforced support bar) and use heavy duty nylon tie down ratchet straps.

Do they need to be mounted in a battery box? Any reason to choose one setup over the other besides the weight savings of the 6V?

I went with a Fullriver 12D battery to just have to deal with one battery and one set of connections. Plus it fit nicely under one of my cabinets. The deciding factor was mostly where it would fit into the build. My preference was for one battery and it worked out for me. I can see doing it either way and each build sometimes dictates what needs to be done.

Either will fit for my application since these are going under one of the rear bench seats next to the wheel well. How did you hold down the battery? I would probably use 4 straps for the 12.

mbsprinter144 said:

Any reason to choose one setup over the other besides the weight savings of the 6V?

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Nothing major..

Pros of single large 12V battery:
- avoids cost and hassle of making an additional cable to join the two 6v batteries

Pros of 2x 6V batteries:
- more flexibility to squeeze the batteries into a limited volume
- easier to lift two smaller batteries during initial installation

AGMs don't really need to go in a box, but any type of battery should be well-secured.

Personally, I prefer having as few batteries as is practical.

What's your cost difference between the two?

In the flooded battery world, a pair of 6v golf cart batteries tends to be cheaper than on big battery because of golf carts! It's just the most common size, and is available everywhere.

I'd go with one big AGM for the simplicity. I do think a pair of 6v batteries will be much easier to change during a road trip. Everyone sells that size. If you plan on doing remote 5k mile trips, that could be helpful.

$600 total for two 6V and $645 for one 12V. So basically the same price. The ease of moving around two 6V sounds nice but the simplicity of a single 12V would be nice. The single is slightly more Ah (and a little more weight).

I have a single 12 volt 255 amp-hr 8D battery. Install is simpler. On a 148" WB 08 Sprinter the battery fits behind the driver side wheel well and the back doors if elevated about 3". Just slide it in on the floor. My sold 08 Sprinter still has the original 8D battery so if you charge it properly do not be concerned about moving it.

Graphite Dave said:

I have a single 12 volt 255 amp-hr 8D battery. Install is simpler. On a 148" WB 08 Sprinter the battery fits behind the driver side wheel well and the back doors if elevated about 3". Just slide it in on the floor. My sold 08 Sprinter still has the original 8D battery so if you charge it properly do not be concerned about moving it.

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How did you strap yours down?

If reasonable, always go with the fewest batteries possible. Fewer connections, no wiring to resistance balance, only one set of tiedowns. If you need to suddenly replace a lifeline battery, you are doing something VERY wrong.

An 8D lifeline is heavy, but you will install it, and it won't be touched for many years with good treatment. I have seen 8 year old installs still running strong.

I guess to some extent it depends on how much you enjoy lifting batteries and risking injury over some lead in a plastic box.

I like the concept of 8Ds but putting them into place is outside of my current physical condition and you can easily hurt your back moving them around.

Regardless of which setup you use, the terminals need to be protected from accidental shorts.

In case it is ever interesting, Rolls makes an 8D that comes in 2 volt sub sections designed to be relatively easily dropped into place in an 8D like case. It is pretty a pretty clever setup in easy to lift components. I don't remember at the moment if it was a flooded or AGM setup.

HarryN said:

I guess to some extent it depends on how much you enjoy lifting batteries and risking injury over some lead in a plastic box.

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When you buy the battery have the shop put it on the van floor. Then one person can slide the battery on the floor into its final location. Lifting not required. At 78 years old I did it without help. In about 10 years if I am still alive, I will repeat the process.

MBSprinter: I do not remember. Will look next weekend at Concow when I get to see the sold Sprinter again. On the Transit the battery is on the floor inside the bench seat in front of the driver side rear wheel well. I made hold downs out of 1 1/2" 80/20 that are bolted to the 80/20 seat structure. Blocked the front and back with stops bolted to the 80/20. You appreciate building stuff out of 80/20 because there is always a place to anchor something.

Anyone know the difference between the GPL-8DA vs GPL-8DL? or which one would be better for a house battery application?

"The GPL-8DL is designed for charging amperages up to 637.5 amps or 250% of the rated Amp Hour Capacity due to low battery internal resistance"

I will answer my own question. So the part number ending in L is for a lug and ending in A is for an automotive terminal.

You want the lug tab. Not automotive.