Dual 12v or 2 6v Batteries?

[Mike Adams]

We are thinking about boondocking in out 2600 and want extra power.
We can get AGM batteries, but I need help on 2x12v vs 2x6v. The pros I
Have heard for 2x 6v is added amp hours but if one of the 6v has an issue you have no power.
With 2x12v in parallel (unlike the 6v in series) I would think the added amp hours of
2 batteries would be an advantage, and if you have one fail, the other can support
You.

Thoughts? Experience to share?

[Cate&Rob]

Mike - you have done a really good job of summing up the pros and cons of each.

If you look at $/Ah, the 6V scenario will probably be a little cheaper. If you look at number of charge/discharge cycles, again the 6V scenario will win out because the plates are thicker. If you look at weight/Ah, the 12V scenario will be lighter. I went with two 12V for the reason you describe . . . I can lose one battery (usually one cell in one battery) and still be able to run all the things on the RV that need relatively low current 12V. Fridge, water heater, furnace, lights, etc.

Rob

[Paul & Deb]

Sounds like you have a clear understanding. there are pros and cons to each and the decision is left up to you which setup works best for you.

There are some who have a 2 6v setup and then a battery selector switch and a 12v battery that can be used if they have a failure of a 6v.

I have 2 - 6volts but realize if 1 goes bad I am without until I can replace it.

[LCBoyer]

We are thinking about boondocking in out 2600 and want extra power.
We can get AGM batteries, but I need help on 2x12v vs 2x6v. The pros I
Have heard for 2x 6v is added amp hours but if one of the 6v has an issue you have no power.
With 2x12v in parallel (unlike the 6v in series) I would think the added amp hours of
2 batteries would be an advantage, and if you have one fail, the other can support
You.

Thoughts? Experience to share?

Two six volt batteries have a better Reserve. You are correct, if one fails, you are out of business

[klenger]

Two 6 volt batteries in series doubles the voltage to 12 volts but the amp-hours do not add. In other words, two 6 volt 220 amp-hour golf cart batteries will give you 220 amp-hours at 12 volts.

Two 12 volt batteries in parallel doubles the amp-hours but the voltage stays the same at 12 volts (which is what we want). Two 110 amp-hour 12 volt batteries wired in parallel will give you 220 amp hours at 12 volts.

Note that the end result is the same, assuming that the amp-hour rating of the 6 volt batteries and 12 volt batteries is the same. You don't get something for nothing with either scheme. Personally, I prefer 6 volt batteries because they are usually better suited to deep cycle operations. For the AGM batteries, I think it's a total wash because the battery makeup is the same either way. What will often make your decision is the battery dimensions and what space you have to put them in.

[DaveMatthewsBand]

I have only just begun researching batteries for our 220RK so some of what I say might be gibberish.
At any rate, we are planning on doing a lot of boon-docking and we'll have a 3kw generator and 1 A/C unit.
I will be installing a few solar panels, charge controller, etc., at some point next year, but I wanted to go ahead and get
a descent sized battery bank setup in the forward storage compartment.
I think the 220RK comes with a single 12v generic battery which I'll probably donate to the dealership or keep in the truck as a backup.

Are there particular brands you recommend? I'd like to stick to AGMs. And from what I'm reading on these threads, running four 6v golf cart batteries seems to be the way to go. I don't care about weight, Buford could tow 2 of these trailers, I just want the least amount of maintenance and the most AH for a battery budget between $1,000-$1,500.

For about $1200 we could do 4 of these 6v 200AH each which (correct me if I'm wrong) give you a total of 400AH at 12v.
Because each pair is wired in series, which doubles the voltage but not the AH, then the 2 pair are wired in parallel which doubles the AH but not the voltage, correct?

I'd have to measure, but we might be able to fit 6 of these batteries in the cargo area up front which would yield... 600 AH at 12v?

https://www.batterystuff.com/batteries/t6v-agm.html


or 4 of these for under $1000?

https://www.amazon.com/UB62000-200AH...897240&sr=8-98

[Cate&Rob]

Some things to factor into your battery planning:
Even AGM batteries need to be in properly vented boxes.
AGM batteries can only be safely discharged to 50% (most inverters will shut off at this voltage anyway)
It takes a lot of generator run time to charge above about 80% (solar can definitely help with this)
So you should design your usage to run within 30% (80 <-> 50) of your nominal bank capacity.

Rob

[TucsonJim]

Mike Adams - Here's something else to consider with your 2600. I believe your hitch is set up like my Reflection 297RSTS. I put two group 27 batteries in the existing battery tray. Then I welded another battery tray just in front of the existing tray that holds another group 27 battery. Of course, since it's three batteries, I had to stick with 12V batteries wired in parallel. So I have three 12V Group 27 batteries rated at 90AH each. 90AH x 3 batteries = 270 AH bank. Running to no less than a 50% discharge state, I have 270AH x 50% = 135 amp hours of useable current if I start with the batteries charged to 100% which I can achieve with my solar array.

Jim

[johndeerefarmer]

I have only just begun researching batteries for our 220RK so some of what I say might be gibberish.
At any rate, we are planning on doing a lot of boon-docking and we'll have a 3kw generator and 1 A/C unit.
I will be installing a few solar panels, charge controller, etc., at some point next year, but I wanted to go ahead and get
a descent sized battery bank setup in the forward storage compartment.
I think the 220RK comes with a single 12v generic battery which I'll probably donate to the dealership or keep in the truck as a backup.

Are there particular brands you recommend? I'd like to stick to AGMs. And from what I'm reading on these threads, running four 6v golf cart batteries seems to be the way to go. I don't care about weight, Buford could tow 2 of these trailers, I just want the least amount of maintenance and the most AH for a battery budget between $1,000-$1,500.

For about $1200 we could do 4 of these 6v 200AH each which (correct me if I'm wrong) give you a total of 400AH at 12v.
Because each pair is wired in series, which doubles the voltage but not the AH, then the 2 pair are wired in parallel which doubles the AH but not the voltage, correct?

I'd have to measure, but we might be able to fit 6 of these batteries in the cargo area up front which would yield... 600 AH at 12v?

https://www.batterystuff.com/batteries/t6v-agm.html


or 4 of these for under $1000?

https://www.amazon.com/UB62000-200AH...897240&sr=8-98

Trojans are what most use and recommend.

You are correct on the configuration. Putting two 6V 200A in series yields 12V @ 200AH. Adding another set in parallel would give you 12V@400AH. Six total would give you 12V@600AH.

[DaveMatthewsBand]

Trojans are what most use and recommend.
You are correct on the configuration. Putting two 6V 200A in series yields 12V @ 200AH.
Adding another set in parallel would give you 12V@400AH. Six total would give you 12V@600AH.

Thanks Donald,

We've done more research and are now looking into using Lithium instead. Can we just replace the factory battery with 2 of these?

https://carolina-energy-distributors...ucts/12v-300ah

Or will we need to change out other items because these are Lithium?
We will probably end up adding a solar setup just not right away.
I understand we'll need other items for a solar package, but for now I'm just asking if we can simply replace the factory single 12v battery with 2 of those?
We'll still have the Honda 3000 to charge the batteries back up and when we want to run the A/C.