Battery confusion

DougWW

I've read so much about batteries lately that it is merging into one large D-cell. So I will ask those with experience for their thoughts.

The situation:
T@B 320 S Boondock, considering the 2021 model with built in solar. We have a membership with camping privileges so our projected use will be 3-4 day stretches throughout camping season, with periodic longer trips as destinations open up. We estimate 90% of use will be boon docking and no electrical connections. We don't own an APU.

The question:
Should we upgrade from the stock 12volt acid-filled battery at purchase?

Lithium is not a candidate at this point in time. We've got 3 choices:

1. Stick with the stock battery. Immediate cost: $0

2. Add a second 12 volt in parallel. Immediate cost: $200

3. Change to 2 6volt batteries in series. Immediate cost: $540

Right now I'm leaning toward the 6V option, though that would admittedly be a bit of a financial strain.

How do the 6V compare to double 12V options compare in the field? I've found little online to compare these two, and the dealer seems to like the 2 12s best. I understand there may be some charging issues as the batteries don't "equalize" but I don't think I understand that relationship.

Thanks for your help.

Sharon_is_SAM

You don't say where you will camp (sun saturated or sun phobic), but there are plenty of people who boondock for a few days with no more than a 100 amphr lead acid or AGM battery with solar.  For only a 3-4 day stretch, a higher battery capacity will get you a longer period without sun, but it all depends on how much you use on a daily basis.  We elected to have a 150 amphr AGM installed.  We just don't use that much power and we have never discharged it even close to half.  So, if you want to cover ALL of your bases, get as much capacity as you can afford, but, you may not need it.  Like they say - it depends...

Why not have the dealer arrange to have a battery platform that will hold 2 6 volt batteries and just start out with the stock battery.  You can always easily exchange the batteries once you have a platform to hold them.  Besides, it is tradition on the forum to ruin your first battery, so do it as cheaply as possible.

pthomas745

Which fridge do you have?  Most owners of the new trailers are getting every efficient fridges, with batteries that don't have enough capacity to last a whole day, so good solar is crucial.  Bigger battery capacity is crucial.

Here is a rundown on the difference in dual 6v compared to dual 12v. 

https://www.rvhometown.com/6-volt-vs-12-volt-rv-batteries/

CharlieRN

Sharon_is_SAM said:

. . .  Besides, it is tradition on the forum to ruin your first battery, so do it as cheaply as possible.

I'm pretty sure we will uphold this tradition.

After doing some research, we arranged with the dealer to install dual 6v batteries at delivery of our T@B 320 BD. We've since changed back to the stock Grp 24 80 amp hr 12v battery for a few reasons. It's likely that the stock battery will not be sufficient, but taking delivery with it gives us the least-cost way to experiment.

An additional reason was finding out that most of the battery manufacturers ratings are not accurate. There is also testing information from various source indicating that the less expensive flooded cell batteries, though also not meeting manufacturers specs, often outperform their more costly gel and AGM brethren. The on-line testing documenting this that I've seen seems to be accurate but since it's sponsored, some  skepticism is warranted. Still it's worth checking some of the youtube videos on the subject before investing.

We hope to get our T@B in the next few weeks (we ordered back in August) and will start the experimenting then. I suspect that we will eventually wind up with extra solar panels (probably of the suitcase type), a different battery type (LiFEPO4 is undoubtedly the best in terms of performance & life-cycle, but the steep cost is a big hurdle) and a DC-DC charger to optimize both charging and battery life. We will be taking things slowly though.