Choosing a Battery

Gary Potter · Post by **Gary Potter** » Mon Jul 29, 2019 3:47 pm

I am now the very proud owner of a second P30. My first has a single Interstate 12V. My latest acquisition has 2 6V Marine batteries wired in series. Is one 'really' better than the other? I've read deep cycle batteries (marine) are preferable to the high crank power of the automotive battery.

Since I don't anticipate long boondocking trips - does one over the other really make that much of a difference?

Post by **KYAvion** » Mon Jul 29, 2019 9:34 pm

Welcome back to the site. It’s been awhile.

Since it sounds like you will be on shore power most of the time, I’d just go with a cheap deep cycle 12v battery from Walmart.

RISK · Post by **RISK** » Mon Jul 29, 2019 10:21 pm

Hey Gary,

2? I’m not sure to be jealous or give you the number to a good shrink...

This is Not an area of expertise for me so allow me to share my numbskull level of knowledge here...

My 28M came with a pair of 12v deep cycle interstate batteries that are wired together, whether in series or parallel, I don’t know. I will say that I’m never without power, whether it be the lights, fans, fridge or pump. We haven’t really boondocked or anything but I’ve left it unplugged for awhile while between trips and this setup has held enough power for a few days of off and on usage.

Contrast that with the 1999 26’ class C I was given at one point (actually, the sale of this bought my Avion... but that’s another story.) that had a regular old heavy duty car battery wired in singular (I know that much) that would last mere minutes with any 12v load. Before I sold it I put a 12v deep cycle in it and everything ran better for longer.

Until LION batteries become more the norm both in scale and in technology, deep cycle batteries are the norm.

Ian

Post by **Razorback** » Tue Jul 30, 2019 7:59 am

I do not have any personal experience with 6V batteries, but I DO understand series and parallel wiring..../
With the 6V batteries, they need to be connected in series to get the 12V that your trailer needs. Picture a multi-cell flashlight where you stack the batteries in the handle positive to negative, positive to negative. Series connection multiplies the voltage and keeps the amp hours (capacity) the same...... 2 6V batteries make 12V, 3 would make 18V, etc.
You would use parallel connections if you had multiple 12V batteries that you wanted to install together..... Positive to positive, negative to negative. This will maintain 12V output, but doubles the amphours (capacity).

https://zbattery.com/Connecting-Batteri ... r-Parallel

Jason · Post by **Jason** » Tue Jul 30, 2019 9:39 am

My batteries get good workout when I switch the fridge to 12V for travel. The F150 can't push enough current to the trailer to run the fridge without the battery. The fridge draws ~18 amps and the truck pushes about 5 amps. That may not apply to you but its something to think about.

In my mind the main advantage 2 12V batteries have over 2 6V is that is something goes wrong with a cell you can just disconnect it and use the other battery. With 2 6V Batteries there is no redundancy. But with good maintenance 6V batteries with generally last longer due their thicker plates.

Here is a doc from Trojan that explains battery wiring better than I could https://www.trojanbattery.com/pdf/Troj ... sGuide.pdf

slowmover · Post by **slowmover** » Tue Aug 20, 2019 4:22 pm

ODYSSEY gets the nod for highest quality (look in a NEWELL or Prevost). Read specs. Make comparisons as you come down in price.

You MUST have 13-V to run the furnace fan. All else is optional. Use those two as the alpha/omega.

I “get it” about using Wally World. But what if you can’t get there (disaster). That’s the REAL dollar-value in an RV System. You’re on your own. And it works.

AVION Travel Trailers