2 Batteries or 4

[PokerDealer]

I up graded to two 6 volt (Trojan T105's) and have been pleased with the extra amp hours. I have two questions; is 4 better than two, and second question, If I put a metal battery box on the front end of my trailer, will the extra width for 4 batteries cause a restriction in turning or tongue weight? I'm having a hard time getting into my battery cases, to take a voltage reading, (each battery is strapped into it's own box and I have a sm steel cable securing the boxes to the frame) so I'll know when to charge them. Putting them in a tongue mounted battery box will solve two problems, theft and access. If I put in 4 does the extra power create it's own problems.

[Makoto]

If you have 2 six volt batteries and one goes bad for some reason, you would have NO DC battery power. If you have 4 six volt batteries and one goes bad, you can still run off of two of them. In addition, with 4 six volts you have double the power capacity/run time.


2011, 8314BSS Rockwood Signature Ultralite & 2005 Dodge Ram 2500, Quad-Cab, 5.9L Diesel, 4WD, 3.73
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[rsdata]

You could run two banks of two batteries per bank separately... or hook the banks in parallel for twice the amount of power and longevity...

are you planning on long boondocking stints without any recharge capability?

I would rather spend money on a genset (to recharge at camp in the woods) and two batteries... letting discharged batteries set for any length of time (several days or longer) in a discharged state decreases their life... or adding some solar cell capacity to recharge...

also putting that much weight on your tongue (4 batteries and a metal box) might give you towing issues with too much tongue weight on your TV... unless you have a truck TV...

batteries don't generally go bad in normal use... picking up another pair as a spare set makes no sense, as the other "good" battery could not be used at all with the spare pair... if you want a spare then you only need one spare battery... but still is not necessary IMO...

[Bluepill]

Doubling the number of amp hours means you will double the time required to charge if you run the 4 down to the same level as you now do with your 2. Example: you currently run your 2 down to 50% each night and then recharge. You run the 4 down to 50% in 2 days and then recharge.


My point is that you may want to upgrade your converter/charger also, depending on your usage patterns.

[Klipstr]

If you need that many amp hours before you charge then yes, four is better than two. Before doing any of this I would seriously consider what my loads are and plan accordingly. In most cases lighting is the largest consumer of 12V power in an RV. Replacing your incandescent bulbs with LEDs will reduce that consumption by a factor of 10. I can run all of my lights for the entire evening and will only show a 5% reduction in my battery SOC.

You ask how I know this? I have a Trimetric meter monitoring my battery bank (and my solar output and charing for that matter).

Bluepill is correct: if you double the battery you double your charging requirements assuming you use double the power.

While I have nothing against generators, I don't want to hear them when I'm camping. For long boondocking, then, I needed an alternative. That option was correctly designed and installed solar. This is not as hard as it might seem.

The only thing I'm selling here is the concept. Tons of info and help at my blog shown below.

[PokerDealer]

Thank you guys, I was going to start at the converter/charger but identified it as a decent 3 stage 50 amp converter. I took the batteries down to 12.2 and just plugged my 30 amp cord into a 25ft. extension cord and then the house and left it overnight. I expected it to take 12 to 16 hours to get to a full charge through the converter. At 12 hours it was at 13.7 amp and 93%. I opened up the battery cases and put my charger directly on the batteries. It took about an hour and a half to bring them back to 100 %. I did the same thing again but the batteries were only down to 12.4 and pretty much the same thing happened. I was concerned that the converter need to be replaced or I was going to add solar, neither was necessary. If I do buy an aluminum box for the batteries it will be a lot easier to access then. I was just thinking that if I get a box for 2, I'm stuck with two. If, I get a box for 4 and it's not in the was of turning. I'd be thinking ahead. Don't have to get the batteries now. If I got solar or a genset, I'm looking at 2k to 4k. If I get the box and batteries I'm in 200 to 500. My tv is an 05 ram 1500 SLT 4x4. It tows really nice. The TT is only 25ft and 7K lbs

[PokerDealer]

LED's and low amp fans are in the future as well as a Trimetric 2030. I'm also looking around for a Mr. Heater. It seems my batteries can't run the heater very long on those cool nights. Thanks again for the help I'm convinced I don't need a genset to be gone a week, maybe two when I finish setting it up....

[Klipstr]

If you google "HandyBob" he has a page on brick style propane heaters. If you spend a lot of winter in an RV these make a ton of sense. Radiant/convective heat with no fan. His site is another great place to start when considering solar.