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I have two size 27 deep cycle batteries wired in parallel for my TT. My TT has the basic combo tank and battery column of lights level monitor. I would really prefer a number read out and not an idiot light set up like I have now. I wish to monitor my batteries and prevent them from being discharged bellow 50% to maximize their usable life. Who makes a decent monitor that can be wall mounted in my TT. What do you recommend??

Thank you all in advance for your replies.
Hi Brad,

I prefer to just use a volt meter.

Amp-hour counters do exist, but are almost certain to be "out" on their "guess" about the state of charge of the battery bank.

Why? Well, because state of charge is affected by temperature, age, chemistry, and other factors. All of the amp-hour counters (such as the popular trimetric) require the user to enter the total capacity in amp-hours. But--that's a moving target.

There are some voltage monitors that do have "alarms". They are fairly inexpensive.

Cost for solar panels is down to $1.35 per watt at the moment. Spend the monitor money there instead.

Almost all solar system users end up with exceptional battery bank life spans.

Are the batteries currently wired in a "balanced" manner?

"Are the batteries currently wired in a "balanced" manner?"

Hi Don,
Thank you for the reply. I guess I will start by aswering your question with another question. What do you mean by wired in a "balanced" manner?
I have batteries A and B wired in parallel (A+ to B+) and (A- to B-) + lead from TT is wired to A+ terminal and - TT lead is connected to the B- terminal. I think this is what you are refering to.

Solar is out right now due to $$$ and I think lack of roof space, as my TT is a FunFinder X 189FDS. Not very big by any standards.
I am trying to optimize my situation as best I can for boondocking and using my amateur radio while parked. I hope this helps you see where I am comming from.
Thank you very much.
Hi Brad,

If dollars are a concern get a $15.00 volt meter from walmart and plug it into a cigarette lighter outlet.

Your trailer is 18 feet long and 7 feet wide. I'm sure space could be found for say 120 watts of solar.

This is what is balanced and best for twin twelve volt batteries.

IPB Image

As it often doesn't cost a dime more to do this, I think it is worth the trouble.

If you wish to understand the "why" surf here:

correctly interconnecting multiple batteries
I'm no mechanic but from what I can recall from my boating days, that is why deep cycle batteries are used for temporary power. Their much thicker lead plates can handle the drain/recharge cycle many many more times then standard batteries. I would think that taking them down to below 50% won't really hurt them, especially if you are obviously aware of the amount of drain, or hours, you have run them.
Hi vincee,

Every cycle causes some permanent erosion of the positive plate. Going below 50% reduces the number of cycles and is not recommended for flooded deep cycle batteries.
John Blue
Same with golf cart batteries, the more you charge the better. If you charge each week in my case you will have more cycle counts. If you charge each month you will have far less cycle counts before batteries stop working. I also use an electronic desulfator device to remove the sulfate crystals (white snow) on plates. We get around 7 to 8 years on a set of batteries.
Hey Pianotuna,

Thanks for the education on batteries. As I said, I'm no mechanic. Just wondering, why the original post does not consider a small generator. I know going with a low noise Honda can be pricey, but there are low cost models (aka China) out there too that should take care of the battery drain problem all together, just like campers that have RV's with on-board gensets.
Hi vincee,

Recharging with a generator may be the least cost effective way to maintain a battery bank. One still needs to know the state of charge.
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