Solar - RV-Dreams Community Forum

Den-Bev · RV-Dreams Family Member

Solar

Lonney Wade · RV-Dreams Family Member

I would not go below 12.2 volts that is (about) 50% down in charge, at that voltage or lower, the longer the batteries stay at that low voltage the more damage you will do to the batteries or in other words, sulfation occurs when a lead acid battery is deprived of a full charge.
This shortens the life of the battery.
Now if you take the batteries only 25% down or 12.4 volts from a full charge, then charge them back up, your batteries will live a longer life.
Now depends on what battery you have, Flooded cell battery, Gel battery or AGM battery here is a chart for a 12 volt system, even if it's (2) 6 volt batteries put together in series it's still 12 volts.

Lonney

Here is a chart of battery voltage.
Remember these numbers when charging
your batteries.

State of Charge	Sealed or Flooded Lead Acid	Gel battery	AGM battery
100%	12.70+	12.85+	12.80+
75%	12.40	12.65	12.60
50%	12.20	12.35	12.30
25%	12.00	12.00	12.00
0%	11.80	11.80	11.80

Jack Mayer · RV-Dreams Family Member

The voltage chart Lonney published is a good start, and better than nothing. But it is not very accurate under most RVing conditions. An improvement on the voltage using voltage to determine battery state-of-charge is a cumulative ampmeter battery monitor like the Trimetric series from Bogart. If you boondock much then it is worth the (under) $200 that it costs. Look at the Trimetric RV2025 or 2030.

Den-Bev · RV-Dreams Family Member

I have flooded battery's also have ME-RC and the TriStar TS-RM-2 when I can learn how to read it.
Den.

01zeosix · RV-Dreams Family Member

Den-Bev wrote:
I have flooded battery's also have ME-RC and the TriStar TS-RM-2 when I can learn how to read it.
Den.

http://www.morningstarcorp.com/products/tristar-remote-meter-2/

Hope this helps. Sending from my "smart" phone. Might be an oxymoron.

TRAILERKING · RV-Dreams Family Member

Jack is that Trimetric to be used with an inverter or is it for control of Solar panels?

01zeosix · RV-Dreams Family Member

TRAILERKING wrote:
Jack is that Trimetric to be used with an inverter or is it for control of Solar panels?

The Trimetric is a stand alone battery monitor. Battery monitoring and a good understanding of Watt you're using (if you forgive the pun) is fundamental to energy system management. A Trimetric monitor and something like a "Kill A Watt" meter are a great place to start. Other tools in your energy arsenal is surfing to sites like Jacks and asking questions.

Hope this helps....

Jack Mayer · RV-Dreams Family Member

zeosix answered the Trimetric question....let me add a little.

If you phase in an off-grid system probably the first thing to do is to expand your battery bank. As part of that effort you should ALWAYS put in a battery monitor. That is the only way you can accurately monitor your power usage and protect your battery bank. Every RV that does more than just a little boondocking needs some sort of accurate battery monitor. I happen to think the Trimetrics are the best out there for the $$.

Bill and Linda · RV-Dreams Family Member

Jack Mayer wrote:
Every RV that does more than just a little boondocking needs some sort of accurate battery monitor. I happen to think the Trimetrics are the best out there for the $$.

X 2 This is just so simple and easy to read - and it works. Even has a percentage meter so you don't even have to remember anything once the device is set up. Using battery voltage, as Jack said, is better than nothing. But you can ruin a battery bank in no time just looking at voltage, IMO.

Den-Bev · RV-Dreams Family Member

So now when on Solar should we use a 110v fan or try to find a 12v one?
Den.

LarryW21 · RV-Dreams Family Member

Trojan says my T-125s will get about 1,250 to 1,500 cycles if I discharge to 50%...about 12.25 volts.