Battery- bang for your buck

[AStravelers]

One thing I didn't see in Gary's article and I didn't see mentioned in other replies, is how far to discharge the batteries.

--  For longest battery life, don't discharge more than 25% (i.e 75% full)

--  Never discharge more than 50%.  Discharging more than 50% significantly reduces the life of the battery.

This means if you have a pair of golf cart batteries, you start with about 220AH's of battery.  So don't use more than 100AH and for best life don't don't used more than 50AH before charging.

Additionally, if you don't charge the battery to 100% full frequently, that would be every 7-10 days, (every 3-5 days would be better) the batteries will sulfate and you won't get as much capacity from them. 

This 100% charging issue is one big reason trying to charge batteries with a generator while boondocking or dry camping doesn't work well. 

Charging the batteries to 100% takes a long time, many hours.  The charge rate is very high at the beginning, but quickly tapers off to 10 amp, then 5, and lastly 3-0 amps over the last several hours. 

A well designed solar system, used for extensive boondocking or dry camping, will, on a sunny day, bring your batteries to 90% or better in just 2-3 hours and then the next 2-6 hours of sun will top them off to the at or very near the 100% mark. 

You might wonder just how do you know how many AH's you have used.  You buy and install a battery monitor like a Trimetric.  https://www.solar-electric.com/bogart-engineering-tm-2030-rv-battery-monitor.html  The battery monitor tracks and displays how many AH's that have been used and the % of battery life left. 

Without a battery monitor you are just shooting in the dark hoping you have not used to much of your capacity and not knowing just how much you have put back into the battery. 

[JayGlo]

We wanted to go with two 6V batteries and they wouldn't fit in the box.  After measuring, I was able to go from a size 24 to a size 31 @ 12V.  The cost difference was little and there is a lot more lead.  Next summer I hope to build a metal battery rack.  If you look around on YouTube you'll find a vid where a guy set up 6 Trojan batteries.  Wow a lot of power, but 450# and a thousand bucks worth!
Good luck.

[Ale_Brewer]

If I recall correctly, the Magnum inverter/charger you have (very nice unit), has circuitry included that will understand when the rig is plugged into shore or generator power vs unplugged and operate accordingly.  The tech the OP worked with, I suspect  was likely referring to the more basic and perhaps older models which were inverters only and in order to remain on when plugged into shore power, would require a relay to be wired between the inverter and the rigs power or for the converter to be switched off to prevent a conflict.

Gizmo is correct. That model inverter (very nice, indeed!) has a built-in transfer switch. An automatic transfer switch to be more specific, or ATS. This detects shore power and switches over to battery when no shore power is present. Shore power is the default selection. Your inverter must be on for the ATS to function. They used to say not to turn the inverter on when connected to shore power on the older stuff because it would "back feed" into the shore connection but you don't have to worry about that with your setup.

The battery that I would recommend the highest is the Fullriver 6V AGM. They are very nicely priced at just above $1/Ah and have a 7yr warranty.

[blowout100]

General RV is a mess. We have had nothing but issues there as well. Had to schedule an appointment to pick up unit. The day we went to pick up our unit they did not have the unit prepped, the battery was DOA, and things they were supposed to have fixed were not.

Its nothing but a sales factory there. They goal is to turn and burn as many units as they can, without any level of customer service after you sign the paper work.

Avoid at all cost!

[John From Detroit]

Which General RV was that (They have several stores)  My experience has been a bit mixed.  They screwed me at the time of sales it appears.. But that's another matter.

Only service complaints are the drip line on the Dometic Fridge.. But that one is almost funny.
And the Brake system install.. They messed up a piece of unneeded under dash trim, jamed the brake pedal arm and cost me a brake job WITH rotors... I tore the panel out and trashed it, As I said, not needed.
(It is supposed to be extended out via one of the vent holes in the outer fridge cover.. They did not do that.... Twice... And the 2nd time the technician assured me he ALWAYS did that (not).. Wixom store.

Some of their stores are diffidently better than others.