Not enough battery capacity with 4 6V batteries

[Bee950]

The more I learn about powering a house on 12V, the more I learn my MH came from the factory with enough capacity to get you from campground to campground.

I have four 6V house batteries and i believe they are 115 amp each. That should give me 230AH total capacity. Multiply that times .6 and you end up with 138 usable amps. The 21 halogen lights in my coach draw around 43 amps for just the lighting if everything is on. (which isnt likely but you get the point) Its a power hungry pig!

I plan to use my MH for business starting in March. I will be on the road and staying in places not anywhere near electricity unless its from a generator, and some of these events are 10 days long.

I am giving a serious look at Solar and also upgrading the batteries to 200amp Trojans. One thing i read today is the Magnum Inverter/charger I have can be programmed to up the battery charge voltage to 14.8 volts. Default is 14.4, so I dont think they are ever getting 100 percent. Is this recommended?

Suggestions? I have until March to come up with a solution

[old bullfrog]

Hello Bee,

You might take a look at the following link for what appears to be very good info. I am studying the same issue concerning batteries and solar power. Handy Bob is living the full time life and has put much time in documenting his experience for the rest of us to learn from.

His link "The RV Battery Charging Puzzle" is: The RV Battery Charging Puzzle « HandyBob's Blog

Hope this helps in you decision. I have printed the entire "puzzle" so I can reference it and make my notes on it. Thanks to Handy Bob!

[Bee950]

I have read it twice already. I am just searching for all the options before I decide on whats best. Either way, I need to do something. I am afraid their is no easy answer, but it doesnt hurt to ask..

The article talks about a lot of things, but I already have a charge controller that allows me to push 14.8 volts, so I am wondering if modifying or doing something simple to the existing system would work.

[Mr_D]

OP, I'm surprised that your battery bank is that small! We have 4 -2200's which gives about 230 Amp hours before we're down to 50%. Ours are over 9½ years old now and still doing OK, but I'm expecting to replace them next year.

[kellylipp]

I'll have more to say on this in a month or so. I am heading to AZ to pick up two solar panels and the rest of the equipment to install solar on my rig. I've read everything to read and I guess drank the kook-aid as well. I've designed a 380W system which I figure will be enough for my needs.

It seems your needs will be a bit larger but that should only mean additional panels which should be fine on your rig. I figure my system will cost about $1200 all said and done. Yours could grow from mine just by adding two more panels bringing your cost to $1900 or so. 2000W Honda generator costs around $1000 plus gas and upkeep.

I've attached a diagram of the system I am installing. The Tristar charge controller I am using will handle at least one more panel. Two more one should probably jump up to the 60 amp version. No need to use the higher priced MPPT model if you are willing to use the low voltage panels (which are harder to come by...).

[BryanL]

Lead acid batteries have a usable energy density of about 12 watt hours per pound. The typical RV battery weights about 65 pounds so a 4 battery bank has about 3 kilowatt hours of usable energy capacity.

The typical household energy consumption is about 30 to 60 kWh per day. (US DoE)

That means your RV has energy storage that is about a tenth that of the typical daily household energy use and the usual rule of thumb is that the RV bank should handle 2 or 3 days.

There are some that have blown their gaskets when I offered this comparison but it does show why battery capacity in an RV is quite limited when compared to what people are used to.

As for Handy Bob and the solar dreams, they are entertaining but you really need to watch out for context and proper comparison. There aren't any magic bullets. They deal with small percentages where the OP issue is about orders of magnitude.

[YC1]

If you have golf cart size batteries you probably have 440 amps. As mentioned no way do you need all the halogen lights on. If I had that many they would be changed to LED's which I have changed several already. The halogens above the bed for reading would burn you if you accidently touched them. That was dumb. Simple change to Halogen. I haven't made a huge effort on the halogens along the inside because I have flouresents down the middle and they are conservative for the amount of light given. That said the nice little generator uses little fuel when keeping up with those loads. If the tv or radio is on the generator is barely audible. It will be almost silent after I do some more sound dampening.

Solar is great but expensive and unreliable at times. Shade, winter etc can reduce the output a lot. The diesel generator is very quiet and fuel efficient and you can heat your water too. I even run my electric fireplace.

The generator is quiet but my current fixation is to make it almost silent. I modified the air intake and the noise dropped a lot Hopefully I can get it as quiet as a purring kitten.

[DAN L]

Originally Posted by Bee950

The more I learn about powering a house on 12V, the more I learn my MH came from the factory with enough capacity to get you from campground to campground.

I have four 6V house batteries and i believe they are 115 amp each. That should give me 230AH total capacity. Multiply that times .6 and you end up with 138 usable amps. The 21 halogen lights in my coach draw around 43 amps for just the lighting if everything is on. (which isnt likely but you get the point) Its a power hungry pig!

I plan to use my MH for business starting in March. I will be on the road and staying in places not anywhere near electricity unless its from a generator, and some of these events are 10 days long.

I am giving a serious look at Solar and also upgrading the batteries to 200amp Trojans. One thing i read today is the Magnum Inverter/charger I have can be programmed to up the battery charge voltage to 14.8 volts. Default is 14.4, so I dont think they are ever getting 100 percent. Is this recommended?

Suggestions? I have until March to come up with a solution

I still like my 5 year old lifeline gpl6ct 300 ah agm batteries. i had room for 2 when i laid them on their sides. i got them from bd batteries online.
I also have a jirah led strip kit installed in my kitchen fluorescent fixture. i plan to install 3 more of them in the ceiling fixtures. i have not found a led light to replace 12v incandescent lamps that i like yet. i like warm white lamps. the lights that i have tried have been cool white and not bright enough.

Lifeline GPL-6CT Battery

welcome to jclampstand.com!

[fillbert]

With regards to the florescent light strips...did you did you replace both tubes with one strip or two within the fixture??

[BCooke]

Optronics Inc. Has some nice puck lights that give off ~200 lumen. And draws half the current of a halogen.

[Bee950]

Thanks for the info on lifeline batteries. The 300 amp ones would be the way to go. Based on those I should be able to run 10 hours at 30 AH draw.

[wa8yxm]

if they are 115 AH each those are small batteries (Perhaps optimas?) The standard Golf Car battery (GC-2 size) such as the Interstate U-2200 or the US US-2200 or the Trojan T-105 is 220 amp hours give a very few (single digit) amp hours variance brand to brand.

however... This remains.. If your batteries are not enough. add more. that's the only answer.

[camper8251]

Wow, you are not kidding about the power usage! Check powerstride batteries. They sell lifeline and IMO are the best bang for the buck. You definitely need to change those halogen and Flourescents out to LED. Super easy to do and you will save tons in AMPS.

[bluepill]

Re: Charging voltage. With "Flooded" batteries (as opposed to AGM), 14.4 volts is considered maximum "normal" charging voltage. 14.8 volts is considered "equalizing" voltage, which should not be used for every charging cycle.