RV house batteries for dry camping?

[Tuesdak]

I inadvertently destroyed the house batteries on our last week long camping trip when we were in a shaded spot that prevented the 125w solar from working. Compounding the low charge problem was a Progressive Dynamics 9160 converter lacking the 5 cent Charge Wizard chip that retails for $26.00. Yeah restricted hours for generators: 3-4 hours a day at 13.X volts float charging... Short of it was running batteries way low and sulfation finished them off while I was scratching my head as to why they wouldn't charge much with (considerable) generator run time.

So an addition of the Charge controller will get 14.4v out of the converter and bring the batteries up to 80% in the AM and let solar do the rest. Larger wires to the batteries from the converter is on the to do list with new battery install. Without shade the solar does a good job of bringing the batteries back up on it's own with minimal genset run time.

The 5th wheel Arctic Fox RV is limited to Group 31 size batteries unless I relocate them. The biggest restriction is 10.5" height in the two stacked trays.

I am looking at a pair of 12v Trojan SCS225 for 260Ah @20hr rate $201.45 each. (This 260Ah would be more than enough for our needs in the RV.) 6v won't fit without relocation. And that's iffy as around the jacks on the sides of the generator compartment is the only area suitable for relocation. I could do four 6v T105's for the same cost as the two SCS225's. I might be able to go with taller 6v that have more capacity in that area. It's just the lack of room, relocation, etc. with the onboard Onan using the main area most would relocate too.

I can't find much about AGM's charging faster - and that would be the only value they would have for me. AGM's in Group 31 have a lot less capacity.

So my question would be is the advantage of going with two 6v deep cycle batteries worth the trouble of relocating the batteries? Any other battery recommendations over the SCS225?

 

[Killer223]

One of the best moves i ever did was upgrade to 6V batteries. Really it depends how you use the power, if you need gobs of it to run TV's then get the 12V, if however you need a long life for lights and low amps, get the 6V ones.
the second best thing i did was upgrade to this
https://www.progressivedyn.com/rv/power-converters/pd9200-series-rv-power-converters/
it's far better that the stock one i had.

125W solar isn't enough to top off the batteries if used much, maybe maintain them, but i wouldn't bet it's enough to recharge them every day with trailer use.

As for battery recommendations, i' not any help.

 

[TJJEEPER]

I do a LOT of dry camping and my rig is an energy hog. Best advice I ever got was from a Campground Host... "Don't permanently mount anything".

I carry 2 150 watt panels and about 50' of connector cord. This way I can place my panels in the full sun if the rig is in the shade. This way the only time I need to run the generator is if I need the AC.
I did a major upgrade to the full solar with a 3000 watt inverter that runs two circuits, the entertainment center (TV and Satellite) and Microwave. Also two 6 volt AGM monsters. No regrets.
I also have my satellite dish on a portable stand for the same reason. Just find a clear shot through the trees to "see" the sky I need to for reception.
A bit more setup and tear down time but totally worth it.

 

[Tuesdak]

What brand and kind of AGM 6 volt you using? Watched someone with portable solar on the same camping trip I killed the batteries on... Yeah that's a good idea. Yes, I can use more solar, but, the generator running for breakfast/dinner cooking side dishes plus solar for the day was doing ok in full sun even without the 14.4 higher voltage charge controller for the converter. Been toying with the idea of getting the microwave on an inverter. I will try out the 1500W unit I have around and see if it can handle it.

 

[K5IP]

Jdoremire, My 2000W inverter will handle the microwave, but it draws over 150A from the battery while doing so. Hardly worth it!

 

[Tuesdak]

Jdoremire, My 2000W inverter will handle the microwave, but it draws over 150A from the battery while doing so. Hardly worth it!

Good point. Other ways to cook (campfire, charcoal grill, propane stove) and if I need the microwave it's usually during generator hours. Just have to plan meals (lunch typically) around when Chef Mike isn't available.

 

[Vette Racer]

From what I read just go with the 2 12V batteries like the interstate at 105 AH +2 = 210AH in parallel, almost as much as two 6 volts with the larger AH of 232 unless you get the cheaper ones, put some more solar on and add the charge controller. Way easier than relocating batteries and still only using the two 6V, if relocating find a way to put 4 6Volts in, then you will have some battery power. JMO.

 

[Vette Racer]

From what I read just go with the 2 12V batteries like the interstate at 105 AH +2 = 210AH in parallel, almost as much as two 6 volts with the larger AH of 232 unless you get the cheaper ones, put some more solar on and add the charge controller. Way easier than relocating batteries and still only using the two 6V, if relocating find a way to put 4 6Volts in, then you will have some battery power. JMO. Also you could use the inverter for a microwave but unless you have more solar and you don't use it for anything other than a minute or less it doesn't make sense, use the genset for that. I have a 2000 watt inverter and it will max out running the micro, too much amps used for my liking.

 

[Vette Racer]

Well shucks, I added to the first post, it added a second and can't delete it so forgive me for screwing this up. Need a delete the post key!

 

[Tuesdak]

I found I can put just about as big a battery as I want in the compartments to the right and left of the genset where the jacks are. The compartments are already vented out the bottom. Just run some wire and add hold downs.

I have a 50AH load overnight in addition to the regular RV load. (cpap by it's chart load/settings estimation)

So I am looking at:
Trojan T105 6v $110 each relocated 225 AH.
Trojan SCS225 12v $201.43 each OEM location 260Ah.
Trojan T145 6v $211.15 each relocated 260AH.
Lifeline GPL-4ct AGM 6v $299.89 each OEM location 220 AH.

6 volts require two 12v battery cores ($15 core charge) each.

Looks like it's hard to compete with the super mass produced T105 Golf Cart battery in the standard capacity.

 

[Killer223]

Agreed, I have the golf cart batteries, they will let you draw them down much lower than the normal deep cycle 12v. When out hunting I can go a week on batteries alone.
I tried the 12v route, had 4x12v, then got serious and got 2x6v and so glad I did.

 

[Joseph Donnelly]

I'd get two Odyssey Extreme batteries.

 

[TJJEEPER]

What brand and kind of AGM 6 volt you using? Watched someone with portable solar on the same camping trip I killed the batteries on... Yeah that's a good idea. Yes, I can use more solar, but, the generator running for breakfast/dinner cooking side dishes plus solar for the day was doing ok in full sun even without the 14.4 higher voltage charge controller for the converter. Been toying with the idea of getting the microwave on an inverter. I will try out the 1500W unit I have around and see if it can handle it.

Sorry, missed this. They are 260 Amp Hour US Battery. The place I bought them sold a bunch of different brands including Trojan. Since I was building the "system" they gave me US Batteries tech email. They were helpful in choosing the various parts of the charging system. I wound up with about 40 more amp hours than I had from the factory.
This weekend I was out dry camping again. I would see 14 amps up to 14.7 volts for the bulk charge. The charging cycle matches what US Battery said I should be doing. It'll hold the 14+ volts for a bit then the amperage slowly goes down until it reaches the roughly 4 amp range then the voltage drops slowly to 13.8 and holds there at 1 to 4 amps depending on what's running. With the size of the solar panels I can charge the batteries to full charge (from 11.9 volts) back to full charge in about 4 hours of full sun.

I could have put larger batteries in but it was a compromise between size-space and weight. As it was I had to reinforce the battery area. As a side note, I had the rig on consignment for almost a year before we decided to keep it. The dealer let the batteries go flat. I was major ******. Had to jump start the generator to pull in the slideouts and jacks. Brought it back home expecting the worst. So far, in a year, no ill affects.

When you're looking make sure you take the weight into consideration. It's all I can do to place and remove the batteries due to the 5th wheel overhang over the battery compartment. In my mid 60's when I installed them it took some engineering to put them in without blowing out my back.

 

[K5IP]

I have room for only one battery. I use an interstate 29. The point I should make is that at age 79 I have a hard time lifting the thing into my trailer. I always take it out during winter and store it in my basement with a trickle charger on it. At 7 years old I think I have my money's worth out of it, but If I had room for two 6v golf cart batteries I' be there in a minute.
Rog

 

[barkerdl]

If you are interested in longevity, consider the Trojan T-105. I put a set of them in my Montana in 2010 and they still load test fine and use very little water.

Dennis

 

[Tuesdak]

I went with the Lifeline GPL-4ct AGM 6v and found I still have to do some mods to fit the OEM location or go with an alternate location. Off season project... The battery fits the trays, but, the hold downs are on the inside of the tray and no room. I missed the support under the top tray that interferes with the last 2" of the bottom battery and the top battery will hit the edge of the battery compartment door.

I also added a Bogart engineering TM-2030-RV to see how much I use out of and charge into the batteries combined with the TM-2030 solar controller with temp sensor. (The extreme heat out here kills batteries quickly so I don't expect as long of life as others get.) Hopefully this will make the 12v system less worry and reduce genset run time. Plan is to run the genset during the 2 hour window in the AM and let the slower solar top them off.

Interesting thing about just two 6v batteries is the full charger current goes through them in the bulk charge phase so they are not splitting the 60A like two 12v's would from the converter. The single string 6v batteries don't have the one works harder than the other due to wire distance etc like the 12v's do.

 

[RBridenbaugh]

One of the nice things about AGM batteries is that they can be charged in all orientations except inverted (can be discharged in all positions) so with a little creative positioning / orienting they may fit your existing compartment.

Since you don't have to add water or perform routine maintenance, you don't really need the trays (frees up more room). Since they don't leak acid, you can hold them in place with nylon rachet straps (normally dissolved by battery acid) and glued/screwed lips inside the compartment to prevent shifting.

Two Lifeline GPL-4CT batteries fit into the original compartment of my truck camper, designed for one Group 31 battery. No room for trays. Compartment door width made it almost impossible to get my hands inside and lift the first 69 lbs battery over the 1/2" lip of the compartment door, when I needed to remove it. Solution was to get a mini suction cup dent puller and use it to attach to the end or sides of the battery to remove it from the compartment.

When hooked to a good charging system these sealed AGM batteries are very unlikely to vent hydrogen gas while charging, so while a possibility, it is not very probable. When I needed more capacity for winter camping I mounted a second pair (440 Ah total), inside under the dinnette seat. I was comfortable with the risk.

AGM batteries have lower internal resistance, thus charge faster, plus they have a lower self discharge rate. More Ah capacity if they are kept inside vs. in an unheated compartment during winter camping. Also, in a cold location a discharged battery's electolyte will freeze and destroy a flooded battery, but not an AGM.

Wiring from my truck alternator back / forth to the camper and inside the camper was changed to 2AWG, to allow more current to charge the larger battery bank, without having voltage drop issues. Recharges the batteries and runs other 12 VDC devices while driving.

 

[Tuesdak]

Modify 2003 Arctic Fox 27-5L to fit 2 Lifeline GPL-4CT AGM 6v battery

I don't see any pictures of doing this online other than battery boxes elsewhere. That elsewhere has a generator in the way for mine.

I missed the supports for the upper battery tray in the way when measuring.

So overview of battery compartment (Did not mount batteries like this.):

Supports in the way:

Cut out with angle grinder:

Battery tray modification (Lift the front of the tray up and it will come out.)

Won't clear battery hold downs on side:

New Bogart Engineering SC-2030 Solar Controller:

Current Shunt:

Wiring following the plumbing:

New TM 2030-RV:

Old "dumb" Solar Controller (Above where microwave used to be. New bigger size microwave located elsewhere now as they don't sell same smaller size ones anymore.):

I wound up with the batteries mounted upright in the trays. I wrapped the terminals with silicone tape. The only tight fit is the negative terminal on the bottom that can interfere with some of the top support that didn't get ground off - no big deal as they are at the same potential. I had to grind more off from the pictures as I measured and cut for sideways mount first.

 

[Tuesdak]

Finished Battery compartment. I pushed the top battery as far in as possible due to the reduced support I cut out.

Tight fit. Note battery temp sensor for the solar controller is on the negative terminal in there somewhere...

Chief Mike's new home. The Original Owners had a TV there.

 

[MichaelOverfield]

Quite the modification! I have had good luck with cheap Walmart Group 29 deep cycles. I run a pair and do use the microwave on the inverter for cooking. These are what I use: https://www.walmart.com/ip/Everstart-Maxx-Lead-Acid-Marine-RV-Battery-Group-29dc/131118029

I got 10 and 12 years of life from the last set of these Walmart cheapo batteries (first I went to one then added a second couple years later). My original location would only take a Group 24, so I got out the welder, and now it will take the Group 29 (or bigger)!

For your upper battery mount, having cut out that structural steel, I'd recommend a cross brace to go across (side to side looking, forward/aft on trailer), then down at an angle (clear the lower battery) and attach to the frame.

The mount is currently holding well, in a static load condition, but once you get moving down the road, large bumps and shock loads are going to be very high stress loads on that bracket, at a very high stress level, and RV OEMs to not have the best welds (I had to do extensive re-work on mine and it has structural cracking). I'd be worried you see a weld/crack/fatigue failure on that top mount.. causing to to short out the battery on the lower mount (wear through your insulated connectors). That would make for a bad camping trip.