After reading all the comments to my last battery related post, I am leaning towards replacing the single group 27 12V of unknown vintage. I would like to go with 2 6v T-105s, but I am not certain if they will fit in the space provided. There is an angle iron tray behind the propane tanks that is 24" wide by 7-1/2 inches deep. The problem I have is with the height. The trailer angles forward to a blunt nose and at the very back there is only ~9 1/2" before meeting the trailer. So, what I need to know is if the dimensions for battery heights includes the post or not. If not, then I may have a problem wedging them into the tray. If it does, then the back of the battery case should be about 1/2" shorter and it should fit. Thanks in advance for the assist.

11.15 inches from bottom of battery to the top of the terminal. Max terminal height from top of battery to top of terminal is 1.5 inches.

Well, that ain't gonna work. Way too tall! Anybody got any suggestions on alternatives, besides just getting a new 12V replacement (last resort)

I have GC-2's I got from Napa (220 AH / 6V) and the height on those are 10.25 inches from bottom of battery to the top of the terminal. The terminals are 1.25 inches from top of battery to top of terminal.

It sounds like the battery tray is sized for two group 27 batteries.If you put two group 27 AGM"s in there like Lifeline, Trojan, VMax, you'd have about a 200 AH battery bank.:):)

24" x 7.5" x 9.5" tallLooks like you are not going to be able to stuff much AH capacity there as it is not wide enough for 2 27's side by side, not tall enough for GC-2(t-105), or even a single t-1275.You can't get a flooded/wet true deep cycle battery in the group 27 or 31 size format. Trojan makes both these sizes and they are just marine batteries and they are rated for only half the total cycles of a T-105. That said they are likely the best flooded group27 or 31 'deep cycle' battery available. With Crown, EastpennDeka and USbattery also making these sizes and being similar in weight and deep cycle durability.But any other wet/flooded group27 or 31 like a wally world marine battery will not last as long as the above brands, but since they are significantly cheaper cycles per $ might be the same, especially if you can't really treat them well with prompt and full recharges.IF you can handle the price tags of AGM, and understand they require higher amp recharge rates every so often and are more demanding of full recharges more often, then you can get a good deep cycle battery in there, such as a Lifeline.You could get 2 group 24s Lifelines in there side by side for 160Ah totalhttp://www.lifelinebatteries.com/marineflyer.php?id=1YOu might be able to fit 2 Lifeline GPL-6ct on their sides for 220 Ah total.http://www.lifelinebatteries.com/marineflyer.php?id=15Keep in mind Lifeline suggest a minimum 20% recharge rate when these batteries are cycled to or below 50%, and they want you to achieve and then hold 14.2 to 14.4 volts until amps taper to 0.5% of total capacity(20hr rate) at 77F.Achieve this and these batteries will serve you very well. Do not achieve this recharge regimen and you might as well just get flooded group 24's in parallel and beat them up and just replace them more often. AGMs do not make for good wet replacements unless their charging parameters can be met by the existing charging sources, or the charging sources can be tailored to the AGMs needsAlways a good read:http://www.lifelinebatteries.com/manual.pdfScroll down to page 20 for charging instructions.I am getting good service from a group 27 Northstar AGM, but like Lifeline AGMs, it requires high amp recharge rates and being fully charged often. Slower recharge rates to full from a deep cycle, and the capacity walks down. Get to only 95% daily, and the capacity walks down quickly too. Luckily one or two high amp recharges from the most depleted state to bursting full restores performance, so far anyway.NorthStar AGM's are sold as X2power at Batteries+. They add another year to Northstar's 4 year full replacement warranty.Odyssey is another high quality AGM but they recommend 40% recharge rates when deeply cycled. 40 amps per 100AH of capacity. Kind of unrealistic to plan for this much initial charging amperage in an RV with a lot of capacity. The high amp rate need not be met every deep cycle, but it is a requirement every so many cycles.There are AGM's that cost less and have a 30% maximum recharge rate, such as the Vmaxtanks and Deka intimidator and Universal battery, but these do not have the super low self discharge and the super high CCA ratings of the NS/Odyssey AGM's which might be beneficial under high inverter loads, if those are factors in your intended usageSo find your compromise since t-105s wont fit.

T-105s - Will they fit? | Good Sam Community

MEXICOWANDERER
Explorer
Jan 25, 2016
You haven't indicated just how BAD you want or need added battery capacity. Some of the alternatives are rather pricey. About six-hundred-dollars pricey for a pair of AGM batteries. A lot of advantages but your wallet will hate you.
Almot
Explorer III
Jan 25, 2016
pnichols wrote:
several companies offer 12V deep cycle dry acid batteries.

They are normally called AGM. More expensive than wets.
2 12V group 31 (100-110 AH) should fit, either wet or AGM.
Decent AGM like Penn/Deka start from $220-230 per 100 AH, and decent wet - from $160-180.
marquette
Explorer
Jan 25, 2016
Outside dimensions of the Century Plastic battery box for 2 GC batteries is: 22 3/8 x 8 1/2 x 13.
pnichols
Explorer II
Jan 25, 2016
Two 12V deep cycle batteries should about equal a couple of 6V golf cart batteries.

Trojan offers 12V deep cycle liquid acid batteries and several companies offer 12V deep cycle dry acid batteries. I use a couple of 12V deep cycle Group 31 batteries because they are not too tall to fit into our motorhome's battery box. 6V golf cart batteries are too tall for our space. Our two 12V batteries provide a total of 230 amp hours of capacity.
Almot
Explorer III
Jan 25, 2016
TBammer wrote:
I think the twin group 24s is the answer.

My tray is exactly like yours, 2 rails on the A-frame, and angled front wall encroaching this space. Three 12V batteries will fit there with one or two inches to spare. Though 3 separate battery boxes might not fit, and it's nearly impossible to find one long box for 3 batts that would fit into those rails either.

Roy is right, you can bolt an oversized box onto the A-frame and place 3 or 4 batteries lengthwise. But, if 2 batts is enough for you, then get 2.
RoyB
Explorer II
Jan 24, 2016
OH I was thinking a tray inside an compartment.

What I did on my OFF-ROAD POPUP trailer is mounted some right angle sections that extend out over the trailer tongue. I was extended out on both sides of the tongue and was able to line up four 12VDC batteries end to end... I did not have a height problem. I actually picked up four each of the plastic battery boxes from WALMART and mount ed them first then just set the batteries down inside the boxes. Then I added the snap in place lids...

This is photo of three batteries mounted end to end between my propane tanks and the trailer deck...

After adding the angle strips that extend out on both sides of the OEM mount I now have four 12VDC battery boxes mounted end to end..

Also TORKLIFT makes a battery hanger you use for one battery mounted under the trailer to the main frame under the trailer..

Another solution might be mounting one of these 48-inch SIDE-MOUNT TOOL boxes (PEPBOYS) and you can mount four each T105's end to end inside this box. This is better idea keeping the batteries more safe from being stolen when left unattended...

You can mount BLUE SEA HD Battery switches and battery vents on the inside of this box as well...

Roy Ken
TBammer
Explorer
Jan 24, 2016
RoyB wrote:
Some trailers have the pull out battery tray. If this is what you have perhaps you can remove the tray...

If it is going to be real close be sure to come up a way to make sure the batteries don't bounce up and short out the terminals on the top of the compartment...

Roy Ken

No, the tray is 2 pieces of angle iron welded to the A frame behind the hitch and propane tanks. No adjustment available without some real work. It is hard up against the trailer which angles up and toward the front. I would use hold down straps to keep them from bouncing. I think the twin group 24s is the answer.
Almot
Explorer III
Jan 24, 2016
TBammer wrote:
Anybody got any suggestions on alternatives, besides just getting a new 12V replacement

Get two 12V. I haven't heard anybody complaining on having too much usable energy. More AH -> shallower cycle -> longer battery life and longer stay before you need to recharge.
RoyB
Explorer II
Jan 24, 2016
Some trailers have the pull out battery tray. If this is what you have perhaps you can remove the tray...

If it is going to be real close be sure to come up a way to make sure the batteries don't bounce up and short out the terminals on the top of the compartment...

Roy Ken
RoyB
Explorer II
Jan 24, 2016
Trojan T105 spec sheet

Lookup TROJAN BATTERIES online for additional information...

Here is a better explanation for install height

TROJAN T105 Install Height

Roy Ken

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