12 V Batteries-Planning for Full-time

Remember, there is no 12,volt deep cycle batteries made.

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That is simply untrue.  I'll grant you won't find them at Walmart, nor even at many RV stores, but they are available from battery specialty shops.  Trojan makes them in several sizes and in flooded cell, AGM and Gel types. Concord/Lifeline makes them in the AGM type, as does Optima and Rolls-Surette. And US Battery makes a 12v equivalent of their well-known GC2 6v deep cycle.

I completely agree with Gary RV Roamer on this:

12 volt true deep cycles are available and are not hard to find. I use them and I'm a fulltime boondocker.
The Trojan J150 is the 12 volt equavilant of the T105's 6 volt only in a 12 volt package. In terms of amps hrs and amp hour per price and weight per amp hour the J150 is = the exact damn same as the T 105's.

difference is its in a 12 volt package vs a 6 volt package. which means you have same voltage, same weight per amp hr  and same price per amp hr as the t 105's.

so if you would like 450 amp hrs, 3 j150's give you that as does 4 t 105's. Would you like 3 12 volt batteries that you can use independently cause all three batteries are 12 volt or would you like 4 6 volts t 105's that you can't use independently??? cost & weight per amp hr is identical.

Price, weight amp hrs is identical but each of the 3 12 volt j150' can be used inependently so YYYY!!!! would you want 4 - 6 volt batteries????? that can't be used independently?????

US Battery also makes a J150 equivalent which is the US12VXC at a US Battery Co. rated 155 amp hrs.

Thanx........INTjohn

I have installed an scs225 Trojan 12 volt deep cycle agm battery to my bank of two 6 volt flooded cell batteries. Agm because it is under my unit behind the axle - not going to check the levels very often... And it has very nearly the same charging parameters as the 6 volt set up. Now I can handle 3 cloudy days in a row. If it's cloudy longer than that I will want to move anyway.

INTJohn said:

The Trojan J150 is the 12 volt equavilant of the T105's 6 volt only in a 12 volt package. In terms of amps hrs and amp hour per price and weight per amp hour the J150 is = the exact damn same as the T 105's.

difference is its in a 12 volt package vs a 6 volt package. which means you have same voltage, same weight per amp hr  and same price per amp hr as the t 105's.

so if you would like 450 amp hrs, 3 j150's give you that as does 4 t 105's. Would you like 3 12 volt batteries that you can use independently cause all three batteries are 12 volt or would you like 4 6 volts t 105's that you can't use independently??? cost & weight per amp hr is identical.

Price, weight amp hrs is identical but each of the 3 12 volt j150' can be used inependently so YYYY!!!! would you want 4 - 6 volt batteries????? that can't be used independently?????

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I found this to be VERY interesting information so had to do some research.

I found (on Trojan's site - http://www.trojanbattery.com/pdf/datasheets/J150_Trojan_Data_Sheets.pdf) that the J150 has a capacity of 150 Ah (at the standard 20 hour rate), weighs 84 lbs and measures 13.7" long x 7.13" wide x 11.13" tall.  Four of them (for comparison sake) would yield 600 Ah (at 20 hour rate), weigh 336 lbs, and cost about $200 each (that was the cheapest price I found online).

My four 6 volt golf cart batteries from Batteries Plus (SLIGC115) are 230 Ah (at 20 hour rate), weigh 64 lbs, and measure 10.25" long x 7.125" wide x 10.875" tall and cost $100 each (using the current 10% off pricing deal).

So, for comparison, the cost per Ah is about $1.33 for the J150 versus $0.87 for the golf cart. The length of the J150 is such that I could not fit four of them in my existing battery tray and that would cause MAJOR issues or limit me to only two or three of them.  The weight of four J150's is 336 lbs vs. 256 lbs. Clearly, having 300 Ah of usable power over 230 Ah would be really nice!

So, to answer your question. I chose the 6 volt batteries because they fit in my existing battery tray without modification.  The weight savings is nice but not significant when talking about a 35,000 lb coach, the cost savings is nice ($400 vs $800) but not super significant.  I would like to have the extra 70 Ah though.  The concept of "independent" use means little to nothing to me. If one of my four die, I will remove two of them until I purchase replacements.  I've never had just one completely die when being properly cared for so perhaps I am seeing thru rose colored glasses.

JFNM - you're research is somewhat shoddy.

T 105's wiegh about 60 ish pounds and produce 225 amp hrs ; 4 of them wired for 12 volt usage yeilds 450 amp hrs at about 240 pounds........

Cost $100ish bux a piece x 4 = 400ish $.

The J 150's are about 80ish pounds and produce 150 amp hours; 3 of them wired for 12 volt usage yields 450 amp hours - identical to the 4 105's.

Weight too is basically identical as the 3 J150s weigh TAH DAH!!!! about 240 pounds - same as the four 105's at about 240 pounds!
Price of my J 150s - 3 at 135ish$ = 400ish $.

NO DIFFERENCE! Volume footprint is pretty much identical as well. do the math.
.......and again if you would like the option to use them idependently as I do then YYY!!!??? would you opt for 4 6volts or even 2 6 volts vs 3 12 volts or 2 12 volt J 150's???
The Trojan J 185's are another excellent 12 volt deep cycle batterry...........

Thanx............INTJohn

Yep, you are absolutely right - I really blew it on the price.  Terribly sorry about that.

How many times in the last two years have you used these batteries independently?  I wonder if perhaps they are very failure prone and that is necessitating the need to do this??

An issue that is very specific to some installations (mine) is the height available in the battery compartment.  My existing 10.8" tall batteries are a VERY tight fit (and I mean scraping the top tight).  I suspect 11.1 might be too tall for me but I've not tried it so can't say for certain.

my itasca had a worn out car battery for  the Coach.  was so bad seller had to boost it to start the power plant. i thought the powerplant would start off the main 2 chassis batterys?  anyway, i put in 2 1200 amp RV batterys. and have a 100 watt solar panel to install somewhere on it too.

  After cruising through all 26 responses, I am under the impression that you need to understand that you are not going to "get all the amps you can get"  A battery ,or bank as we refer it, is only that, a "bank", its empty until you put something into it, its only a "saving device" you only get out what you can put in, and only about 50% of that at any one time!!.>>>Dan

Great analogy Dan!

Gary, the link to the article on Batteries on the RV forum you provided was excellent.  THANKS!  Very informative and found out batteries and options are not simple but the article was very informative and helpful.  From your other comments on this post it is apparent you know your stuff about batteries  Very much appreciated. Ken

Glad you found it helpful, Ken.