12V or 6 Volt Batteries

[mobilcastle]

What is the advantage of having (2) 6V or (2) 12V batteries? Many have (2) 6 volt? What are good brands of deep cycle batteries and aprox cost? My 12volt is about 4 years old and I am thinking about replacing with (2) batteries although it seems to be working fine right now.
Thanks for the education.
Steve

 

[lwmcguir]

Re: 12V or 6Volt Batteries

You will hear from most folks to go with 2 6 volts, however in our experience in Campers, Trucks, Tractors, GEM car, and so on, 12 volt's are much better and you can still get decent performance with a weaker battery in use for two battery installations. Go with sealed batteries or even Gel, that is what we do for the Coach.

 

[brianharrison]

Re: 12V or 6Volt Batteries

12V vs 2-6V --> lots of reasons here is a link to one internet site.

Basically, 6V are made as heavy duty deep cycle with more lead/materials on plates/innards to create greater capacity (Ah storage and quality of construction). Usually the heavier the battery (due to plates/lead) the better capacity and performance).

That being said, there are some good 12V deep cycle. Trogan T105's (2 in series) are a great battery of choice to replace a single 12V. About 90 to 125 bucks each, retail if you shop around.

Brian

 

[Jimsryker]

I am currently undergoing this decision process, and one opinion from a co worker who also tows an RV, was to stick with 12 volt batteries. He had an experience where one of his 6 volt batteries failed (rare I know) but it left him and his family high and dry. He spent the day driving to effect repairs with two 12 volt batt. after that. Moral is, "if one dies, you can limp along until you can replace". 6 volts don't allow that.

 

[Invizatu]

Another thing to consider is... 2 six volts / wired in series = double the volts (12 volts) Same Amps as single battery maybe 310ah
2 12 volts / wired in parallel = 12 volts / Double Amps of single 180 X 2 = 360 ah
You end up with a few more amp hours with the 2 /12 volts (same price range batteries) and if you ever get stuck needing a battery for your truck, you can borrow one of your trailer batteries to get you by.

 

[scottyb]

Another thing to consider is... 2 six volts / wired in series = double the volts (12 volts) Same Amps as single battery maybe 310ah
2 12 volts / wired in parallel = 12 volts / Double Amps of single 180 X 2 = 360 ah
You end up with a few more amp hours with the 2 /12 volts (same price range batteries) and if you ever get stuck needing a battery for your truck, you can borrow one of your trailer batteries to get you by.

You have to go to a 4D or larger 12v battery to get 180 Ah @ $160 -$300 and 130 Lbs. each. 2 GC-2's give you 225 Ah for around $160 for the pair.

 

[pegmikef]

I wanted to put 2 Trojan T105s in my BH because I had very good luck with them with my TT boondocking, but alas, the battery boxes would not accommodate them, but would accommodate group 27 12 volt, so I ended up with a matched pair of them. I was willing to pay the extra money for the Trojans, but not the extra fifty bucks or so for new vented battery boxes, since the installed ones are brand new.

 

[Invizatu]

Scotty... Not sure what a 4D is, but I purchased (2) Energizer E27DC batteries from Sams Club for $84 each and it says they each have 180 reserve capacity amp hours. They are Deep Cycle Marine. They had the Energizer in six volt GC2 @208 amps (also $84 each). Two of the GC2 will give you 12 volt but only 208 amps vs the 27dc giving you 12 volt and 360 amp hours. What am I missing here?

You have to go to a 4D or larger 12v battery to get 180 Ah @ $160 -$300 and 130 Lbs. each. 2 GC-2's give you 225 Ah for around $160 for the pair.

 

[scottyb]

4D's are industrial batteries used for larger diesel engines. 8D's are the really large batteries used for really large diesel engines.

[h=3]Some common battery size codes used are: (ratings are approximate)[/h]

U1	34 to 40 Amp hours	12 volts
Group 24	70-85 Amp hours	12 volts
Group 27	85-105 Amp hours	12 volts
Group 31	95-125 Amp hours	12 volts
4-D	180-215 Amp hours	12 volts
8-D	225-255 Amp hours	12 volts
Golf Cart & T-105	180 to 225 Amp hours	6 volts
L-16, L16HC etc.	340 to 415 Amp hours	6 volts

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[Invizatu]

Scotty... So I guess I am still wondering why the group 27 that I bought is rated at 180 amp hours and your chart shows a group 27 at 85 to 105. Is it the marine deep cycle thing that gives it the higher rating to 180 ah?

 

[scottyb]

180 is the reserve capacity not 180 Ah. It is the number of minutes a battery can maintain a usable voltage under a 25A load.