6 volt or 12 volt batteries

[f150k]

Looking at an up grade to my 2 battery set-up in our new 5er. I can get a trojan t-105, 225 ah deep cycle 6v 67lbs. ( group GC24 ) for around $152. or $304. for 2. The trojan 225 SCS 130ah deep cycle 12v, 87lbs at around $199. or $400 for the pair. Am I thinking too much on this, looks like the 2, 6v at 450ah would be the best over the 2, 12v at 230ah for $400. 2 6v at 134lbs as to 2 12v at 174lbs. So with the furnace, LPG detector, and Refrig,( around 11amp draw ) I should be able to go several days between charging.

[Taylorgso]

Originally Posted by f150k

Looking at an up grade to my 2 battery set-up in our new 5er. I can get a trojan t-105, 225 ah deep cycle 6v 67lbs. ( group GC24 ) for around $152. or $304. for 2. The trojan 225 SCS 130ah deep cycle 12v, 87lbs at around $199. or $400 for the pair. Am I thinking too much on this, looks like the 2, 6v at 450ah would be the best over the 2, 12v at 230ah for $400. 2 6v at 134lbs as to 2 12v at 174lbs. So with the furnace, LPG detector, and Refrig,( around 11amp draw ) I should be able to go several days between charging.

6V batteries in series combine voltage (thus 2x6V=12V), but not amperage - you'd still have only 225ah. 12V batteries in parallel combine amperage (thus 2x130=260ah) but not voltage - you'd still have 12V. However, with the 6V in series, you'd have greater longevity than with the 12's. The ideal solution would be two banks of 6V batteries - each bank with two 6V in series, then the two banks connected in parallel. If you have room for them!

[Stank Bait]

I went through the same dilemma as you awhile back. Read all the posts 6V vs. 12V and decide for my needs that 12V was best. This is why. I have owned lots of trolling motor batteries that are connected in series. I have had one battery go out more than once. I figured if I had one 12V working on trailer I could still operate. If I dropped one 6V the other one would not power anything. Very little in discussions were mentioned about this. I figured that 1/2 of a 12V system was better for me that 1/2 a 2 x 6V system. Just something more to think about. I am sure I did not help.

[f150k]

Yes, you have a good point and also if I want to use trimetric ( Tm2025RV ) monitor they only work on 12volt.

[garbonz]

Originally Posted by f150k

Yes, you have a good point and also if I want to use trimetric ( Tm2025RV ) monitor they only work on 12volt.

The trimetric works on the combined 2 six volt as well as the 12 X 2, no difference. I am not sure what the point is, as you will have either set combined and they will fail together. If you separate the 2 12 volts with a switch then you will have reduced capacity due to peukert's law.

Bottom line is either will work fine if they are Trojans.. More important is get a good charger and monitor, keep the electrolyte topped up and use the ones that fit best and you can afford.

[RodeoGeorge]

Originally Posted by f150k

Yes, you have a good point and also if I want to use trimetric ( Tm2025RV ) monitor they only work on 12volt.

I am of the same thinking regarding using two 6V batteries. If you have only two batteries and loose one, you are dead in the water.

Using two banks of 6V batteries adds a lot of weight, and if you have a lite series RV you really eat into your CCC. In larger RVs this is not normally an issue.

Regarding the TM-2025RV, you would use it to monitor the combined series voltage of the two 6V batteries, so it can be used with the 6V setup.

RodeoGeorge

[TeJay]

Trojan does make a good heavy duty deep cycle B+. When our first B+ fails we'll go with 2-6-V's hooked in series. More capacity and good but not to expensive B+'s that will last 4-8 years or longer. The one's in our MH that we sold were 8 years old and still going strong. You'll find opinions both ways so research and do what you're comfortable with. If you are concerned with one B+ failing and you only having 1-6-V B+ left I wouldn't worry. If both B+'s are purchased at the same time and placed on the same converter/charger they will both be discharged/charged the same and will most likely last about the same length. If you do get a defective B+ you will most likely find it in a relatively short period of time. If that did happen I would ask to replace both because you are connecting them in series and you do want B+'s that are of the approximate same age.

JMTCW
TeJay

[garbonz]

Originally Posted by RodeoGeorge

I am of the same thinking regarding using two 6V batteries. If you have only two batteries and loose one, you are dead in the water.

Using two banks of 6V batteries adds a lot of weight, and if you have a lite series RV you really eat into your CCC. In larger RVs this is not normally an issue.

Regarding the TM-2025RV, you would use it to monitor the combined series voltage of the two 6V batteries, so it can be used with the 6V setup.

RodeoGeorge

Are we losing the batteries as in stolen , or them going bad? Never seen one 6 volt in a pair going bad by itself. Maybe that happens but I doubt it, at least with decent care. If it does then that would argue for the 12's.

I do wonder if the larger individual cells in the 6 volter's would be of some advantage. Maybe a call to Trojan would be an idea?

Using the 2 12's or the 2 6's are the same weight wise given the difference in amp-hours.

[flymhi]

You should be able to get better battery pricing than that. Try the golf cart dealers as the one I called yesterday in SC sold 105s for $99ea with exchange.