2 12 volt batterys or 2 6 volt
what gives me the most bang for my money. every other rig that I have bought always had 6 volt battery's but the new one has 2 12 volt. not sure what works better.
Forum Discussion
SoundGuy wrote:
......snip........ as this to me is a clear indication that Trojan believes their SCS series is the most suitable, designed specifically for recreational vehicle use by engineers who understand far better than any of us the many considerations in battery design. Yes, the popular T-105 is also considered suitable but it's also listed in the Golf and Utility Vehicle brochure along with the T-1275, making these universal use deep cycle batteries which are NOT offered with recreational vehicle specific DWNT terminals. My point - who are we to argue with Trojan? :h If it weren't for the fact I can get a deal on a pair of RV Care branded Deka 12 volt Group 31s for half the cost I'd have no hesitation in accepting Trojan's recommendation that a pair of Trojan SCS225s would be an excellent choice for my intended use with my own travel trailer. :D
Don't go quoting facts and manufacturer's information to us. We know what we know and have known it for a long long time.brulaz wrote:
According to Trojan, their T-1275 is a "12V Deep-Cycle Battery", and the SCS225 is a "12V Marine/RV Deep-Cycle Battery".
While all this forum theorizing makes for interesting reading it seems to me that if the goal is a battery designed for recreational vehicle application one would logically turn to a manufacturer that designs and builds these products for the most appropriate recommendation. Go to the Trojan Marine / RV Webpage, scroll down to the bottom, download the Marine / RV Brochure, and one doesn't even find the T-1275 listed as an appropriate solution. Indeed, if one ignores the many variations of any given battery that is listed as appropriate for RV use there really aren't that many different choices ... but interestingly, of ALL of those choices recommended by Trojan only one - the 12 volt SCS series - is offered with the terminal that makes the most sense for recreational vehicle use - the DWNT (double wing nut terminal) which allows easy connection of many cables to the batteries. Coincidence? ... hardly, as this to me is a clear indication that Trojan believes their SCS series is the most suitable, designed specifically for recreational vehicle use by engineers who understand far better than any of us the many considerations in battery design. Yes, the popular T-105 is also considered suitable but it's also listed in the Golf and Utility Vehicle brochure along with the T-1275, making these universal use deep cycle batteries which are NOT offered with recreational vehicle specific DWNT terminals. My point - who are we to argue with Trojan? :h If it weren't for the fact I can get a deal on a pair of RV Care branded Deka 12 volt Group 31s for half the cost I'd have no hesitation in accepting Trojan's recommendation that a pair of Trojan SCS225s would be an excellent choice for my intended use with my own travel trailer. :Dpnichols wrote:
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Probably total internal intrinsic resistance of the battery bank has a lot to do with the amount of voltage sag under heavy current loads.
Too bad that value is not readily available for batteries. Maybe lifetime # cycles to 50% might be as close a correlate as we can get from the spec sheets. But even there, I don't see it often reported for the "marine/rv" types, just the C.A. and C.C.A.
I wonder what setup has the lower total internal resistance ... two GC 6 volters in series or two deep cycle 12 volters in parallel? (Apples-to-Apples assuming that all batteries are flooded or all batteries are AGM.)
You are thinking that in the parallel configuration the resistance is halved, while it is doubled in the series config, like ordinary resistive components? No idea whether that holds true with batteries but it would nice if it did.
I do find the "12V deep cycle" language confusing.
According to Trojan, their T-1275 is a "12V Deep-Cycle Battery", and the SCS225 is a "12V Marine/RV Deep-Cycle Battery". I guess you are referring to the formerbrulaz wrote:
Can C.A. or C.C.A. be used as measure for V sag?
Probably total internal intrinsic resistance of the battery bank has a lot to do with the amount of voltage sag under heavy current loads.
I wonder what setup has the lower total internal resistance ... two GC 6 volters in series or two deep cycle 12 volters in parallel? (Apples-to-Apples assuming that all batteries are flooded or all batteries are AGM.)landyacht318 wrote:
Trojan's own group31 is rated at only half the cycles as the T-1275. 600 vs 1200 cycles to 50%
If powering an large inverter near its maximum is not a concern, the T-1275 is the clear winner.
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And T-105 6V GC2s are even better, around 1700 cycles to 50%.
Guess that's the compromise between a true deep cycle battery and a "Marine/RV" 12V battery: # cycles to 50% versus V sag under heavy load. Like Mex says ...
Maybe the T-1275 12V deep cycle is somewhere in between two T-105 GC2s and Trojan's SCS225 "Marine" 12V.
Can C.A. or C.C.A. be used as measure for V sag? Prolly doesn't matter as Trojan (and others) don't even list a C.A. or C.C.A unless they consider the battery a "Marine/RV" battery.
I hate compromise. Maybe I'll just wait for LiFePO4 batts to fall in price.:(- dupe
Mex wrote:
"Gentlemen, select your compromise. Choose wisely."
Mex .... you need to get out on the NET more.
Haven't you kept up on how money can eliminate compromise? Trade money for lithium and there is no more compromise possible or needed.- MORE...
PANELS!
C'mon! Having the acceleration of a Bugatti, the economy of a VW turbo diesel and the carrying capacity of an F-450 ain't gonna happen except in your dreams. Dense plates make for CCA ratings in the cellar.
"Gentlemen, select your compromise. Choose wisely." pnichols wrote:
Of course with a deep cycle 12V AGM battery you can get the best of both battery worlds:
- Power for small loads over a a long time-period into lower states of charge without damage to the battery, and
- power for short term large loads without much voltage sag due to the low internal resistance of AGM batteries.
Nirvana ... at a price.
Agree, but our batteries remain partially charged for days as we only have solar. Really need to equalize them afterwards. Don't think AGMs would like that.- Trojan's own group31 is rated at only half the cycles as the T-1275. 600 vs 1200 cycles to 50%
If powering an large inverter near its maximum is not a concern, the T-1275 is the clear winner.
In my area the SCS 225(group31) and the T-1275 are the same price,~180$ before tax and core charge.
I was making modifications to shoehorn a T-1275 where a group31 just barely fit, but I found a single group27 AGM meets my needs for both engine starting and house duty, since I can currently also plug in whenever I want, and have a 40 amp adjustable voltage charging source which makes my Northstar AGM battery dance for joy when I do hammer it with 50% discharges night after night.
