Quote:
quote:Originally posted by Dave e Victoria
The original question was "is 2 6-volts in series better than 0ne 12 volt?" The short answer is of course. But the long answer is different as it is unfair to compare 1 battery to two batteries.. The correct question is, "If I am willing to carry two batteries,, is it better to carry two tweves in parallel or two sixes in series?" I really doubt that it makes much difference as long as you compare like specs. And, there is the tricky part. (Like they say, the devilis in the details) [...]
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Correct. Given that the 2 12v in parallel and 2 sixes in series have the same total amp hours, it should be a wash. However,
the reason that I like the golf car batteries (2 sixes in series) is that the golf car battery is built as a deep cycle battery. "Marine" batteries are a compromise between a starting battery and deep cycle. An RV uses power slowly over a long period of time. A car or truck uses its battery in a very short high current burst.
If you had a motor home that was also using the starting battery to power the coach, then you might want to think about Marine. HOWEVER, for 5th wheel or TT use, there is NO starting requirement. Why compromise?
It would take physically more deep cycle batteries to provide the high current burst to start a truck, but they could do it.
The starting type battery
can power your RV,
but the life span of that type of battery is less than a real deep cycle.
The Marine battery will be somewhere in between.
If you look at the golf car battery, you will notice that they are taller than a starting battery. That is because they have more space under the plates to allow plate material to fall and pile up during normal use. Once that plate material reaches the bottom of the plates, the battery is done. So, given that the battery is kept charged to prevent sulfation (a coating on the plate that prevents the acid from making electricity), it will last longer. Also, the plate thickness of the deep cycle battery is WAY thicker than a starting battery. That allows plate material to fall off and still have a plate to work with.
Another advantage of the golf car battery, since it only has 3 cells there arn't as many internal walls so there is more room for more plate material. It is one of the reasons that two 6v batteries TYPICALLY have more amp hours of capacity than 2 12 volt batteries (
given similar size). Of course, more plate material means that the 6 volt batteries will TYPICALLY be heavier than a 12v of the same physical size.
Factoid from the electric vehicle crowd, it takes about 1000lbs of lead acid batteries to provide the engergy equivalent of 1 gallon of gasoline.
The amount of lead you have matters....
Also, if you price batteries per amp hour, I think you will find that golf car batteries are about the best bang-per-buck out there. I can get them at Sam's Club for about $45 a pop.
OTOH, if you never dry camp, then there really isn't any issue.
Eric