Why have 2 6v house batteries and not 1 12v? In fact, why not 2 12v or 4 6v?
Why have 2 6v house batteries and not 1 12v? In fact, why not 2 12v or 4 6v?
Because 6-volt deep-cycle batteries are a common battery size in wide spread usage in commercial and industrial applications .
They are found in many golf carts and other small electric vehicles.
No reason why a 12-volt or three 4-volt batteries, wired in series, wouldn't work, as long as they have the proper amperage rating..
Many have replaced their 6-volt batteries with 12-volt batteries, when upgrading to larger battery packs.
Larry
Two 6 volt batteries wired series for 12 volts is more reliable and longer lived than two 12 volt batteries wired in Parallel.
The reason, when one cell in one battery gets weak the other battery tries to charge it creating an internal discharge in the battery bank. In my light diesel truck it occured every 2 years, and separately the bateries would test good, but fail to start after a few days rest period. A solution is to isolate the two 12 volt coach batteries, and use them separately, i.e. a boondocking reserve. Or Reguarly Equalize the batteries. How it is done depends on the battery types.
Note that TOB (Those Other Brands) are currently having significant reliability issues with their controllers and inverter/converters using parallel battery systems.
I suspect most manufacturers use 12-volt batteries nowadays but it seems Lazy Daze has always used the two, 6-volt configuration, even now. Maybe they know something we don't?
They have upgraded to AGM though. From their website:
Top of the line LIFELINE brand maintenance free advanced AGM house batteries. Two heavy duty 6 volt batteries wired in series to produce 12 volts and yield 220 ampere hours.
Well,here i go again.
Does my 1995, 26.5 MB have the 2-6v configuration? I really haven't checked. My battery bousing is in front of the Genset. I have 2 new 6v golfcart batteries that i took out of my Cabin Cruiser when we sold it.
Thanks in advance AGAIN
Yes yours will have two six volt batteries unless the previous owners change it.
Thanks to all.
Two 6 volt batteries wired series for 12 volts is more reliable and longer lived than two 12 volt batteries wired in Parallel.
The reason, when one cell in one battery gets weak the other battery tries to charge it creating an internal discharge in the battery bank.
By the time one cell dies, the whole battery pack needs replacement since you should always replace batteries in sets, so they are the same age.
You shouldn't mix old and new batteries.
Individual cells die at the same rate in 6 and 12-volt batteries.
Feel free to configure you batteries anyway want as long as you have 12-volts and every battery has the same amp/hour rating.
LD probably originally went with the 6-volt, Trojan T-105 because they were the most dependable and widely available deep cycle battery available. T-105s are used by the millions in golf carts and small electric vehicles.
Larry
Why have 2 6v house batteries and not 1 12v? In fact, why not 2 12v or 4 6v?
True deep cycle batteries have thick lead plates. Those thick plates are why they can withstand so many deep discharge cycles. It also makes them heavy. I don't know how much the AGM's that LD uses weigh, but the 6V batteries typically used in golf carts ( Trojan T-105s ) weigh 62 lbs each. A 12V battery with the same cells would weigh almost 125 lbs. Difficult to handle.
Why not 4 6v? Great question! Is there room for 4 x 6V golf cart batteries in the battery compartment, and will that compartment support 250 lbs of weight ? ( I dunno, I'm just an LD maybe wannabe )
Lithium chemistry batteries generally have better energy density and much better energy to weight ratios, but are relatively expensive ( though prices are still falling ) and have a more complex re-charge cycle ( lest they burst into flame ).
True deep cycle batteries have thick lead plates. Those thick plates are why they can withstand so many deep discharge cycles. It also makes them heavy. I don't know how much the AGM's that LD uses weigh, but the 6V batteries typically used in golf carts ( Trojan T-105s ) weigh 62 lbs each. A 12V battery with the same cells would weigh almost 125 lbs. Difficult to handle.
Why not 4 6v? Great question! Is there room for 4 x 6V golf cart batteries in the battery compartment, and will that compartment support 250 lbs of weight ? ( I dunno, I'm just an LD maybe wannabe )
Lithium chemistry batteries generally have better energy density and much better energy to weight ratios, but are relatively expensive ( though prices are still falling ) and have a more complex re-charge cycle ( lest they burst into flame ).
I guess some people do use four batteries but to me the added weight would not be worth the added amp hours unless you decide to ditch the generator and it's weight in favor of full on solar with four batteries.
Two 6 volt batteries wired series for 12 volts is more reliable and longer lived than two 12 volt batteries wired in Parallel.
The reason, when one cell in one battery gets weak the other battery tries to charge it creating an internal discharge in the battery bank. In my light diesel truck it occured every 2 years, and separately the bateries would test good, but fail to start after a few days rest period. A solution is to isolate the two 12 volt coach batteries, and use them separately, i.e. a boondocking reserve.
This is true. Our '83 had a pair of 12V batteries, one stock, one I added. I was always fighting the issue Rodney mentions. A five year old battery would fail, and by the time I realized it, it would have trashed the two-year old one. Mine were mounted in different 'climate zones' on the rig, but even together, it is an issue. Also When wiring parallel batteries, it is vital to keep wiring balanced (equal lengths) to avoid current differentials affecting charging. This is true with a pair of 12V batteries or any series-parallel configuration; not an issue with a pair of 6V ones.
Steve
"A five year old battery would fail, and by the time I realized it, it would have trashed the two-year old one."
That isn't an argument against parallel battery hookups. As Larry pointed out, you shouldn't mix old and new batteries. Similar problems would have occurred in a series setup with two-year-old and five-year-old batteries. Neither arrangement is inherently superior.
"When wiring parallel batteries, it is vital to keep wiring balanced (equal lengths) to avoid current differentials affecting charging."
That's true. In my Lazy Daze, I had four 12 V batteries in parallel, daisy-chained together (taking + and - feeds from opposite ends of the chain). It worked fine as far as I could tell, but from a theoretical standpoint it wasn't ideal. In my Airstream I have two 12 V batteries in parallel, but rather than daisy-chaining them, I ran separate wires of exactly equal length from each battery to the positive and negative buses. If feasible, that's the best way to do a parallel hookup.