there are more opinions about 6 Volt vs 12 Volt house batteries, than peas in a pod. I have my own thought too and it is that 6 VDC are the only real deep cycle battery. I had all kinds of "marine deep cycle" on my boats and none of them were true deep cycle. They all were used for starting 454 engines and keeping lights on at night while at anchor. They did what we needed but none lasted more than three years.
Once I went to a true deep cycle battery system I was able to run my residential refrigerator, stand alone ice maker and watch tv or run the stereo. I tried going with 12 VDC for house batteries and they crapped out in no time like two years. I went back to 6 V DC batteries and they are just great.
I still prefer the flooded batteries = 6 volt for house battery. See Picture below - notice there are no extra patch cables. I made buss bars out of aluminum stock and wrapped with tape to insulate in the event of a dropped tool etc. at less than $100 each they offer the best balance of bucks for battery or dollars for amp hours.
There is more to the design than just more lead. The composition of the Grid is also of improved material allowing for expansion during discharge, as well as the density of the surface material for a different rate of discharge which really makes it a deep cycle battery. So thicker and better relate to longer life. The space below the grid is greater which allows for more space below the grid, for material that will slough off the plates, to accumulate harmlessly before shorting out the plates and ending the life of the battery.
Most (90%) of 12 v so called marine deep cycle are designed to be able to support the high rush current required for starting large long cranking engines like the 454 cu in commonly found on boats and RV's. These batteries are a compromise of engineering to TRY and meeting the needs of both worlds. High Current and Slow discharge. Since they try to pack this into the group 31 or 27 you will find the physics and science just will never equal that of other types of batteries. This is why they generally do not deliver the expected result over the course of time.
I prefer dedicated batteries for specific usages.
Once I went to a true deep cycle battery system I was able to run my residential refrigerator, stand alone ice maker and watch tv or run the stereo. I tried going with 12 VDC for house batteries and they crapped out in no time like two years. I went back to 6 V DC batteries and they are just great.
I still prefer the flooded batteries = 6 volt for house battery. See Picture below - notice there are no extra patch cables. I made buss bars out of aluminum stock and wrapped with tape to insulate in the event of a dropped tool etc. at less than $100 each they offer the best balance of bucks for battery or dollars for amp hours.
There is more to the design than just more lead. The composition of the Grid is also of improved material allowing for expansion during discharge, as well as the density of the surface material for a different rate of discharge which really makes it a deep cycle battery. So thicker and better relate to longer life. The space below the grid is greater which allows for more space below the grid, for material that will slough off the plates, to accumulate harmlessly before shorting out the plates and ending the life of the battery.
Most (90%) of 12 v so called marine deep cycle are designed to be able to support the high rush current required for starting large long cranking engines like the 454 cu in commonly found on boats and RV's. These batteries are a compromise of engineering to TRY and meeting the needs of both worlds. High Current and Slow discharge. Since they try to pack this into the group 31 or 27 you will find the physics and science just will never equal that of other types of batteries. This is why they generally do not deliver the expected result over the course of time.
I prefer dedicated batteries for specific usages.