That 29HM 12V battery only weighs 61 lbs I think I read somewhere...
The Trojan GP27 12VDC Battery weighs around the same weight so I suspect you would get around the same performance level. When loading down @25 AMPS the capacity will be around 200 minutes (3.3Hours to zero charge state)
Using two of the Trojan GC2 6V batteries in series will weight in around 124 lbs of batteries when you add two together to get 12VDC. You will get alot more capacity @25 AMPs draw down with the GC2 batteries. This will be around 447 minutes (7.45 Hours to zero charge state)...
Of course you would never want to run them down that far and keep them always above the 50% charge state...
When i am charging my GP24 12VDC batteries with my PD9260C converter/charger I immediately see around 52-53AMPS DC Current going into my three GP24 batteries when I hit them with 14.4VDC. SOme have told me my PD9260C may be doing some current limiting at this point but that is what I read on Battery monitor panel I made up. In about 15-20 minutes I see the DC Current start tapering back and in one hour my PD9260C will then switch to 13.6VDC mode. My total DC current is them reading with the three GP24 batteries connected around 8 AMPs or so. If this continues on for a couple more hours at 13.6VDC then I see the DC current for the three GP24 batteries showing around 2-3AMPS DC current. This is what I call the 90% state of charge. I get almost full performance out of my GP24 batteries doing this... i.e. My normal parasitic drain is around 1AMP or so and usually between between 6PM and 11PM I will see up to 22-24AMPS DC current being drawn from all of the the things we are running off the batteries. After we go to bed around 11PM I make it just fine to 8Am the next morning with my DC VOLTMETERS reading around 12.0VDC. This is what I call the 50% charge state. Now I can my my 2KW generator with the shore power cable connected to it and this will bring my three GP24 batteries back up to around 12.6-7VDC in three hours generator run time. This is powering up my PD9260C converter/charger to charge my batteries.
This is what I have been doing since around 2009 camping off-grid in my OFF-ROAD POPUP camper. Just last season my three GP 24 batteries start taking longer and longer to charge up and of course running down to the 12.0VDC level much quicker than before. It is game over for me now with these batteries. Working on a new battery setup for this coming season using two groups of GC2 6V batteries in series to get me in the 450AHs capacity as compared to the 255AH capacity I was getting from the three GP24 12V batteries in parallel.
This is what has been working for me
Roy Ken
