B and C
Well-known member
doublegregg said:well, i'm looking at my current batteries (two, used gel, 51ah each) as a learner set... probably...
Yes, not much capacity and you have already discharged below the 12.2 threshold.
so i put one of them, which i charged fully, on my 50L fridge (on an inverter). i left it connected for 6 hours. the voltage gradually dropped to 11.61. i disconnected it. i'll see if the voltage rebounds... so, it works......... for awhile...........
You should have plugged it in as a 12V device because inverters are inefficient. They can waste 20%. Plug it into the house to get it to temperature before trying to run it on battery.
it seems like knowing the total amps going in and out, over time, would be good to know. do controllers keep track of that? i know a couple people here (hdr) mentioned a trimetric device, and then there are various cheaper devices, but don't no if those just give a reading of what is happening right then, rather than a log. soundslike the trimetric keeps a total. what is a shunt?
A shunt is a known value resistor that one side is connected to the battery negative and the other side is connected to ground. Two little wires attach to the shunt that goes to the meter. Maybe three little wires, it has been a few years. The trimetric does have a data logger that I have never looked at. The trimetric will show how much battery is remaining and how fast you are using electricity as well as how many amps in and out. Someone else may be able to help with the data logger. My solar charge controller is a midnite kid with the whiz bang jr. I don't use the trimetric charge controller.
and now i'm starting to think of what type of battery i'll eventually get. i'm thikning agm vs liion phosphate... but leaning to agm because of the cost of a 100ah liion, which is like $900. as i said, i'd be worried about them getting stolen, or me doing something to break it... windy nation 100ah agms are less than $200 ea. i'm thinking if my fridge needs approx 30ah a day, over 3 days that's 90ah, so i'm thinking of trying to get 200ah of battery.... i'm figuring agm will be half the price of liith ion? i'm leaning away from flooded lead acid cause of the spillage potential, and off gassing in my living compartment.......... i've read they can last longer if you take care of them.... i think i might not want that burden.
Two LA 6v LA golf cart batteries are probably the longest lasting battery in the LA chemistries. I have two 125Ah AGM batteries that weigh 100# each and another 100 Ah AGM battery that I added because it was lying around doing nothing. Not the best way to connect batteries. Ideally, they would all be the same age and size.
i do like the size of my current batteries. securing four of them, since i want 200ah, and wiring them, might be harder than two large 100ah batteries. but i'd prefer working with lighter batteries. i think they're 40#. 60#, for the 100ah agm's, is heavy.
Two 12V batteries
Four 12v batteries