Exide / GNB Marathons are AGM batteries. What size interconnects

Re: Exide / GNB Marathons are AGM batteries. What size interconnects

minimumly it should not be smaller than the biggest wire in the entire system. usually this would be wire going to an inverter, but is not limited to such. if such a system exists that need not have large wires it is still good to go as large as you can to keep interbattery connections low on resistance that increases imbalances and thus the need for eq charging more often. you want the battery bank to look as much like 1 battery rather than a group of interconnected batteries as is possible. though the wire resistances are small you must remember that the internal resistances of batteries are also small and the wire resistance can be large in comparison to the internal battery resistance. this could bring down the effective ah capacity of a battery bank as well.
i would say that there isn't any hard and fast rule to it at this point because of the many differing circumstances that may arrise, but a good guess might be to double the size of the wire over the largest being used as it has to handle currents going into as well as going out of the battery bank. if that turns out to be a small wire because the the currents into and out of the battery bank are small then go larger anyway. it is also common for copper buss bars to be used instead of or in conjunction with large copper wire.

Re: Exide / GNB Marathons are AGM batteries. What size interconnects

straight, hard bolted connects make me nervous. I wonder what the summer/winter heat cold charging cycles do. Will the plastic cases flex and leak ?
What about an upside down U shape, maybe made from 1/4" or 3/8" copper tubeing,
with S.G.'s terminals soldered on ? The curve in the metal will take up any mech stress, you have lots of copper to carry the current, and you can always slip some heat shrink sleeve over it, after 1 trerminal is on, the heat from soldering the 2nd terminal will shrink the sleeve.

Steel gets rust and corrosion easily, and with the humidity from the batteries and acid, it may not last long. Also, at high currents, you will see loss, you are not looking at 2", but 12 of them, and now you have 24" of the steel conductor.

Re: Exide / GNB Marathons are AGM batteries. What size interconnects

interesting arrangement and maybe if you have bolts of the right size you could double up on the bussbars too. no matter what you go with some reaction may occur on the metal so maybe some way of coating the bars to protect them could be in order just like that done on battery posts.

Re: Exide / GNB Marathons are AGM batteries. What size interconnects

those are some good points bill.

Re: Exide / GNB Marathons are AGM batteries. What size interconnects

mike90045 wrote: »

The crimps you speak of, are not hand crimps, they are machine made crimps, as you can't get the required pressure by hand. (pardon me sir, if you can crimp them by hand!)

There are hand crimpers for almost any size lug. Some are hydraulic, some are long handled (up to 4 feet) leveraged. They are not cheap though, costing up to $500 or more for the larger sizes.

Re: Exide / GNB Marathons are AGM batteries. What size interconnects

nigtomdaw wrote: »

...I can see the paralleled conductors having to supply safely 100amps but wouldnt the interconnects on the series side only have to safely supply 25 amps each !
...Still like comments on my series versus parralell current draw ?

A battery string with the least internal resistance would supply more current in a parallel configuration. So, the current is not always devided equally among the strings. I would suggest to put a fuse in each string. This is to protect the wire and a string that goes bad. If one string has a short cell for example, the remain strings would try to "charge" this string and there is nothing to limit the current.
GP