Forum Discussion
29 Replies
- BFL13Explorer IIThe "load" wires do not have to be the same length or the same R. It is the links between batteries that need to be even for R so the batteries share equally. The load wires do have to be "across" the whole bank for balance. No "downstream" batteries.
The load/charging wires are in a circuit so it is the total R of the Pos and Neg paths that counts. Pos and neg paths can be different such as when the Neg uses the Rv's frame and the Pos uses wires.
You can have a situation where the same wires do both jobs, so they should be even. An inverter with two pos and two neg wires on batts in parallel such as a pair of 12s, can have one of each wire to each side of the pair. That way you don't need any actual parallel links as well as the inverter's wires. Idea being each battery does half the work. In real life you can be close enough and swap batteries around every so often to even their lifespans.
Where you can't get proper balance you can do the same thing. Rotate the batteries in the bank over time to get even wear. - jrnymn7ExplorerUnder-wiring and cheapo terminals cause increased (unnecessary) voltage drop, decreased efficiency and excessive heat. Nothing to do with perfectionism... it has everything to do with professionalism.
- jrnymn7ExplorerSCVJeff,
Good catch, I missed that. Yes, the pos and neg leads should be to/from two opposite strings. - SCVJeffExplorerOP- Yes, your drawing is correct as far as not blowing things up. What everyone is trying to say with all the pictures is that they want you to wire as you have done, BUT move the main positive OR minus cable (not both) to the other battery. The point being is to have exactly the same length of cable to each battery.
Strange as it seems, even with giant wire, there are losses. AND all the perfectionist power geeks HATE that because it's such an easy fix. It actually can affect the life of the batteries both daily and full life. SO, take that positive lead on the drawing and move it to the lower battery. BAM ! - pianotunaNomad IIIHi Wolfe10,
Unfortunate odd numbers (3 12 volt) can only be balanced using a buss bar with leads to each set of batteries. This is wiring pattern #3 at the smartgauge site.
It is not in the least elegant but it is the only way to have balanced connections. - wolfe10ExplorerI really like smkettner's 4 6VDC battery layout.
Would like this same kind of simplistic yet elegant arrangement for 6 6VDC battery layout-- a common layout in newer coach/those with large inverters. - pianotunaNomad IIIHi Richard,
To reduce resistance from the connections.
It is one advantage of 12 volt jars. - RLS7201Explorer II
pianotuna wrote:
Keep the interconnect wires one size larger than the connections to the RV.
If each 12 volt group only carries ½ of the load, why make the interconnect wires one size larger then the main feed wires going to the coach/charger?
Thanks
Richard - NinerBikesExplorer
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