Looking for Combo Washer+Dryer for off grid RV use

Thanks for those pics. Im guessing the guys that did the LFP conversion reused the old wiring from the previous smaller lead bank... Oops.

The battery is a preconfigured module pack: http://www.balqon.com/store-2/#!/12Volt-18-kWhr/p/47184751/category=12286436 . 4P4S 375Ah, i guess. They rate them for 350A continuous. They are probably quite appealing for larger RVs as they just drop in.

However, from a technical point of view, such an upgrade would benefit greatly from a reconfiguration to 24V. Half the amp hours, half the amps, one quarter the cable for the same cable power loss. And it decreases your charge and discharge rates, and lots of other nice stuff.

However, not much you can do about that now (its still very much a 12V culture in the RV world) . And with lithium, they are just so flexible in terms their charge requirements. You just need to be aware of the amps in the complete chain from the inverter through to the disconnect and onto the battery. As a guide my 24V, 10kWh battery,1/0, 3kW inverter has around 0.3% voltage drop in that whole cable train. Even with 4/0 yours will be 4 times that.

The reason we want really tight voltage drop in that cable (not only to prevent waste) is that the charging system for lithium is critically dependent on accurate terminal voltage.

Yes insulation thickness varys a lot and makes size difficult to determine from a visual inspection.  Its not that common but you can buy flexible LV cable all the way up to 600mm2. eg: http://www.generalcable.co.nz/Home/Products/Power/Low-Voltage/LV-Distribution.aspx

The nice thing about metric units is that you can do the math easier. In my ideal world, that cable would be:

a= 2 * d * p * 1000^2 / R  , where R= 0.3% * V / I
where:
a is cable cross sectional area in mm2.
d is the one way cable length
p is resistivity of copper at 20*C
R is the resistance of the round trip cable
V is the system voltage
I is the inverter current at the rated capacity
0.3% is the target voltage drop

Thus:

a= 2 * 1.3m * 0.000000017 ohm.m * 1000 * 1000  /  (0.003 * 12V/ 300A) = 368mm2

By comparison 4/0 is only 107mm2.

As for the Magnum and the washer / waveform problem, i recall a ways back halfcrazy saying something about magnum's regulation. Maybe thats related.

it would be fun to put that gear on a Power Factor meter and see how bad it is.  I have a 40A 12VDC switching battery charger that is .55PF  really bad, but my genset powers it OK
A 50uF Run Cap seems really large, bu maybe the interaction is so bad, that it's needed.  For a small motor, I'd have thunk that 20 or 30 uF  would have been the ticket.