Looking for Combo Washer+Dryer for off grid RV use

zoneblue

Still curious to see how that bank is configured. 1500Ah doesnt divide evenly by any of the common LFP formats. 5P4S 300Ah maybe?

shaun

shaun

Picture shows position of previous AGMs, Lithium is 18.5KWH circa1,500amps, www. balqon.com, weight approx 300lbs,within weather proof box, sits nicely between main chassis rails

shaun

shaun

shaun

Pictures showing inverter to battery cable thickness, old battery compartment, allowing access to main lithium fuse and battery cables/connection/trip/reset

shaun

Hi Solar Expert, thanks and I have left them a request to contact me, 

shaun

shaun

shows Norris RV tech with the 9 solar panles

zoneblue

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.

Blackcherry04

A picture is worth a 1000 words, but it's hard to tell the scale. The cable from the battery bank to the buss posts doesn't look like 4/0, but may be. It is marked, so you'll be able to tell. With 12v your going to have some voltage sag, but LFP operating voltage range will help you on that.

For me, I would have never installed it like they did, but do to it's boxed prefabbed size maybe it was best.

Good luck with Inverter sales, you'll get to see a lot of Prevost Coaches and Country Music Stars coaches there for maintenance sometimes. It's a big operation.

zoneblue

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.

shaun

Hi All, PJ from Inverter Service Center has sent me this link in regards to the washer / dryer issue, this does not deter from the need for correct wiring

http://mvvikingstar.blogspot.com/2013/03/summery-and-conclusion-compatibility.html

Any comments

mike95490

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.

Dave Angelini

Definitely (as was stated)  more than one would want to know. And he also stated you probably will never stop learning on a boat like this. I can remember these same issues all over the world on my boat. I had a locker full of motor start capacitors and 100 watt light bulbs. Some things never change and this issue (different equipment) is at least 25 years now.

lampshade

This is a very old thread, which I ran across doing an internet search.  However, it doesn't have the correct answer, so I'm updating it.  There IS an incompatibility between Magnum inverters and Splendide machines.  I've experienced it myself, and I somehow figured out that if I plug a space heater into the inverter along with the Splendide, the Splendide will work.  Here's a more scientific exploration:

http://mvvikingstar.blogspot.com/2013/03/summery-and-conclusion-compatibility.html