Lithium Ion Batteries for RV Solar???

Thanks. Yeah, I guess it is.

1.2v spread

Assuming your battery has a 13 series by xx parallel internally
That's v less than 0.1v per cell
Your Cell voltage ranges from 3.96 to 4.05v under load
That is very good, not any problem at all

Nominal voltage for Li cells is 3.7v
Fill discharge approx 3.0v fill charge 4.2v

Any thing below 2.8-3v can damage the cell

I'm no expert, this is just what I've learned from study on the web

Doing some more "back of the envelope" calculations 3780 watt-hours/ 48 volts =~ 78.75 amp-hours. Or about 316 amp-hours @ 12 volts. That is about what Mr Wizard has usable from his 5 telecom jars.

Load per cell for MrW is ~ 10 amps.

MrWizard wrote:
Li is know for holding voltage until almost discharged at nominal discharge rates

Yes. I didn't watch it drop so I don't know how steep the drop was. I was surprised to see it vary between 51.5 and 52.7 during certain loads. I wasn't expecting that much variation.

100*48
200*24
400*12
all come out to the same Kwhrs capacity

(4) GC jars are a common recommendation on these forums, and a similar capacity, but cannot be used repeatedly to the same depth of discharge

voltage drop at 0.9 of capacity

try drawing 0.9c from FLA, and get MORE voltage drop

Li is know for holding voltage until almost discharged at nominal discharge rates

i don't remember any 'text' claiming you can draw super high draw rate have NO voltage drop

100 x .9 x 42 = 3780 watts

Interesting that there *is* voltage drop on the LI if you push them hard enough.

I guess we now know that a 30 amp RV needs a 100 amp-hour LI pack at 48 volts.

pianotuna wrote:
I suspect that 2oldman can safely draw 1c or 5200 watts on his (magnificent) battery bank..

Thanks Don. At .9c there's a low-voltage shutdown at 42 volts. I didn't mean to do that!!

I went to exercise my generator and forgot that I had left a 1500 watt heater turned on. In the south I use my roof air for loading the genny.

I did find out that even with load support from the Magnum 3012 and the Microair Easy Start that it overloaded the 2800 VA Yamaha. Nor could the Magnum reliably handle the load by itself. It did start up once with this overload--but the load was 287 amps @ 12 volts (3444 watts @ 112 volts AC)

With folks going to higher voltage banks we may be better off speaking in watt-hours of storage.

Here is a chart for 100 amp-hours of storage.

@ 12 volts 1300 watt-hours
@ 24 volts 2600 watt-hours
@ 48 volts 5200 watt-hours

I suspect that 2oldman can safely draw 1c or 5200 watts on his (magnificent) battery bank. Since his stated maximum demand is 1300 the bank isn't even breaking a sweat.

100