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Planned upgrade to military solar trailer.

Supervstech

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My customer has this military solar trailer I installed 4 BYD used batteries into.
He then went with eight 100Ah 12V batteries, and he asked me if this would allow him to operate 50Amp loads off his 3500W inverters.
I explained it would only allow what he has to operate for longer times.

So I’m now planning to replace his three 3500W 24V inverters with a pair of 6500W growatts/MPP units. This would bump the batteries up to 48V, and his array voltage to 250V max, from 150V, and go from two 50Amp charge controllers to four 80A controllers.
This should allow him to attach FAR more solar to the trailer, and he has PLENTY of panels to max out his charging.

The units also have Wi-Fi built in!
So he can get status and usage reports etc.

The wiring is MASSIVE in the trailer, so no issues there. I am concerned about the fuses installed. They appear to be ANL fuses, so I think they should be upgraded to T-class.

Anybody think of any hurdles I should consider before ordering all this?
 
I was calculating the C rate draw from the bank, with the three 3500VA inverters battery load was maxed around 440A, going to two 6500VA inverters at 48(51.2)V changes the max amps to around 260A… I will basically have 600Ah installed, so it’ll be a breeze for the bank…

Next year he might upgrade to rack mount batteries, but budget constraints what they are, this will handle his needs and give him the ability to pull heavier loads.
 
if bump to 48v system, gentle nudge for T-class fuse

fuses AIC go down with increase of voltage

ANL sounds like already could arc given specs and a kickoff short? just amateur gut thinking. unaware of cell specs.

unaware of which 100Ah cell/specs, some are rated for 2C continuous discharge, so ~0.5C breeze likely (with 300Ah class, 0.5C heat accumulation etc..)

cool and good luck
 
Any thoughts?

e-needpics.gif
 
I'm thinking I can simply reverse the order of one side of the 12V bank arranged as 24v each to bussbars, then tie them together as 48V...
And do similar with the 24v byd sets.
Change the fuses in the holder to T-class 300's and wire it all up.
Fun.
 
Are your thoughts to run it as 2 independent systems in parallel or combine it all into one total system?

6500 watts being pulled from a 48 volt pack is a lot to sustain from a 100 amp-hr battery.

I normally use Lifelines and that discharge rate is higher than they list on their charts. (basically the top of their chart is 1 C).

So I guess if you make it the equivalent of a 2P 4S pack feeding a common bus bar arrangement, and then that feeds both inverters, it is enough to keep up with 1 inverter going full tilt and the other running light loads.

If you go to a GPL- 31 HT (just slightly larger but taller) it might be viable based on the info in the technical manual.

4 each of the 4Ds are a better technical fit for the discharge rate but I am not sure if that would fit unless you stack them.

In a perfect world, there would be 8 batteries for each inverter, so 16 total to deal with those rates and not sag much.

__________

I don't have any experience with the growatt setup. The highest solar panel voltage that I have setup is only ~ 110 Vmp using the conventional midnight solar breakers.
 
Last edited:
Are your thoughts to run it as 2 independent systems in parallel or combine it all into one total system?

6500 watts being pulled from a 48 volt pack is a lot to sustain from a 100 amp-hr battery.

I normally use Lifelines and that discharge rate is higher than they list on their charts. (basically the top of their chart is 1 C).

So I guess if you make it the equivalent of a 2P 4S pack feeding a common bus bar arrangement, and then that feeds both inverters, it is enough to keep up with 1 inverter going full tilt and the other running light loads.

If you go to a GPL- 31 HT (just slightly larger but taller) it might be viable based on the info in the technical manual.

4 each of the 4Ds are a better technical fit for the discharge rate but I am not sure if that would fit unless you stack them.

In a perfect world, there would be 8 batteries for each inverter, so 16 total to deal with those rates and not sag much.

__________

I don't have any experience with the growatt setup. The highest solar panel voltage that I have setup is only ~ 110 Vmp using the conventional midnight solar breakers.
Sorry, I guess I wasn’t clear on this. The trailer currently has FOUR 24V 200Ah banks tied in, and I added EIGHT 100Ah 12V batteries that I will be configuring to 48V, so I’m pulling the inverters off 600Ah @48V…
 
So T class fuses for protection. Any breakers in there for routine maintenance or using another method?

Just curious.
 
No breakers currently…
It does have battery switches, and relays controlled by can bus control panel.
 
I wish I had something more to add. But I don’t

There’s a certain point outside/past my experience, knowledge, and- perhaps- skillset that makes me scared? and you’re definitely past that. 100A or 200A grid panel is the start of nervous; 200A DC battery output will weld some fairly thick steel.
What you are doing is enough to smelt that trailer and cast a new tractor!

I’m thinking a single application specific insurance policy with “additional insured” might be a way to protect yourself in the event of an uh-ohh that probably wouldn’t even be your fault.
 
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