question

han solo avatar image
han solo asked

Victron EasySolar-II 48/3000/35-32 MPPT 250/70 GX battery High voltage efficency

I've got an Victron EasySolar-II 48/3000/35-32 MPPT 250/70 GX

Inverter spec says up to 66 Volt, MPPT spec does not say max voltage, but you can set it to 65 Volt

however I'm not able to get the MPPT to charge the battery over 64 Volt

Battery is 24 Nissan Leaf Gen2 modules, 8s3p with a 123smartbms

16S3P

Nominal V: 3,75V

Recommended working range: 3 to 4,1 V

Balance 4,1V

Recommended BMS settings: 2,9 to 4,2V

Capacity when new: 62 Ah

84% remaining capacity: 52Ah (x3 cells 156Ah)

Battery capacity: 9,36kWh

Enter 85% in BMS: 7,95kWh

Cell minimum 3V

Shutdown: 3 x 16 = 48 V


I'm wondering if both Inverter and MPPT are less efficient running at such "high" voltage

as they are designed for 48 Volt.


1661778368597.png

MPPT ControllersMultiplus-IIEasySolar All-in-One
1661778368597.png (68.4 KiB)
2 comments
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han solo avatar image han solo commented ·

Just to clarify my question regarding efficiency, it does not matter if the PV charger shows 2800 W or 1800 W, battery is still idle and AC loads stays the same. so up to 1000 W is just disappearing.


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Mike Dorsett avatar image Mike Dorsett commented ·
try dropping to 7 series to get a better voltage match..
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1 Answer
JohnC avatar image
JohnC answered ·

Hi @han solo

Where is that data in the Battery tile coming from? I suspect the bms, and it's not showing Amps, so maybe a compatibility issue there?

If the SOC is anywhere near correct, the batts are well down in charge. And this would be the reason you're not reaching the expected target V.

Give them a decent charge. That's a fairly hefty load, and it would help if you could avoid that for a while..

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