question

alan-falck avatar image
alan-falck asked

Multiplus II 5kVA Split Phase ESS unstable

Product 2 x MultiPlus-II 48/5000/70-48 (one GX)c0619ab2998e_inst_ttyS3_Interfaces_Mk2_Tunnel (2).zip

Firmware version 500

Product id 2623

VE.Bus connection VE.Bus

Hardware configuration Two units configured as split-phase

VRM instance 275

2 x Pylon UP5000 4.8kWh Li-Ion Solar Battery 48V (Lynx Power Parallel setup balanced cables etc)


Hi, I'm running 2 x 5kVA Multis (one GX) in split-phase mode, all working fine until I enable ESS.

As soon as I add ESS (to both Multi's) the system crashes IE Low Battery Errors, (Error code: #67 - No BMS) and one of the Pylontech's seems to go offline (no power LED).

If I revert to no Assistants all works fine. One observation is the battery capacity reports 50% of the total during charge & discharge. I have copied identical ESS setups to both Multis and set 2x 200Ah on each. I've spoken to many experienced installed and tried & applied all their suggestions.

Any Ideas

A


ESS
c0619ab2998e-inst-ttys3-interfaces-mk2-tunnel-2.zip (1.5 KiB)
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2 Answers
nickdb avatar image
nickdb answered ·

Those batteries are 50A each which is too small for that combo. It’s likely the bms is taking exception to what is being asked from it. Would need way more info to take a more informed stab at it.

Do both batteries report the same charge levels?

What is the details tab showing for the battery on the GX?

They are 100AH batteries, not 200 each.

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alan-falck avatar image
alan-falck answered ·

Hi Nick, I appreciate batteries may be a bit on the small side, but how come there are no issues at all, no overload, and no low batt alarms when ESS is removed?

Yes, both battery the same charge levels.

Details as below

1676040557762.png

I set up ESS capacity as 200AH, should this be 100AH on each Multi on each ESS instance?

Could it be the Multis are only seeing one battery capacity?

Thanks


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