Multiplus 12/1600/70 not charging at configured DVCC

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llubi asked Jun 20, '23

Multiplus 12/1600/70 not charging at configured DVCC

Hi all,

I have the multi connected to Grid, selected 4A max from 220V, DVCC with max. limited amps at 50, and checked the configuration with VE Configure and everything looks normal (battery monitor disconnected, lifepo battery configured, voltages OK,...).
I'm using 123BMS and the limit for charge is at 600A (lifepo 600Ah).

When I connect to the grid, limited at 50A, the multi starts charging at 50A for 5 minutes, then it goes to around 35A. Checked also temperatures, at multi, battery, bms, busbar... highest are the bms at 37ºC, battery is at 33 for example.

Any ideas?

Thanks!

battery charging multiplus ve.bus

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Answer 1 · 2023-06-21T18:29:29Z

Alexandra answered · Jun 21, 2023 at 06:29 PM

@llubi

If your battery is at 37°C it is likely your ambient temps are high.

The charge rate dropping is most likely because of inverter temperature derating.

How big are your DC cables and AC input cables? Length of run to and from sources?

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llubi commented · Jun 21, 2023 at 07:12 PM

Thanks @Alexandra !

I did not checked the ambient temperature, it should be around 25C, has van was in an underground parking, the 37 degrees I think it’s because the mosfet work at the BMS boards.

AC wiring is around 4 meters, 3 x 1,5mm. Running at 220V without limits on the van or the building.

DC is from multi to a busbar (cooper bar 25x5mm), around 1 meter each wire 70mm2, and from busbar to 2 x 300Ah lifepo also using 70mm2 wire, 1-1.5m each wire.

Any other idea?

Thanks!

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Alexandra ♦ llubi commented · Jun 21, 2023 at 07:43 PM

and your inverter has good cooling space around it? When i was referring to derating i meant internal temps of the inverter which and not going to be at ambient.

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