Solar from MPPT goes to 0W when Absorbtion Charging

DIY
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1

Hi,

Have a 3 phase system setup with:
3x MultiPlus II 48V/5000/70.
1x MPPT Charger RS 450 / 200.
Cerbo GX
30kW battery bank Vision/Victron.
VECan Battery Shunt 1000 with Lynx Power and Distributor 1000.

Everything has been running perfect from day 1 (3-4 months operation as of now).

10kW Solar panels.

Have one issue that when charging batteries from the morning from example 70% to 100% via the solar panels, when battery bank reaches 100% and it goes into Absorbtion Charging the MPPT for a while sets PV power to 0W or a lower value than is actually available from the solar (this is randomly on each solar Array).
After a while when Absorbtion is finished = goes into Idle alle Arrays of PV come back to its normal W (for example 3000W / 2000W etc.).

Any reason for this as 30 min. to 1 hour of PV solar power seems to be lost (which could have been thrown back into the net) easily 5-6kwh of energy on a shiny day.

Did a FW update on the system so all is up to date. But same issue.

2

Its a problem because the batteries manage the chargers, they don’t care about your willing to sell energy.

So take the management of the MPPT from the Cerbo, set absorption lenght to 12h, they’ll feed the grid all day or as long as the sun shines on you.

3

Hi,

Batteries are “Iron-V LFP12-200EV-HBT”. So no communication goes to from the batteries.

Battery Monitor is set to Lynx Shunt 1000A VE.Can on VE.can.

Tia, Søren

4

Is the mppt controlled by the cerbo ?

5

If you mean DVCC, then no.

Please see attached pic.

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6

One possibility could be to enable DVCC (without BMS). Limit the charge current and see, this might work?!

Tia Søren

7

Sorry, I don’t trust 48V systems with 12V batteries, at least not without 3 balancers connected.

2 Likes
8

OK, so option could be to change the Lynx Shunt 1000 to the lynx Smart BMS 1000?

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9

@= not sure what you mean by this;
So take the management of the MPPT from the Cerbo, set absorption lenght to 12h, they’ll feed the grid all day or as long as the sun shines on you.

Can you elaborate?

10

I will second this. I have seen many destroyed batteries and problems 1-2 years in. Add balancers.

These are designed for victron batteries specifically. So are not a solution for you.