question

kril avatar image
kril asked

Battery overcharge protection from MPPT

Greetings,

I have these devices:

1. MultiPlus-ii 24/3000/70-32

2. SmartSolar MPPT 250/60

3. Gerbo GX

4. Two Gel battery 200AH

Can you please help me with a short circuit how to connect these devices for such conditions:

1. When the mppt generates power - charge the battery to 100%, then use the power (mppt) to load the AC without draining the battery and over charge battery?

2. When mppt is not generating power, use only AC?

3. If there is no AC grid, use mppt if exist and then battery?

4. If AC grid exist and mppt not exist - charge batteries from inverter to 100%?

I'm not sure if it's possible, that's why I want to find the best way to connect all these devices.

Thanks in advance for your help.

Multiplus-IIMPPT SmartSolar
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3 Answers
kevgermany avatar image
kevgermany answered ·

The key is the Cerbo and turning on DVCC in the settings.

The system will perform as you expect, but for better control a smart shunt or BMV would help.

Sorry I'm not able to produce a circuit diagram for you. But the product manuals have good ones.


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cardy01 avatar image
cardy01 answered ·

I can only echo the comment about system diagrams - there are some excellent schematics in the support section of the Victron site which will guide you to connect things together.

With regard to your specific questions:

1. When the mppt generates power - charge the battery to 100%, then use the power (mppt) to load the AC without draining the battery and over charge battery?

The first part of your question is default behaviour, the second part requires some additional work, there are some options one of which is to implement AC Ignore in the inverter.

2. When mppt is not generating power, use only AC?

Again, this is default behaviour.

3. If there is no AC grid, use mppt if exist and then battery?

Without grid the inverter will be fed by the MPPT and battery but not one then the other.

4. If AC grid exist and mppt not exist - charge batteries from inverter to 100%?

I think this is the same as your #2?

I'm not sure if it's possible, that's why I want to find the best way to connect all these devices.

This link will help steer you in the right direction .....

https://www.victronenergy.com/live/ve.bus:solar-and-wind-priority

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kril avatar image
kril answered ·

Hello.

After reading the documentation I think, the connection should be like this

41082-mp2.png


Can you confirm it?

My main goal is to protect the battery, when AC grid and MPPT are available.

If everything is correct I will buy the SmartShunt and get back with setting questions.

Thanks.


41082-mp2.png (153.5 KiB)
2 comments
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kevgermany avatar image kevgermany ♦♦ commented ·
You're missing a connection from the shunt to the Cerbo, but otherwise looks good. I'm assuming you will put a DC busbar/ for neg and fusebox for positive on the outputs from the MPPT. Might be a good idea to power the Cerbo from there as well.
1 Like 1 ·
kril avatar image kril kevgermany ♦♦ commented ·

Is this cable used for connection shunt to the cerbo? https://www.victronenergy.com/cables/ve.direct.cable

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