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sea avatar image
sea asked

HOW TO USE GRID TO CHARGE BATTERY AS BACKUP ONLY WITHOUT BACKFEED

Looking at a offgrid design in a suburban grid situation using a MultiPlus II or Quattro with a AC coupled Inverter to maximize efficiency and using 3 x 15kw batteries ( design is a work in progress )

battery charging
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matt1309 avatar image matt1309 commented ·

Absolute 0 backfeed look into AC Ignore assistant. Otherwise look into ESS system.

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3 Answers
ejrossouw avatar image
ejrossouw answered ·

@s.e.a You have to power all loads from the ACOUT as using ACIN and e.g. ESS requires synchronising with the grid to feed into the household supply to serve the loads. Adjusting the grid setpoint will allow you to control how much and what to do with excess. Not sending excess to the grid in an ESS does not make it off-grid as many wrongly believe.

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Duivert NL avatar image
Duivert NL answered ·

ESS also will always feed some back to grid to balance

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dangermouse avatar image
dangermouse answered ·

If you have a cerbo then use the relay output to connect to the Aux of the multiplus.

Program the multiplus to use the general flag to ignore AC in.

Use the generator start stop function of the Cerbo to control the relay

You can then set times for the AC to be activated on the cerbo, this gives you a great deal of control over the input. You can set periodic run times if you want to run it at night for instance, or run it when it reaches a certain SOC. You can also set quiet times to ensure it wont activate during the day when you have sun.


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