Switch off charge controller MPPT 100|50 when batteries are full

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steffenbrand2607 asked Sep 15, '23

Switch off charge controller MPPT 100|50 when batteries are full

Hello everybody,

I have a question regarding switching off the charging process of our MPPT 100|50.

We have a off-grid installation in a 24 V configuration. Around 800 Wp of solar modules and two batteries which will be charged during the whole day with 150 Ah of capacity. Our

The batteries are urgently needed at night and will be discharged around 10% during the night. In the morning there is still 90% of battery capacity available as we have a permanent AC load of around 20 W. At sunny days, the batteries are fully charged at around 10 to 11 am. The rest of the day, they are floated with around 1.10 to 1.20 A of charging current.

As the batteries were quite expensive, I want to extend their battery life, of course. So I asked whether it would be possible to swith off the charging process (MPPT100|50) during the day and switch it on againg 2 or 3 hours beforce sunset.

Would that be a good idea? If yes, how can that be implemented?

Thank you and best regards,

Steffen

MPPT Controllers battery charging switch

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Answer 1 · 2023-09-15T18:08:34Z

Alexandra answered · Sep 15, 2023 at 06:08 PM

@SteffenBrand2607

Are these lead acid batteries? Or lithium?

You can set the rebulk offset lower then it will not start a charge cycle again on the same day.

The other way is with a bmv for SOC switching or a GX for time based switching and the remote terminals on the mppt.

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Answer 2 · 2023-09-15T18:39:03Z

steffenbrand2607 answered · Sep 15, 2023 at 06:39 PM

Hi @Alexandra ,

Thank you for your quick answer.

These are AGM batteries so I would say lead acid.

How can I determine the rebulk offset? Which device? We have a MPPT, a BMV-700 and batteries abs-line trad12-150. I attached a photo of the installation.

For your second suggestion with the BMV or the GX. How is that done?

Thank you very much.

Steffen

img-7247.jpeg (4.4 MiB)

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