question

js-solartech-india-pvt-ltd avatar image
js-solartech-india-pvt-ltd asked

Multplus ll charge battery very slow and goes on Idle mode before 100% charge

jerom-1.jpgjerom.jpg

battery charging
jerom.jpg (42.5 KiB)
jerom-1.jpg (56.6 KiB)
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
JohnC avatar image
JohnC answered ·

Hi @J.S. Solartech India Pvt. Ltd.

Your Multi isn't actually doing the charging here, it's the mppt. And it's showing Float mode, with little current. Your batteries are effectively full. And the shown SOC will be incorrect.

Presuming you have pb batteries, the SOC calculation within the Multi can be made fairly accurate with the full-on charge from an ac supply. But with solar it can be unreliable. If you wish to persevere with it, try tuning it. Maybe the 'bulk finished' to 95% and 'efficiency' to 0.85 as a starter.

In the end though you can reliably judge when they're full by looking at how much charge they can accept at the mppt Float V. I don't know your batts, but with that 200Ah they'll be done at maybe 1 to 2A. Watch it regularly and adjust as above to see if you can improve the shown SOC.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.