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siim avatar image
siim asked

Problem with a solar system

Hey! I have victron solar system on my van. Originally it was 420w panel, two 12 V batteries (24V) and mppt 75/10 controller and and inverter 24/1200. Solar system batteries were connected with car batteries with cyrix-ct. Everything was working nicely about 6 months and one day batteries were empty (don’t know the reason). Batteries were charged and after putting them back in the system there is no charging anymore. Controller stays constantly in float mode. I have disconnect the system and put it back together in right order(batteries first then panel) and nothing change. Now I got another controller mppt 100/20. This one stays in bulk mode the whole day even the batteries are fully charged in car repair shop and I think there is no charging because voltage is dropping. In the mornings the system is in internal error mode (blue and yellow are blinking). Only change what I have done in system is disconnecting the car batteries from car batteries.

Does anybody has some ideas what’s wrong?

I also have some questions about the system.

1. Should controller lights stay on when sun goes down? At the moment controller shuts down when sun sets and even the Bluetooth don’t work!

2. Why the panel shows 1w even with a direct sun and there are no current when controller is in bulk mode?

Thanks

Siim

MPPT Controllers
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2 Answers
Rob Fijn avatar image
Rob Fijn answered ·

Hello Siim,
The MPPT light should stay on and you should be able to connect to the Blue Tooth.

I would have the following questions:

- if there is a fuse in the DC lines, you should check this. Measure this.

- Measure the DC voltage on different points. If it is Higher or Lower at curtain point(s), found out the reason why and check it this is right.

To me it looks like you are missing one lines to the battery (positive or negative). The MPPT comes 'alive' when the sun comes up.... but it should be ON all the time powered from the battery

I hope this helps. Let us know what you find.


Best regards,

Rob

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siim avatar image
siim answered ·

Thanks Rob!

By measuring the voltages I found out that the mppt 75/10 fuse was cooked even it looked like okey. Now the system is working but still don’t have an idea why mppt 100/20 doesn’t work! If I have more time I will find out!

Thanks one more time!

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