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rexerito avatar image
rexerito asked

MPPT only 4w charging on 600w solar

Just installed MPPT150/60 Tr charge controller replacing a Jaboni 30 amp. I have two 300w panels in series. I only see 4 to 5w coming from the solar. Two questions, first why don’t I see more coming from the panels my 2 battle born 100ah batteries are at 60% charge? I would think with two 300w panels I would see more? It's noon and the sky is clear. Second, when I installed the charge controller, it told me to install batteries first, then solar. Unit wouldn't turn on just with batteries. Is this normal? Thanks for the help, I'm completely new to this.

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MPPT Controllers
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2 Answers
Alexandra avatar image
Alexandra answered ·

@Rexerito

The most common cause is a reverse polarity connection.

The unit should have switched on when you connected the battery though.

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rexerito avatar image rexerito commented ·

Thanks, how do I fix the polarity issue?

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Matthias Lange - DE avatar image Matthias Lange - DE ♦ commented ·

A reverse PV connection will show 0V PV.

A reverse battery connection can/will damage the MPPT.

With just the battery the MPPT should turn on so first check if the battery connection and if there is a blown fuse, open switch or loose connection between the MPPT and the battery.

Disconnect PV and measure the voltage at the battery connection of the MPPT.

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rexerito avatar image
rexerito answered ·

Thank you. I found a blown fuse next to the battery. This solved my issue.

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Alexandra avatar image Alexandra ♦ commented ·

@Rexerito

Glad you found the issue.

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