question

bodhiray avatar image
bodhiray asked

Cooked Controller?

I have had a MPPT 250/100 charging 48v SLA batteries for 2 years now working excellent. We recently upgraded to Li batteries. During the switch out I disconnected battery and pv. I reconfigured the charging parameters for the new pack chemistry. When I reconnected the MPPT to battery I did it backwards — last thing I did was turn on battery at disconnect between MPPT and Battery — BLUE FLASH — sparks, smoke the whole nine wafted out of the MPPT. Trouble shooting I found that my on/off switch at PV combiner box is not putting energy through in either on or off position. Any advice to trouble shoot further is much obliged.

I do have a standby 150/100 MPPT I can put in it’s place but this requires reconfiguring my PV and I would like to avoid that. Will do it thought if I’ve reduced the 250/100 to a paper weight...

MPPT Controllersmppt charging
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2 Answers
seb71 avatar image
seb71 answered ·

It's dead, Jim.

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Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @bodhiray,

Sorry to tell you, connecting the MPPT with reverse polarity to the battery is one of the few near certain ways to destroy it.

Another is connecting it to a PV array with a voltage higher than the maximum.

Those are the 2 most common installation faults that will destroy a Victron MPPT that I see.

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bodhiray avatar image bodhiray commented ·

So far as I understand the only “backwards” part of the installation was that I connected the battery second as in after the PV connection. Polarity is correct and well under voltage.

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Guy Stewart (Victron Community Manager) avatar image Guy Stewart (Victron Community Manager) ♦♦ bodhiray commented ·

Ah, I misunderstood your meaning of 'backwards' to mean reverse polarity, rather than as you have you have just explained it to mean 'correct polarity, but after connecting PV'. That should not normally destroy the MPPT.

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bodhiray avatar image bodhiray Guy Stewart (Victron Community Manager) ♦♦ commented ·

Any further thoughts on this? I’ve sent a support request to the distributor this unit was purchased and am waiting to hear back. Maybe a broad question is more appropriate for figuring out what happened. Why is it necessary to connect battery first, then pv?

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MPPT Product Page

MPPT Error codes

MPPT 150/60 up to 250/70 Manual

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