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createthis asked

SmartSolar MPPT 150/70-Tr Err 40

I accidentally connected my battery to my MPPT 150/70-Tr's PV input and my PV input to the Battery connection yesterday. I left it that way overnight. I woke up this morning to a flashing Error 40 code. The user manual says:

Error 40 - PV Input failed to shutdown If the charger is unable to turn off the PV input, it will go into a safe mode in order to protect the battery from over-charging or having a high voltage on the battery terminals. In order to do that, the charger will stop charging and disconnect its own output. The charger will become faulty.

Is this unit toast now, or is there a way to reset it?

MPPT SmartSolar
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michelg answered ·

Hi, try to disconnect everything, then reconnect the battery bank first at the correct connectors, then the PVs.

It may work. If not, then your mppt is probably toasted.

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createthis avatar image createthis commented ·
Same result. Err 40. Are these units repairable, or is it just a $600 brick now?
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kevgermany avatar image kevgermany ♦♦ createthis commented ·
Contact your dealer. Might be an easy fix, but needs to be checkedrepaired properly.
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createthis avatar image createthis kevgermany ♦♦ commented ·
Purchased through amazon. I've filled out the distributor locator form on Victron's website. We'll see what happens.


My understanding is that these units are filled with some sort of anti-vibration compound (epoxy or something), so if it isn't a software issue, I suspect it's bricked.

I'm just trying to wrap my head around why this would break the electronics. I'm not an electrical engineer (I'm a software engineer), so I appreciate that this can be beyond my understanding, but the PV input is rated for 150 volts and 70 amps on this unit. My battery is only 13 volts. I don't understand why this would fry the unit.

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seb71 avatar image seb71 createthis commented ·

A battery as a power source (current source) is very different than a PV panel/array. For example, shorting the leads of a PV panel has very different results than shorting the battery terminals (don't try this on purpose).


At least the polarity was correct?


When the PV was connected to the battery terminals, was it during the day? The PV array voltage can be way higher than the battery voltage.


Any solar charger should not be connected to a PV, without a battery connection. During the night, with your swapped connections, only the PV terminals had a power source connected (and worse, it was a battery).


So multiple potential causes for solar charger damage.

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