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createthis avatar image
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 avatar image
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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createthis avatar image createthis seb71 commented ·

Yes, the polarity was correct. It's a portable system and I use anderson connectors for the disconnects. I just swapped them by accident after charging from my grid adapter.

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kevgermany avatar image kevgermany ♦♦ createthis commented ·
Maybe rewire them so you can't do it. With this sort of thing I'd have a male on the input/solar side of the mppt and a female on the output side.
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createthis avatar image createthis kevgermany ♦♦ commented ·
Anderson connectors are genderless, but yes, clearly I need to change something so that this can't happen again, particularly if it bricked the controller. Still trying to figure out if the controller is hardware failed or software locked.
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seb71 avatar image seb71 createthis commented ·

Usually the battery wires are much thicker than PV wires, so easy to tell which is which. Wasn't this true in your case?


For a portable setup, a 150/70 seems oversized. Depending on what someone considers portable.

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createthis avatar image createthis seb71 commented ·

a62d983b-f233-40a1-a486-eb4bc8ca429c.jpegMy portable setup has external 100ah 12v batteries connected to the “head unit” via 4/0 cable and Anderson forklift battery connectors. The Victron mppt controller is just hanging out on top of the head unit at the moment and has two short 6 awg pig tails. Internally to the head unit there are 600 amp bus bars and blue sea systems breakers. Initially I didn’t design the head unit to use this victron charge controller. It was an afterthought because I picked up a group of modules with characteristics different from my first group of modules.


Clearly I need to redesign this. I like the victron controller because it has lower parasitic loss than my midnite classic. I bought the Victron MPPT controller with the goal of eventually replacing the Midnite Classic, or at least fully integrating it into the head unit. I just never got around to it.

Yes, it's overkill. I only need a charge controller capable of 48v solar input and 30 amps with the current panel I'm using. I like to keep the voltages at safe levels on my portable setup just in case I do something stupid, which clearly, I did.

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seb71 avatar image seb71 createthis commented ·

And do you have a 1000W "portable" PV array?


I ask because when used with a 12V battery, a 150/70 can use a 1000W PV array (or even slightly larger, to account for cloudy weather or less than optimal panel orientation).


If your PV array is not close to this 1000W and your 150/70 is dead, you can buy a smaller (and cheaper) replacement.

On the other hand, it's true that if the solar charger cooling is less than adequate, an oversized solar charger is better.

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createthis avatar image createthis seb71 commented ·

Yes, I have two 400W panels made from 4x 100W modules each. Each panel has a different charge controller (midnite classic for one, victron for the other). I also have another 400W panel that I just bought a few weeks ago, waiting for a home. I could combine two of them into 800W since they are the same type of panel, electrically. Then I'd have an 800W panel and a 400W panel, for 1200W total.


My issue is that since everything is indeed portable, I don't want to exceed 48V of solar input, just so I don't accidentally shock someone if I screw something up. I think I'm at the point where I need to break everything down into smaller separate systems, or else just commit to having a non-portable system.


Yes, if I decide to keep the system as-is, I can use a much smaller charge controller for this one 400W panel.

I strongly suspect the 150/70 is just software locked. I'm still able to connect via the bluetooth app and I still see accurate PV input and battery voltages. It just refuses to go into charge mode.

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kevgermany avatar image kevgermany ♦♦ createthis commented ·
Never used them. Maybe colour code?
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createthis avatar image createthis kevgermany ♦♦ commented ·
I was thinking the same if I can get the charger back online. Maybe some colored electrical tape on the PV side connectors or a couple of ranger bands or something.
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