Hello, just connected the mppt 150/45 to a set of 16 lifepo4 batteries. As soon as I connected smoke came out the unit. AND a the connection sbort cut. No panels connected, just batteries and EVever sinus inverter 48/220.
Any ideas? See picture
asked
Mmpt 150/45 release a lot of smoke
Have you put a voltmeter on the red and black to verify the other ends are actually connected to + and -? That unit is potted, so no repair possible.
Precisely! Although there is a reverse polarity protection fuse in the unit, it is not user serviceable.
Thanks for the reply. The unit was correctly connected. Even tested before connecting. Just blows my mind what caused it.
@Bluewally, how did you test the unit prior to connecting it? Do you mean that you connected it to a tabletop power supply, or you had previously connected it to this bank of batteries, or?
I would like to see some photos of the surrounding area as well; I see a large number of cables (including at least one bare end) running in various directions so I'd really like to be able to see the entire installation that shows a continuous connection from the battery bank to the MPPT.
Hello Justin, thanks for asking more questions. Here is a photo of the layout. The cable below is for solor panels but they are not installed yet. It was just a trial connecting batteries, charger and inverter. 
What's the voltage across the battery bank? I see 16 batteries, but what voltage and how are they connected?
I count 14 cells, and the links are clearly shown on top of the cells.
Note that the positive lead for both the mppt and inverter wont reach the right hand side of the battery.
Look like series to me but I can't see clearly enough to be sure? If I'm wrong, please educate me! :)
Yes series, have a look at the terminals closest to the camera, a link on every second cell.
Have a look at the last 4 cells, you can see the cell links on the terminals farthest from the camera. Note the black cable just above the last RH cell.
Note the burn mark on the LH cell.
Looks like a battery made out of Calb180ah cells.
Hi @Bluewally
That's obviously not good, please contact your dealer for a replacement.
What kind of fuse / fuse size was between the battery and the controller?
Btw. if it was connected in reverse polarity, the internal fuse should blow immediately, so no smoke.
Has the unit ever been powered up with any other battery? Battery voltage sense is automatic...once. So if the MPPT was connected to a 12VDC battery for testing and then reconnected to a 48VDC battery smoke may ensue.
Hi @CharlieJ
it should only alarm 'battery high voltage' nothing else.
OK. That eliminates that action as to why the magic smoke escaped from the box.
