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Hooking up a MPPT charge controller to a battery

circus

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The instructions stressed hooking up the battery before hooking up the PV panels. Fine. Only thing is, there's a fuse between the mppt and the battery. What would happen to the mppt if the fuse was tripped (no battery) and the PV panels were producing, say, 700 watts? Purely hypothetical
 
Usually the MPPT survives a battery disconnect. Since the purpose of the fuse is to prevent the cable and/or the MPPT controller from catching fire and burning you house/RV/boat/shack, loosing the solar controller is a good trade off.

Mike
 
Generally the battery is hooked up first for multi voltage MPPT’s so it knows the proper voltage to output.

And don’t worry too much about your MPPT in this case since the fuse is needed as noted above.

These aren’t some frail namby pamby things ?. See here :

 
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Generally the battery is hooked up first for multi voltage MPPT’s so it knows the proper voltage to output.
Yes and I consider the battery voltage sensing a necessity for original setup, but I think its best to specify your battery voltage in permanent settings (instead of AUTO) if it is possible (and as soon as possible).
 
Yes and I consider the battery voltage sensing a necessity for original setup, but I think its best to specify your battery voltage in permanent settings (instead of AUTO) if it is possible (and as soon as possible).
I have a similar question. The negative connection of my charge controller goes through the BMS. If the BMS shuts down the system I would think the charge controller is no longer connected to the battery. If I specify the battery voltage in permanent settings would that take care of the problem of the charge controller still being connected to the solar panels. The charge controller setting show the voltage of my batteries but I didn't set it so I don't know if it is permanent or just reading what the batteries are. I have a Victron 150/45-Tr
 
would that take care of the problem of the charge controller still being connected to the solar panels.
This was a hot topic about a year ago. Short answer is not it does not solve that problem directly.
The long answer is that SCC's were not being destroyed as the manufacturers were warning: Will even posted a video where he was actually trying to get all of his SCCs to self destruct by disconnecting the batteries with solar attached. (thread was something like: "i cannot destroy my SCC's").

EDIT: its actually the link in post #3.

So yes, its good to heed mfg warnings on NOT connecting batteries first and disconnecting batteries last. But when it happens in the wild, its not the certain doom fortunately.

On a related not, i had a cheapie blue PWM SCC momentarily/accidentally lose contact with a battery while connected to solar. It reset the voltage, perhaps to match the solar panel (?) and started charging at 24V. Fortunately I was watching as it got up to 15V and avoided disaster. Have since specified battery voltage in settings whenever possible.
 
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