question

kdrozda avatar image

MPPT 100/20 FUSE

Hi everyone. I have SmartSolar MPPT 100/20. And I have two questions: should I put a fuse between the controller and the battery? I know that there is already a 25A fuse in the device, but I do not know which line is protected by PV - MPPT or MPPT - BATTERY or maybe both or just LOAD? And second, is it true that if I disconnect the battery with solar panels connected, I will damage the charge controller? Regards Chris

mppt smart solar
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
seb71 avatar image
seb71 answered ·
should I put a fuse between the controller and the battery?

Yes. Size it to protect the wire.

is it true that if I disconnect the battery with solar panels connected, I will damage the charge controller?

You should avoid doing this. The charger might be damaged (so this "might be damaged" means that it can also might be fine).

5 comments
2 |3000 characters needed characters left characters exceeded

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Thanks for the answer, can you tell me what fuse value ... 30A?

What wire size (cross section) you will use betwen the battery and the MPPT charger?

That's the maximum it can take, right?

And I assume it's copper.

Use a 25A fuse.

6mm2 - yes it is max.
The last question, maybe stupid - if the battery also receives electricity from the alternator (of course, through the starter battery and the cyrix 120A), it will not damage the MPPT connected to the battery? Cyrix has a 120A fuse, should I somehow separate the charging system and disconnect the solar system while the engine is running?