question

anselmus avatar image
anselmus asked

Smart Solar MPPT 100/15 long wire to battery and voltage drop compensation

I'm about to use controller to charge agm battery on my fishing boat. The battery is powering electrical motor. Panel and controller are on land so the wire between the Smart Solar and battery is about 4 meters (12 foot) long. I'm about to use 6mm2 wire. Is there going to be problems due voltage loss? Is there something I could do mitigate the effect? I used calculator to calculate the voltage drop should be about 0.35v. Can I set offset to the controller so the voltage at the battery end would be sufficient?

MPPT Controllerswiring
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

1 Answer
wkirby avatar image
wkirby answered ·

It depends how many Amps that 0.35V drop is apparent.
If that is the Voltage drop at 15A, then it's not so bad, as the battery goes through absorb stage and the current gets less, the Voltage drop will be a lot less and diminish to be insignificant.

The only way to limit Voltage drop is to use heavier guage wires.

2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

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

anselmus avatar image anselmus commented ·

Thank you! I should be ok then.

0 Likes 0 ·
Matthias Lange - DE avatar image Matthias Lange - DE ♦ anselmus commented ·

You can use the Smart Battery Sense to send the accurate battery voltage/temperature to the MPPT.

https://www.victronenergy.com/accessories/smart-battery-sense

0 Likes 0 ·