Leaving boat unattended with solar

[Sarge17]

I have a 12 Volt, 5 Watt panel that is always connected to the battery bank. The boat is in FL and I leave the boat for a month or so at a time. The batteries are always fully charged when I return. I have a 45 Watt panel I use if I need more power when sailing.

[tinkrman69]

Batteries loose a 1/4 amp a day to the air. just sitting, even when not hooked to anything. the lower the state of charge the more you'll loose and higher the humidity will cause more loss too. It can get up to 1/2 an amp. So there will always be room for some charge. Make sure you have plenty air room/flow around the heat sink on the charge controller, as when the panels are putting out more than is needed the extra amperage will get dissipated through heat.

on another boat I had with wind and solar I used a load diverter type controller and ran the load to a heating element in a small tank for hot water. I had fairly hot water most of the time, in the southern trades.

[Xthewater]

Might want to worry about raccoons sneaking aboard.

[DMCantor]

We have 350 watts of solar and a 1050 AH AGM house bank. With a Bluesky 3024iL, and with only the bilge pump active, we see several hours a day with voltages well above the battery float voltage. I have often wondered if this is OK, but have chosen to pull the fuse when we are away from the boat. The folks that do caretaking for us put the fuse back in for a day or two periodically to keep the batteries topped up. This seems to work OK.

David
s/v Callisto

[SV Bacchus]

Originally Posted by DMCantor

We have 350 watts of solar and a 1050 AH AGM house bank. With a Bluesky 3024iL, and with only the bilge pump active, we see several hours a day with voltages well above the battery float voltage. I have often wondered if this is OK, but have chosen to pull the fuse when we are away from the boat. The folks that do caretaking for us put the fuse back in for a day or two periodically to keep the batteries topped up. This seems to work OK.

David
s/v Callisto

No expert here, I am gleaning all the info I can. After reading the posts of others I wonder why you pull the fuse? Have you had a bad experience we could all learn from?

Also, humid Florida here, it seems those extra volts could be put to good use running a dehumidifier. Which, depending on where it drains, may run the bilge pump every once in a while.

If you are gone for a month or two, would a dehumidifier generate enough fluid to flood a vessel to the point of damaging your sole flooring in that time period if the bilge pump quit?