Molly
Senior Member
- Joined
- May 2, 2018
- Messages
- 127
- Location
- USA
- Vessel Name
- La Bella Vita
- Vessel Make
- 2006 Mainship 34T
I have a 2006 Mainship 34T, twin screw.
It's my first full season with the boat. I put the boat back in in Oct of 2018. The batteries were cooked. I attributed that to the PO's lack of concern for the water level in the batteries. I added 3 gallons to 4 batteries. 3 8D's and 1 #27
The 8D's are a combination starting bank plus the house bank. he 27 is dedicated to the genny.
They are all brand spanking new. Just did a direct replacement. Set up as is.
The batteries will discharge down to 12.4 vdc in 1 hour from 13.9 vdc. I turned off the battery switches, same thing.
I disconnected the battery terminals, after a full charge. They dropped to 12.65 vdc after 4 hrs. and 48 hrs later they were 12.55 vdc. I think that's fine.
Previous boats, I could let sit, with everything turned off, for 2 or 3 weeks. Go to thew boat and start her right up. On the hook, I would get 24 hrs without worrying. That's with fridge, lights, fresh water, stereo, the usual stuff. The last boat I had a solar panel and would go 2 days.
This boat, I have to start the genny 2 or 3 times each day to keep things OK. If I leave the boat for 3 days, I can't start it. I have to plug in to charge up the batteries.
There is a battery isolator, but it's only on the one engine with 2 8D's. The other engine has an 8D, no isolator.
The genny has a completely separate battery. Tied into NOTHING.
Why would ALL the batteries discharge? The only system that ties the entire boat together is the bonding system. That is factory installed. The only after market items are the battery isolator and a separate 110v charger for the genny battery, (not hooked up to the charging system, only handles 3 batteries)
Seems to me that the system is just dumping power through a ground?
HELP ME!!!!!! (said the fly in the web)
It's my first full season with the boat. I put the boat back in in Oct of 2018. The batteries were cooked. I attributed that to the PO's lack of concern for the water level in the batteries. I added 3 gallons to 4 batteries. 3 8D's and 1 #27
The 8D's are a combination starting bank plus the house bank. he 27 is dedicated to the genny.
They are all brand spanking new. Just did a direct replacement. Set up as is.
The batteries will discharge down to 12.4 vdc in 1 hour from 13.9 vdc. I turned off the battery switches, same thing.
I disconnected the battery terminals, after a full charge. They dropped to 12.65 vdc after 4 hrs. and 48 hrs later they were 12.55 vdc. I think that's fine.
Previous boats, I could let sit, with everything turned off, for 2 or 3 weeks. Go to thew boat and start her right up. On the hook, I would get 24 hrs without worrying. That's with fridge, lights, fresh water, stereo, the usual stuff. The last boat I had a solar panel and would go 2 days.
This boat, I have to start the genny 2 or 3 times each day to keep things OK. If I leave the boat for 3 days, I can't start it. I have to plug in to charge up the batteries.
There is a battery isolator, but it's only on the one engine with 2 8D's. The other engine has an 8D, no isolator.
The genny has a completely separate battery. Tied into NOTHING.
Why would ALL the batteries discharge? The only system that ties the entire boat together is the bonding system. That is factory installed. The only after market items are the battery isolator and a separate 110v charger for the genny battery, (not hooked up to the charging system, only handles 3 batteries)
Seems to me that the system is just dumping power through a ground?
HELP ME!!!!!! (said the fly in the web)