Since taking ownership of First Light 4 years ago, I have stored the batteries onboard after giving them a final charge and water level check. (They are lead acid). For winter storage, I always disconnected both the ground and positive cables.
This winter season, the boat yard has me just feet away from the nearest electrical outlet. I'm tempted to leave the boat connected to shore power. After all, the boat is designed to sit through the summer plugged in, and I'm sure the PO left it plugged in year round when it was in Florida. I did shut off all the ac/dc breakers with exception of the shore power charger- which shows virtually 0 voltage drain with the batteries topped off. I have a xantrex battery monitor, so there is a tiny drain. Are there any potential problems doing this?
I will verify it's OK with the boat yard and doesn't violate any insurance clauses.
Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B
Two years ago, I boiled off much of the water when leaving the batteries charging. I no longer leave the boat unattended when charging. I leave the batteries on the boat and check them about once a month or so.
Dick
Southern Comfort #1881
Tall rig, Wing Keel
Potomac River/Chesapeake Bay
You might want to read Mainesail's article, at www.pbase.com/mainecruising/self_discharge , m or on his new site, at https://marinehowto.com/winter-battery-storage-self-discharge-characteristics/ where, with his typical dilegence, he ran tests on a fully charged 12v lead battery he left in an unheated shed over a Maine winter. After 2 1/2 months, it lost essentially no charge and remained at its normal resting voltage. His conclusion is that In cold weather the self discharge rate of lead acid batteries slows dramatically to the point of nearly stopping, and that there is no advantage and many disadvantages to keeping it on a charger.
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
Great article Matt. Thanks. It convinced me to disconnect for the winter.
Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B
Now that you've decided, here's another consideration for others that may be contemplating "leaving it plugged in". OP's First Light has a Xantrex battery monitor, but what type of charger does he have? My 1999 C36 came with a really small (20 amp) charger that apparently has only a single phase - full charge. For that reason I have never just left it unattended, and am replacing it with a larger, more sophisticated ProMariner this winter. A basic charger can boil-off a battery because it keeps pumping juice as it does not detect that the battery is charged. Perhaps this is what happened to MrMac's "Southern Comfort", just a bit newer than mine.
John Parsons
"Water Music" 1999 Catalina 36 Mk II - Hull 1771
Tall Rig, Fin Keel
Bay City, MI, USA
John-
Off hand, I don't recall the charger model/brand, but it is a 30 amp unit and has a voltmeter on it's face. When full charge is achieved, the meter drops to 0, which is where its been since the boat was hauled/plugged in. The unit engages a cooling fan when the batteries call for a lot current. I leave the maintenance manuals on the boat, so can't readily pull the model information.
After reading the above article, I do have concern about a scenerio of somebody unplugging the boat, allowing parasitic loads to slowly drain the batteries when I'm not able to visit for an extended period. Hence, my conclusion that I should disconnect the batteries
Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B
[quote=Parsons]... For that reason ... am replacing it with a larger, more sophisticated ProMariner this winter.....[/quote]
Since I'm sure he won't do so, I'm going to put in a plug for purchasing things like chargers from Mainesail (a former C36 owner, also known as Rod Collins). He carries the Sterling Procharge Ultra charger, https://shop.marinehowto.com/products/sterling-pro-charger-ultra-battery-charger which I've found works very nicely as a replacement on our boat when the old charger started misbehaving. Mainesail's helpful input on the C36 forums over the years, and on his own how-to site, have no doubt saved me (and others) huge $$ over the years. He maintains that site as a service to the sailing community, and purchasing from him helps keep it going.
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
I agree 100% -- In addition to the Sterling Charger (which I got from him) - his buytl bedding tape is fantastic. As Matthew said MaineSale has contributed so much to help maintain our boats supporting this effort going forward makes sense.
Les
Les & Trish Troyer
Mahalo
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor.
Commodore