Hello,
Hopefully these 3 pictures will upload. I just purchased Summer Wind last month, and have been working on some upgrades. One of which will be adding a battery monitor (Victron BMV-712) . To say I "uncovered" a potential issue in my battery compartment, might be an understatement. The first photo shows how my house bank of (2) 4D AGM's under the starboard rear seat is secured down. Two lengths of wooden 2x4's painted with white primer. Not sure if this was original to the boat, but I suspect it was a modification by a PO. Upon removing them and turning them over (see pics 2&3), I found they had burn marks. The closeup in pic 3 shows it significantly charred black as coal where it covered over battery #2.
Okay I can handle a lot of things, but this stopped me in my tracks. Has anyone ever seen this before? Can batteries get so overheated that they can cause this and yet not show other signs of damage (melted wires, etc.)? My current bank is only 2 years old and tests well within limits down to 50% discharge and back up to full charge - no overheating. There is absolutely no visible damage from any warping or melting of the battery's plastic top or vent caps. There is nothing visibly notable on the underside of the seat support plank. Also, the wood doesn't smell smokey, as would a recent burn. In fact, it almost looks as if there was an attempt to paint over the burnt areas, since the worst of the two boards is the only one with paint on the bottom. (Could someone have pulled these out of an old scrap pile to save money?). Given the boat's age, it's probably on it's 4th set of bats, so it could have been a previous issue. The most recent owner had the boat since 2012 when he replaced batteries, and then replaced again in 2019. He kept meticulous logs and did a fair amount of cruising, but there is no mention of any electrical issues. I reached out to him today to see if he can recall anything.
Obviously, I'm not putting the 2x4's back in and would love some advice on a better way to lock the bats down. Also need to add a negative bus bar and the shunt for the BMV, but not sure where to fit it all in there neatly.
Thanks all!
Chris
"Summer Wind"
2000 Catalina 36 MKII, #1885, Standard Rig, Wing Keel
Home Port: Lighthouse Point, FL
"I fly, I sail, I throw caution to the wind.
Drift like a stratus cloud above the Caribbean..."
--Jimmy Buffett
Chris;
First. It's not too unusual to see the batteries tied down with pieces of 2X4 or 2x2. When owners modified the original battery complement and needed to secure the batteries, many configurations were used. So long as the batteries are secure and can't shift, I think you'll be ok with new pieces of wood.
Second; I'm willing to bet that since you can't smell the wood burn, that the wood many have been exposed to burns from battery acid.
Of course, it is possible that a battery can heat up during the charging process and many battery chargers have a heat sensor for this very purpose. You also might find that the plywood underneath the batteries will need replacing as well. I think once you get you new batteries in place, you'll be fine.
Bill
Bill Dolan 1990 Catalina C-36 MKI - Hull #1041 'Williwaw'
Std. Rig, Walk Through, Wing Keel
M35, Oberdorfer Conversion,
Home Waters; Charlotte Harbor & The Gulf Islands of Florida
'You are never out of work if you own a boat'
My 1999 C36 batteries are also secured with 2 2X4 and painted. These are factors installed. My batteries are placed in a shallow fiberglass tub, no plywood below.
The shunt is in the battery compartment.
Haro.
Sail La Vie 1999 Catalina 36 MKII, M35B-17031, Coyote Point, San Mateo, CA
About Sail La Vie
My 2003 C36 has its batteries secured with 2 2x4 and painted. The condition may be caused by off gassing from the batteries. On my boat the battery charger was replaced shortly before I bought the boat and the yard’s technician set the charger up incorrectly and the batteries were being over charged. The charger was set for another type of battery and was charging at 16.9 volts causing the batteries to start bubbling inside while being charged. I was lucky that I heard it and look into what was causing that to happen.
Bob Wilson
S/V Morning Breeze
2003 Catalina 36, Hull 2122
York River Yacht Club
Williamsburg, VA
I have exactly the same configuration as yours so that must be pretty standard in others. As for the discoloration it looks more like wood decay than burn marks. There would have to be excessive moisture in that area for a long period to cause that. I would think that if the batteries were over filled that would dry out long before decay could set in. Good idea to check with previous owner
Thomas Tydeman
2002 Catalina 36 Mk ll
Hull 2074 Tall/Fin
Old Saybrook, Ct
One thing I strongly recommend is ditch those wing nuts. Get yourself some good stainless nuts and crank them down nice and tight. I don't see any fuses on those smaller red wires.
2003 Catalina 36
Gents.
Thanks for the replies and sorry I haven't replied until now. I've been busy with this and other projects. From most of the feedback I've gotten here and some other sources, the battery acid fumes built up over time seems to be the main culprit here. The previous owner (who I know), was shocked when I showed him the photos. He said the bats were professionally replaced in 2019 and the previous set were constantly overheating and not holding a charge (after 6 years - no surprise!). The installer either didn't notice the wood or just didn't mention it. Either way, the acid fumes cause the wood to darken and dry out. Over time, humidity creeps back in, especially down in FL in the summer), then fumes dry it out again and the process repeats until the wood looks rotted and burnt out.
So as a remedy of sorts, I replaced the wood with 3/4" thick Starboard - very strong, which also provided me with some added clearance to install a negative bus bar and a new Victron 712 battery monitor shunt (previous wood thickness wouldn't have worked as the bus bar would have been sticking up too high for the seat plank). See pic below. BTW, the new battery monitor works perfectly and is soooo much better at determining the health and whats going on in the batteries than the original analog voltmeter.
Good point about the fuses on the smaller red wires. One has a fuse along side the battery (out of sight in pic), and the new BMV shunt wire running across the top has one just under the starboard brace. I'll have to check the others.
I did not check supports below the compartment. By myself at 57, and not without some lower back issues, there's no way I'm pulling 2 of those batteries out and back in. I figure I've got a year - maybe two left on these bats and they can check it then, but I'll keep a close eye on it in the meantime.
Thanks for all the feedback and advise. Hopefully if some future new owner sees that problem and does a search, they'll come accross this conversation and relax a little!
For my next trick - replace the rusty and leaking old water heater...Fun!!
Cheers and Happy holidays!
Chris
"Summer Wind"
2000 Catalina 36 MKII, #1885, Standard Rig, Wing Keel
Home Port: Lighthouse Point, FL
"I fly, I sail, I throw caution to the wind.
Drift like a stratus cloud above the Caribbean..."
--Jimmy Buffett
Oh and the wing nuts - going to replace those too - thanks!
Chris
"Summer Wind"
2000 Catalina 36 MKII, #1885, Standard Rig, Wing Keel
Home Port: Lighthouse Point, FL
"I fly, I sail, I throw caution to the wind.
Drift like a stratus cloud above the Caribbean..."
--Jimmy Buffett
Chris; What size batteries are those ?
Bill
Bill Dolan 1990 Catalina C-36 MKI - Hull #1041 'Williwaw'
Std. Rig, Walk Through, Wing Keel
M35, Oberdorfer Conversion,
Home Waters; Charlotte Harbor & The Gulf Islands of Florida
'You are never out of work if you own a boat'
Hi Bill,
They are 4D AGM's rated at 198 a/h's each and 1110 CCA. (West Marine). 131lbs each - ouch!
When these are done, I'll be adding a dedicated start battery, and possibly changing the house bank config to (4) 6V bats instead of the (2) 12's. Not sure yet.
Chris
"Summer Wind"
2000 Catalina 36 MKII, #1885, Standard Rig, Wing Keel
Home Port: Lighthouse Point, FL
"I fly, I sail, I throw caution to the wind.
Drift like a stratus cloud above the Caribbean..."
--Jimmy Buffett
We have a1999 C36, one yr old to us. We also have the 2 D AGM batteries with 2 2x4 studs to secure them in place under the starboard sette next to the nav station. We added 4 6v golf cart AGM batteries under the nav station (we removed permanently the swinging nav chair). What we found is the 70lb 6v batteries (4x70=280lbs) caused our boat to list to the starboard, we believe from this extra 280lb weight caused the listing. we are now considering moving the 4 6v agm batteries from starboard to a new location on top of the bildge.
Yes that's a lot of additional weight if, as I assume, you still have the other 2 AGM's under the game table seat. You could try some ballast on the port side, but at some point you've got to consider how much weight you actually want on the boat. Not sure where "on top of the bilge" you could make that work unless you've got some room under the seat directly behind the galley sink (which is more or less closer to the centerline).
Chris
"Summer Wind"
2000 Catalina 36 MKII, #1885, Standard Rig, Wing Keel
Home Port: Lighthouse Point, FL
"I fly, I sail, I throw caution to the wind.
Drift like a stratus cloud above the Caribbean..."
--Jimmy Buffett