Hello all, My big old 4D 210 ah AGM house bank batteries on my 1994 C36 have finally died. I was about to run out and buy new ones and get a second mortgage to pay for them when I started reading the many good and very thorough articles herein on the recommendation of upgrading to 6 volt golf cart batteries. After reading all the great stuff on the subject I'm convinced that is way I want to go. One aspect I didn't see discussed is the question of hydrogen gas emissions into a poorly ventilated compartment. The Technical advisor at my local battery store was adamant that this would be a big safety issue with wet cell batteries. Although, I'm pretty sure that the boat was delivered originally with wet cells installed in the same compartment. Is this not a reason for concern?
thanks,
Sam
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida
We haven't managed to blow our boat up with flooded batteries, but I do note that there are 3 1" holes near the top of the forward wall of the battery compartment (ie., facing the well below the small table) that appear to have been cut by a prior owner.
We use GC1 6 volts on ours, and have found them quite satisfactory. Of course one does need to check the water levels regularly, it will ruin them quickly if the levels drop enough to expose the plates (DAMHIK!).
By the way, not all GC1s are alike; for example, Interstate Battery dealers (where we got our last set) carry a variety, including a 242 amp hour (20 hours) rating GC1( that's what we installed) costing only a little more than their 216 AH. (If I recall, its actually made by US Battery, model USB-125, http://usbattery.com/wp-content/uploads/2015/01/usb_125_data_sheet_2015_...(link is external))
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 converted to GC batteries long ago and never regretted it. The only times you will have water gas off and have hydrogen is if your batteries are bad and constantly boiling off water or if the charger fails. I had a bad cell in the original 4D battery and smelled rotten eggs as the water was gassing off. The compartment is not air tight and the smell was very apparent.
Gene Foraker
Sandusky Yacht Club
Sandusky, OH
1999 C36 #1786
Gypsy Wagon
Thanks for the replies Mathew and Gene. Apparently no one is particularly worried about this issue except the guy at my local battery store. Although he's been around longer than me and seems to know a lot. so I think I'll proceed to convert to the four 6v golf cart wet cells. I may consider cutting additional holes in the box. I'm assuming our boats were originally delivered with wet cells installed in these same boxes??
So Catalina wasn't worried about it either?
I've not heard of any incident involving the ignition of hydrogen aboard any boat. Of course that doesn't mean its not happened.
Thanks
Sam
Capt. Sam Murphy
1994 Catalina 36, Hull 1327
Shoal draft, two cabin model.
Panama City, Florida
The ABYC requirements for battery box ventilation are no different for AGM, GEL or Flooded batteries. Anyone suggesting that AGM or GEL batteries can't vent is giving very, very poor advice.. Equalize some Lifeline AGM's and then tell me they don't off-gas... (grin)...... ALL lead acid batteries need adequate ventilation. I prefer a low and high vent to create a natural chimney effect and self-circulation venting these are super easy to cut in if not already there. That said I don't know of a single fire or explosion caused by a lead acid battery due to venting issues. Probably is one, but far lower on the fire risk scale than bad electrical installations... Usually it is the lack of over-current protection that starts fires...... (wink)
-Maine Sail
https://www.marinehowto.com/(link is external)
Capt. Sam;
Just one additional thought. Batteries such as these do give off gas and one should be careful as to what is mounted in close proximity to the battery. We saw a high frequency radio (SSB) that was virtually destroyed because it was mounted very close to a battery that was venting. Completely corroded the radio.
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'