A Battery Question

Wandering Sagebrush · Posted: Sun Nov 16, 2008 9:53 pm Post subject: A Battery Question

Diana and I went to the beach house this weekend to see how things faired through the recent flooding. One local site had 11ish inches of rain. I had left my little aluminum boat there for fall chinook fishing, just sitting in the yard, with the transom plug pulled.

It looks like the wind blew a bunch of alder leaves into the boat, the alder leaves clogged the transom drain, and the boat was full of water up to the transom. The battery was about 8" under water. It seems to work fine now that I've drained the water out of the boat, but I am curious if there is a gotcha just around the corner. In all my years of working on boats and aircraft, a flooded battery is one calamity that I haven't seen before.

Any thoughts?

Steve

thataway · Posted: Sun Nov 16, 2008 10:46 pm Post subject:

Probably not a major problem if the battery is OK now. Rain water will be contaminated by the dirt in the boat, but the specific gravity of battery acid is higher than distilled (rain) water, and the water should be OK. Salt water is a different story--and there may be damage.

drjohn71a · Posted: Mon Nov 17, 2008 11:31 am Post subject:

Steve,

You don't mention how much of the wiring was underwater. One big, delayed set of problems is caused by water getting into an insulated wire and migrating along the length, causing corrosion and increased resistance at odd spots along the way.

I have purchased and rebuilt several sunken boats over the years and found the only way to predictably solve submersed wiring is to replace it. Some problems came up 3-5 years after the submersion. A good reason not to buy a flooded car also.

If only a short length at the transom end was submerged, maybe you could put a safety heater of sorts under a tarp in that area to try to dry out the ends of the wiring.

I don't think water hurts a battery much unless the acid is diluted too much.

John

Wandering Sagebrush · Posted: Mon Nov 17, 2008 2:06 pm Post subject: Thanks

Gents,

Thanks for the feedback. I had not considered the issue about water migrating up the cable, but as the only two connections are the engine and depth sounder, I don't have much to deal with. I think I will back the beast into the shop and warm things up.

Steve

Jack in Alaska · Posted: Sat Dec 20, 2008 12:55 am Post subject:

If the battery was full of water before the flood incident the rainwater would not get into the relatively sealed battery.

I have had a similar thing happen on a small skiff and the battery was fine and lasted for years after.