Stupid boat trick

[JeffM]

Don't deep-cycle batteries make just excellent weights on boat-building projects?  Like for holding down the seat extension you're putting on to make a comfortable cockpit berth?  Especially when you're drilling holes for the hinges?  Well, DON'T drill upward WHERE THE BATTERY IS.

Now that you've all finished laughing your ___ off, answer a question I have: how do you plug a 1/8" hole in the bottom of a battery casing?  (Right now, a piece of transparent packing tape appears to be keeping the rest of the cell from emptying into the bilge.)  And another: how do you replace several ounces of lost electrolyte?  (The battery was about fully-charged.)

[Peter HK]

Hey Jeff

I have no idea if the following suggestions will be helpful, or if you want to rely on them in this case as leaking battery acid is not something that is acceptable, but I understand that silicone sealants are pretty tolerant to acid and some will set underwater.

Also I've heard good reports on this stuff

http://www.whitworths.com.au/main_itemdetail.asp?item=64758&search123=epoxy&intAbsolutePage=2

with a friend telling me that when he was lifting out the diesel engine in his boat the lifting tackle failed and it fell a few feet and cracked the hull. This stuff completely fixed a major leak, setting underwater, allowing him to get the boat towed to a slip. Whether acid affects it or whether it bonds well to a plastic battery case I do not know.

Good Luck

By the way I'm still laughing ;D

Peter HK

[Bruce Kershaw]

Why did just I assume that a thread titled "Stupid boat trick", was started by Konrad?

[PAR]

Thickened epoxy will cure the battery hole thingy you've invented. You have to work quickly so the plates in the affected cell doesn't dry out.  Remove the electrolyte from the cell, rough up the plastic really well with 40 grit or less. clean the area with acetone or denatured alcohol, then apply thickened epoxy over the area, maybe with a small piece of fabric to keep it from cracking. Put the electrolyte back in, then top off with distilled water.

[JeffM]

Thanks, Peter and Paul.  I hope I haven't let the plates dry out--we'll see when everything is cured and I can put the electrolyte back.  If worse comes to worse, I'll have a rather expensive 50lb of ballast.  Fortunately this was my backup battery.

[Konrad]

I would simply buy a new battery and count it as tuition at the School of Hard Knocks.

x2

[JeffM]

Thought I'd let folks know how things came out.  I tried Peter's idea first: silicone sealant.  This hadn't cured at all after 24hrs (might acid have prevented this?), so I wiped it off as best I could and then wiped again with acetone.  Then I scuffed up the plastic and applied a big globe of epoxy thickened with silica and slapped on a leftover piece of xynole (to resist abrasion as I slide the battery around) and kneaded the whole and dropped the battery onto a piece of builders plastic to flatten things out.  I refilled the cell with fresh electrolyte the next day, worried by the two full days the plates had not been submerged in electrolyte.  The charger went green immediately when I hooked it up, which worried me still more.  Even so, the battery propelled my boat last weekend at 2.5kt for about 10 minutes during a calm--by no means an adequate test, but still reassuring!  I'll take an hour's fussing over giving up on a $90 battery any day!  Now if only my clothes didn't all look as though they'd been hit by buckshot...

[Ken_Potts]

I'm one of the people who would chuck the battery and buy a new one - In spite of that I'm really happy to read your posts about trying to fix the battery.  I don't think I've ever read anything anywhere about fixing a holed battery so as far as I'm concerned you're on the cutting edge.  I also admire your ability to post the whole thing.  We've all made mistakes like that but it takes some cahones to post an account so everyone can share in the laughter 

Keep us posted on the performance of your "new" battery.  Did the green light happen after adding the old electrolyte or did you add new stuff?  As far as I know the state of charge is dependent on the metal parts rather than the electrolyte but maybe some random electrical engineer will chime in (Tom?)...

[PAR]

I wouldn't have waited for the goo to cure, I would have used for plastic packaging tape to seal the hole, then a good bit of goo and some fabric for strength. As soon as it was done, wedge, brace, clamp the patch in place and put the battery blood back in. Hopefully you haven't damaged the cell too badly. How much oxidation can occur in a few days?

[Hirilonde]

I think I am with Ken on this one, in 2 regards.  I would have bought a new battery as well.  And I am certainly laughing, even though at your expense Jeff. 

It will be interesting to hear if battery repair is a feasible option. But even if the ability to hold a charge after losing the electrolyte for a day or so is not lost I am not so sure I would risk the leak and subsequent damage to my boat should the repair fail.  I'm a cheapskate too, but some risks aren't worth taking.

Now that you have exposed yourself Jeff, you must keep us updated with your results 

[paul_stewart]

Jeff,

Thanks for sharing your experience. When I eventually get around to putting a battery in our CS20, I'll be sure to think about how many holes I want in it. 

BTW,  it occurs to me that the mess-about School of Hard Knocks has two parts:   the out-of-classroom practical experience part,   and the in-the-classroom online Forum part.   It's a good curriculum design; we all learn a lot.

--Paul

[Frank Hagan]

I haven't checked these, but do those battery boxes they sell in the chandlery have a sealed bottom?  It might be worth getting one of those to set the battery in to prevent electrolyte from leaking into the boat if it does leak again.  Or a tupperware container or something.

I used a jig saw on the battery on my Potter; nice clean cut all along one side, at the top.  I could see it clearly when I finally had the cabinet door large enough to actually see into.  Didn't try to repair it due to the size, but it sure hurt to have to buy a new one.  I discovered Wal Mart had marine batteries at about half the price of West Marine.

[JeffM]

Okay, I could have kept my mouth shut and bought a new one.  But what would be the fun of that?

[Hirilonde]

Both of my group 27s on my Renegade are in boxes with tops and strapped into locations surrounded by raised cleats.  If I have any control over it, they are not going to:

1. ever move

2. ever cause or be part of a short

3. ever leak anywhere but into the box

I highly encourage boaters to do something similar whether they choose to drill holes in their batteries or not  ;D

(You know we can't leave this alone Jeff, and I like several others am most capable of such things as well)

[Frank Hagan]

At the very least, use those battery terminal covers that prevent something from shorting across the terminals, arcing, and burning your boat down to the bunks on the trailer!