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Author Topic:   Battery Leaking Acid
minitauk85 posted 08-13-2005 12:53 PM ET (US)   Profile for minitauk85   Send Email to minitauk85  
About one week ago I was cleaning out my 15 CC when I lifted the cover on my battery box. I saw a small amount of what appeared to be water approx 2 tablespoons. I took a cloth and blotted it up, smelled like eggs/sulphur. I put the towel aside on my back porch. A few days later while cleaning up my porch I grabbed the towel and it dissolved in my hands! Today I went to recheck the battery box and found some more (I am assuming this is sulphuric acid) approx 3-4 tablespoons. I took the boat out yesterday and it started and ran fine (forgot to check the battery then, ooops!). Question: this appears to be a leaking "Stowaway" brand battery, I am sure it's at least a year old, what do I do next? New Battery? If so what type do y'all recommend for a 15 foot center console?
jimh posted 08-13-2005 03:59 PM ET (US)     Profile for jimh  Send Email to jimh     
Most boats that size use a Group-24 battery. You can find marine starting batteries in a range of prices from about $45 (at Walmart) to several hundred for a more exotic type at a marine supply store.

Buying a battery from a nationwide retailer like Sears or Walmart may make sense if you travel with your boat and visit different parts of the country. Otherwise try a local store, maybe even your marine dealer if he has a nice battery at a decent price.

Due to their weight and hazardous content, I don't think you can get too many types of batteries mailed to you or sent via UPS.

minitauk85 posted 08-13-2005 09:47 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
I just checked the battery (still in the battery box) for signs of cracking etc... It appears that the acid (or water) is coming from both plastic covers where you add water when low. Is this normal? Do I need to worry about it exploding? Also is the battery box salvageable? Don't know much about batteries-k
Backlash posted 08-14-2005 10:32 AM ET (US)     Profile for Backlash  Send Email to Backlash     
The first thing I would do is pull the covers and check the water level in the battery. It sounds like the battery might have been over filled. If so, normal operation of the boat (pounding, etc.) would cause the battery to leak from the covers.

Your battery box should be plastic which is immune to deterioration by battery acid.

minitauk85 posted 08-15-2005 06:05 AM ET (US)     Profile for minitauk85  Send Email to minitauk85     
Will check for overfill this afternoon, thanks! If it is overfilled with water, then what? Turkey baster to remove extra water? Or can I simply pour some out of the battery? Will use the usual caution with acids (gloves, dilute with water, etc...). Thanks in advance - k
Robob2003 posted 08-15-2005 10:24 AM ET (US)     Profile for Robob2003  Send Email to Robob2003     
Go to any auto parts store and buy a hygrometer battery tester for about five bucks and use it to remove excess battery acid if that's the problem. Then you can use it to check on the battery condition in the future.

A turkey baster might dissolve in the sulfuric acid solution.

Bob on Tampa Bay

bsmotril posted 08-15-2005 10:27 AM ET (US)     Profile for bsmotril  Send Email to bsmotril     
If the regulator on the motor is faulty, and it is overcharging the battery, the electrolyte will boil over and come out of the battery cap vents. Check you voltage while underway at cruise. Bills
lloyd13 posted 08-15-2005 02:07 PM ET (US)     Profile for lloyd13  Send Email to lloyd13     
Sounds to me like the battery is boiling from too much charging. But it could be over-filled.
minitauk85 posted 08-15-2005 06:00 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
I took my "Stowaway" battery (Exide) to Autozone, they put it on a machine that "tests" batteries. Machine said the battery was "good" meaning it was doing what it is supposed to. I did notice a slight bulge on one end of the battery toward the top, also noticed water/acid getting more abundant in battery box, 4-5 tablespoons minimum. The manufacture date says Jan03. Water levels on all cells looked right. It seems to me the most likely problem is battery failure or impending battery failure. I think my most economical plan of action would be to buy a new battery for $40-$60 and see what happens. Buying testers would be cheap- volt meter for $10, hygrometer for $5, but it now seems most likely that the 2 1/2 year old battery is the problem and this might be the path of least economic resistance. Any thoughts about this plan? -k
Dick posted 08-15-2005 10:20 PM ET (US)     Profile for Dick  Send Email to Dick     
I agree with other posters, check your charging voltage. If it is to high you are going to boil out the electrloite.

The bulge in the battery suggests a bad battery but could be caused by overcharging.

If your charging voltage is good buy a new battery if it isn't don't waste your money untill the charging voltage problem is resolved.

When you buy a new battery, they are like everything else you get what you pay for. At the shops I have worked in for the past 15 years we have used nothing but Interstate Batteries and they work. Depending on the dealer, you are looking at around $80.00 for a good marine cranking battery.

Robob2003 posted 08-16-2005 09:43 AM ET (US)     Profile for Robob2003  Send Email to Robob2003     
If yo are looking for an Interstate brand I would look for an Interstate store rather than one of their dealers. I went directly to an Interstate store in St. Petersburg and bought one of their best #24 cranking batteries for about sixty bucks.

I saw the same battery at marine dealers for up to ninety dollars.

It pays to shop:-)

Bob on Tampa Bay

minitauk85 posted 08-16-2005 09:42 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
Will check voltage tomorrow afternoon-thunderstorms prevented me from doing it today! Not really sure what I'm doing with the volt meter (it's an old one and I'm not sure of the settings) but I'll try to figure it out! I appreciate all the help and will post results tomorrow, weather permitting! thanks again-k
Chuck Tribolet posted 08-17-2005 12:56 AM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
Check your voltage underwaw, but at faster than idle. At
least 2500-3000 RPM. When I had a similar problem, I made
a cigarette light plug for my volt meter so all it took
was a glance at the DVM.


minitauk85 posted 08-17-2005 06:21 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
Just put a volt tester on the polls to the battery- read between 15.5 to 15.7 consistantly for about one minute. Now what?
minitauk85 posted 08-18-2005 06:13 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
I also would love to go fishing in the morning (friday) and am not sure if I should run the motor if it is overcharging the battery. Can it do some harm to the motor as well as the battery? What if I use my 1-2-all-off switch to disconnect the motor after starting it, will this work?
minitauk85 posted 08-20-2005 04:43 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
Okay, no takers on what to do next, didn't go fishing yesterday...How about this: What should I expect to hear from my mechanic? regulator? magneto? what? I'm clueless-k
high sierra posted 08-20-2005 10:48 PM ET (US)     Profile for high sierra  Send Email to high sierra     
Minitauk, go fishing. Just turn on your dash lights, depthfinder and anything else to use up the excess voltage. A battery that is failing will cause the alternator to overcharge as well. high sierra
minitauk85 posted 08-21-2005 09:03 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
Just got back from the "super" Walmart. Bought an "Everstart" marine battery- not the huge yellow cool looking one, the $42.00 one. Hooked it up to my motor, attempted to turn the 1988 Johnson 70 hp over but it quickly died, not even 5 seconds of crank. put a volt meter on the battery and it registered less than 12, 11.something...hooked up my old ever swelling "stowaway" battery again and it fired right up...voltmeter also continued to climb to the high 14's before I got cold feet and shut her down. Is it normal to buy a battery from Walmart and it be undercharged? I believe the tag said April 05. Or, more likely, did I do something wrong? I'm pretty sure I matched or exceeded the specs according to my manual in regard to CCA,MCA, but could not find any reference to RC on the battery. Once again clueless-may be at my mechanics tomorrow-if he isn't too busy-k
high sierra posted 08-21-2005 10:21 PM ET (US)     Profile for high sierra  Send Email to high sierra     
Get the cool looking yellow one. Your new battery sat on the shelf for 4 months. Throw a charger on it first and try again. high sierra
bsmotril posted 08-22-2005 10:56 AM ET (US)     Profile for bsmotril  Send Email to bsmotril     
Never trust a new battery bought from anywhere to be ready to go. Always put a charger on it first, especially before heading out on the water. BillS
minitauk85 posted 08-22-2005 05:07 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
I took my old battery in to Interstate Battery in Suwanee, GA (north of Atlanta)local distributors for the company. They took the time to check out my Stowaway (Exide),checked everything on the battery including Hygrometer. They came back and said the battery is perfectly fine-top quality battery and nothing was wrong with it. Totally impressive to find honesty and integrity. They could have sold me a new Interstate and not have bothered to test the old one, they now have a future customer! I like to repeat stories of good customer service and honesty (keep in mind this is a warehouse that does some retail, not a parts and service type shop)! As for the Whaler, it's at the shop-thanks for everyones input, stay tuned, I may still have some questions!-k
minitauk85 posted 08-23-2005 08:09 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
Update: Mechanic says he thinks the problem is the rectifier-plans on replacing it. anyone know what is reasonable and customary for the part and labor? I'm looking for a ballpark figure here of course, any input would be greatly appreciated. Can someone explain in plain english what this part does and if this failure might affect my Humminbird and gauges? They have not worked since I bought the boat at the beginning of the summer, could this be a blown fuse due to the bad rectifier (hope I'm spelling it right!) or could it be worse, I fried my electrical components? Thanks in advance-k
high sierra posted 08-24-2005 11:39 PM ET (US)     Profile for high sierra  Send Email to high sierra     
Minitauk, the rectifier is a device that causes the current to flow in one direction. There are 3 diodes ( one way valves) that pass the current to the battery and elctrical system. They do not produce current. The voltage would be less if one of the diodes went bad. You have another problem. High sierra
jimh posted 08-26-2005 08:18 PM ET (US)     Profile for jimh  Send Email to jimh     
[Administrative post]
minitauk85 posted 08-26-2005 09:24 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
Took the boat out for a run today- ran well, beautiful day. Unfortunately the Humminbird only works when the motor is off, the battery reads 16 to 16.2 volts at the poles (still) while on the ear muffs in the driveway at idle. Mechanic pulled and replace a piece he called the rectifier, looks like a small metal cylinder with three wires, on a triangle shaped base. Don't know what is going on! -k
high sierra posted 08-27-2005 03:20 PM ET (US)     Profile for high sierra  Send Email to high sierra     
Minitauk, your motor is not regulating the power the alternator is producing. If you have a Zener diode that could be the problem. The zener diode acts as a pressure valve and bleeds off excess voltage thereby regulating the system. A lot of motors do not have such a system and just run flat out. Some have a true regulator on them. The depth finders shut off at 16 volts. High Sierra
minitauk85 posted 08-27-2005 04:02 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
High Sierra- I appreciate your input although I'm not sure what the next step is- I only hope my mechanic does! Any suggestions?-k
high sierra posted 08-27-2005 10:44 PM ET (US)     Profile for high sierra  Send Email to high sierra     
Minitauk, on one boat I had ,the motor cranked out to much power, ( volts) so I ran with my dashlights and marine radio all the time. Any kind of a load will usually handle it. I also had a small battery from Cabela's that I ran my depth finder off of. To install a regulating system is cost prohibitive. Just check your battery once a month and top it up if needed.high sierra
where2 posted 08-27-2005 11:58 PM ET (US)     Profile for where2  Send Email to where2     
Although beyond the scope of this particular website, if you picked up 3 diodes rated for 12A (from an electronics warehouse) and wired them in series, you could drop the charging voltage from 16v down to 13.9v which should be plenty for charging the battery.

The rectifier levels out the alternating current into direct current using diodes. The method I suggest with 3 diodes in series has the effect of dropping the voltage 0.7v per diode (2.1v total since wired in series).

I arbitrarily chose the 12A rating for the diodes since most engines on a 15' Whaler have a 6A max output from their engine charging system, and 12A would be a reasonable margin for safety given that it is a boat.

Alternatively, you could install some sort of voltage regulation device, but those are generally more complicated than my 3 diodes in series.

minitauk85 posted 09-01-2005 06:34 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
Got the boat back from the shop today. Mechanic did some wire repairs (secondary stuff to lights and depth finder) replaced the rectifier, and replaced the battery. So far so good- battery charging/operating at a little over 13 volts-can't wait to hit the lake tomorrow! thanks for all the help! -k
high sierra posted 09-15-2005 09:59 PM ET (US)     Profile for high sierra  Send Email to high sierra     
And what happened minitauk85 ?
minitauk85 posted 09-16-2005 08:34 AM ET (US)     Profile for minitauk85  Send Email to minitauk85     
To make a long story short I had some of the same problems happen on the next outing- reading high voltage at the battery while underway. Took the whaler to another mechanic as the running lights were blown and depth finder wasn't working (again)...he looked it over and it seemed to be charging at the correct voltage. Mechanic replaced some bulbs, reid some wires (not sure which ones) and checked the system, it checked out ok. I took it out this last weekend and put a voltmeter on the battery- same deal overcharging up around 15.4 volts continuously. Started smelling what smelled like electrical burning and headed for the hill. Needless to say it's going back to the shop this morning (haven't had my tow vehicle to take it back until today). Any suggestions?
high sierra posted 09-16-2005 10:45 PM ET (US)     Profile for high sierra  Send Email to high sierra     
Minitauk, go to Iboats boating forums. There are factory experts there on OMC's. I have to go there to get squared away every now and then. high sierra
Chuck Tribolet posted 09-16-2005 11:23 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
Wiring and lites and such can't make the voltage higher. The
problem is under the cowling somewhere.


minitauk85 posted 09-28-2005 05:52 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
Got an update on my motor charging problem today. Evidently these older series motors never had any sort of regulating system, they simply charged flat out. According to my mechanic (my new mechanic) the problem is not the stator or the rectifier, he says a kit is available that is designed to regulate the charging problem, hope he's right!I've been drydocked too long!-k
minitauk85 posted 10-02-2005 06:49 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     
Just got back from a very choppy, bumpy, windy run around Lake Lanier Island with my wife. Exhilarating! I took readings on the voltmeter on two different occasions and liked what I saw- the max charge was reading around 14.5 volts at the battery. It would register between 13.4 and 14.5 depending on whether the wife was using the power trim or not- needless to say I'm a happy camper! The part was not too terribly expensive, however the trial and error involved with two different mechanics still chaps my backside (and my wallet)!! I hope this thread saves someone with similar motor charging issues some cash! There is an after market part that helps regulate the voltage coming of the motor, unfortunately my depth finder appears to be fried as well as my tachometer (as a result of the last run on the lake). I am still hoping it may be a fuse somewhere- live and learn!-k
jimh posted 10-04-2005 12:40 AM ET (US)     Profile for jimh  Send Email to jimh     
Thanks for the follow-up report on the resolution of all the electrical problems in your boat. As your narrative illustrates, even though the electrical system on a small boat is extremely simple, it is often not well understood by owners or outboard motor mechanics.

The situation you encountered with your 1988 OMC 70-HP motor and its unregulated battery charging output is fairly common in motor of that vintage and horsepower. Because the current available from the motor's charging circuit was modest, it was often unregulated so as to not waste any of it. Regulation was left to be provided by the battery itself, which usually limited the maximum voltage to around 15-16 volts.

The tolerance of modern marine electronics to over-voltage varies with brands and models, but in general it is not a good idea to furnish them with more than about 14-volts maximum. Your purchase and installation of a regulator for your engine's charging circuit was a good idea and will be a good investment.

BQUICK posted 09-18-2006 10:14 AM ET (US)     Profile for BQUICK  Send Email to BQUICK     
Can you give us details on the aftermarket regulator?


minitauk85 posted 09-18-2006 08:21 PM ET (US)     Profile for minitauk85  Send Email to minitauk85     

BQUICK-the part was installed by my boat mechanic (the 2nd mechanic!) and he got it from Bombardier. The box the part came in also says Evinrude and Johnson on it. the description of the part simply says REG KIT V-4 V-6 part number 173640. It cost $123.00 plus installation for a total of around $200. The diagnostic to figure this problem out however cost me about $500 all told by going to guys that didn't know what they were doing. I don't know if your motor will require a different part or not but I would imagine they are pretty standard. I was amazed that more folks hadn't heard of this overcharging problem before, even some of the marine mechanics at the 2nd marine repair place I went hadn't heard of this. Good luck - k
MyOutrage posted 09-28-2006 05:41 PM ET (US)     Profile for MyOutrage  Send Email to MyOutrage     
Where2... how does your "3 diodes strung together" solution stack up to the $123 price tag for a Johnson solution?
Chuck Tribolet posted 09-28-2006 08:04 PM ET (US)     Profile for Chuck Tribolet  Send Email to Chuck Tribolet     
Where2's solution just drops the voltage by a fixed amount.
.7V is a typical drop across a diode. So if the alternator
is putting out 16V, you get 13.9V with three diodes. But
if the alternator is only putting out 13.5V, you get 11.4V.

The Johnson solution is a real voltage regulator, probably
even temperature compensated, hence a good deal more


MyOutrage posted 09-29-2006 12:28 PM ET (US)     Profile for MyOutrage  Send Email to MyOutrage     
Ah... then the Johnson solution makes alot more sense and really isn't that expensive.

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