Cause of 16 volts DC

[Matthew A.]

After leaving my deepcell/start battery on the charger to long, the volts went from 13.8 to 16 at mid/upper rpms. I figured the battery was at fault so replaced it with same make model. Volts remained reading at or near 16. Figured the rectifier maybe the cause so replaced it. Volts continue to remain at or near 16. I notice that the voltage of the replacement battery after starting the engine reads about 12.0 volts and takes a few minutes to get about 13 volts. Something the old battery didn't take but just a few seconds to reach 13+. The voltage also seems to drop faster then the old battery and also never reads above 12.7 volts with engine off with fish finder on. I took the replacement battery back to PepBoys where I purchased it. However, when they tested it they claim the battery to be fine and refuse to replace it. Is the higher then norm voltage a battery issue or possibly a stator issue?

 

[Dunaruna]

Re: Cause of 16 volts DC

Hi Matthew, welcome to iboats!!<br /><br />The boys here will help you fix your problem, they are very very smart guys, but they need to know what motor you have first. Make, year, HP etc etc.<br /><br />Aldo

 

[ljshein]

Re: Cause of 16 volts DC

Matthew,<br /><br />I had a similar issue with my force 125. Votlage was all over the place. Turned out there was a wire behind the coil pack that after years of vibration had rubbed the insulation off the wire and was grounding against the block. The wire was ok so I used some shrink wrap to insulate the wire and problem was resolved.<br /><br />Good luck!<br />Jeff

 

[andy6374]

Re: Cause of 16 volts DC

Like Dunruna said, the more info the better we can help.<br /><br />Typically though overcharging is a symptom of some easily overlooked things:<br />1.) All connections between battery, rectifier, etc. are tight and free of corrosion and check for rubbed insulation of those wires.<br />2.) Toss the wing nuts on the batteries and lock the cables down with stainless steel nuts and star washers.<br /><br />Also what battery are use using? Brand and Model(ie. deep cycle, maintenance free, starting..)

 

[Matthew A.]

Re: Cause of 16 volts DC

First off, thank you everyone for responding to my post. It is greatly appreciated.<br />Oops! I guess it would tend to help my cause if I supplied the make of the motor. The motor is a Force 85 hp. B model. I am not certain of the year. It is either an 88 or an 89. Either way, they both take the same parts accept for water pump and exhaust plate gasket. Anyhow, the battery I am currently using was purchased at PepBoys autoparts. It goes by the name Energizer. It is also said to be a marine deepcycle/starting battery with a reserve cap of 180 min. I know not to use maintenance free batteries as they are susceptable to damage by overcharging above 15.0 volts. I have completely gone thru every inch of wiring under the dash and all wiring connections at the motor. Due to the voltage readings of the replacement battery going below 12.7 volts after running only my fishfinder for only 10 minutes or so and from the information everyone has so kindly given me, the battery is beginning to be more and more suspect. I am beginning to think it maybe worth a second attempt to return the battery back to PepBoys and nicely insist they replace it since it comes with a 1 year free replacement guarantee. I am wondering, the only electronics I have running with the motor off is my fish finder aka Matrix 25, VHF radio to monitor CH 16, LED anchor light [night time only] and every 10 minutes or so I run the bait pump for a minute or two. I rarely sit for more then two hours with the motor off. Considering the max output of my charging system is only 7 amps, would I be better off using a starting battery or ?

 

[BOBPELL]

Re: Cause of 16 volts DC

What are you measuring the voltage with? A good quality VOM or are you relying on the boats volt gauge? I'd borrow a good digital multimeter and double check your readings!

 

[Matthew A.]

Re: Cause of 16 volts DC

The readings I have obtained while using both my fishfinder and my voltmeter.

 

[Richym01]

Re: Cause of 16 volts DC

Hi Matthew<br /><br />I have a Force 90hp 19991. When mt boat is running at WOT the volt meter shows about 15.6 and when you slow down to tick over it show about 12.8v. I find this normal and have never had a problem with it.

 

[horsefly38425]

Re: Cause of 16 volts DC

your gauge/meter are showing volts going in when running and that sounds high to me . i burnt a batt up running 16+ i changed batt and had no trouble /don't know what happend /still working on it

 

[andy6374]

Re: Cause of 16 volts DC

You want between 13-15 volts. Low 15's are OKAY as well.

 

[Matthew A.]

Re: Cause of 16 volts DC

Thank you for replying everyone.<br /><br />quote from "horsefly38425"...<br /><br />"your gauge/meter are showing volts going in when running and that sounds high to me . i burnt a batt up running 16+ i changed batt and had no trouble /don't know what happend /still working on it" <br /><br />Hmmm, looks like you and I are in the same boat then...lol

 

[Downrigger]

Re: Cause of 16 volts DC

My 1992 Force 150 will charge at about 14 volts until the battery seems to reach full charge or when I run for a period of time at higher RPM. Then it creeps up to just under 16V and stays there at higher RPM. I've checked the 12V system when running at higher RPM with both my portable GPS plugged in and with a good multimeter. They both read about 15.8V<br /><br />After running for several hours I've even checked the batteries to see if they are getting hot and they are not and the water is not decreasing in the cells. There doesn't seem to be any negative consequences with this. Ran the boat all season like this last year.<br /><br />I read somewhere in the owner's or shop manual that when the batteries get to full charge the charging system discharges to ground to prevent overcharging the batteries. That may take the place of a voltage reg. When it sees under 12V at the batteries it begins charging them again.<br /><br />I know that if I have to crank the engine a few times to get it to start in cold weather the on-board meter stays longer in the 13-14 V area and sooner or later slowly creeps back to just less than 16V once the batteries re-charge.<br /><br />It only started doing this when I replaced the batteries last year. I had one bad battery that would not hold a charge and the meter stayed at 13-15V all the time. Coincidence, I don't think so. Matybe it's supposed to work this way?<br /><br />Downrigger

 

[jaba]

Re: Cause of 16 volts DC

Hey Matthew,<br /><br />Had that high voltage problem with my 120hp 1992 last summer. Checked all the connections for corrosion and loosenes, nothing changed. In my case the thing causing high voltage was the battery. Dunno what was wrong with the battery (normal car battery), but when I changed it to free time battery the problem was gone. Still going easily near 16 volts, but all the equipment are working. Radio and fish finder went dead when voltage goes over 17 volts.<br /><br />Hope you find the solution, let us know.<br /><br />-Jaba-

 

[jaba]

Re: Cause of 16 volts DC

You might wanna look at this thread:<br /><br /> http://forums.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=33;t=006361#000006 <br /><br />-Jaba-