smoking batteries? can't be good

[KRS]

I have a dual battery setup through a perko? dual batt switch.<br /><br />Just started my boat tonight with the battery cover off (it is usually on) and I noticed a faint trail of smoke coming from one of the batt's NEG terminals. I felt it and whoa! it's hot!<br /><br />I felt that batt's POS terminal.. just fine. <br /><br />Felt 2nd batt's terminals and it's POS terminal was warm?!?!?!?!<br /><br />This occured just during cranking (replaced fuel pump, was cranking to get fuel pressurized). I switched to just one battery on the switch, NOTHING.. switched to only the other one and it started. Not sure if battery switch #1 and #2 coincides with the first and second batteries referred to above.<br /><br />Uhhhhh, how else can I say this but HELP !

 

[snapperbait]

Re: smoking batteries? can't be good

Resistance = heat.. <br /><br />Break out the little wire brush and clean clean clean all the connections.. <br /><br />If that don't help, you'll know it's time for a new switch and cables.. Corosion gets inside the cables, particulary at the ends, and breaks em' down..

 

[waterone1@aol.com]

Re: smoking batteries? can't be good

I agree with Snapper, sure sounds like corrosion and or loose terminals. Clean all and re-tighten.

 

[Bondo]

Re: smoking batteries? can't be good

Ayuh,....... Agreed,...... The terminal end that was "Hot", is Dirty.........

 

[AaronG]

Re: smoking batteries? can't be good

Look closely at the cables too. They can be all corroded inside and look fine on the outside. Its also worth looking at the connections at the starter and the connections at the battery switch.

 

[Jdeagro]

Re: smoking batteries? can't be good

Any extra resistance will cause the cables to heat up, but it sounds to me as if one battery is shorted (not just dead, but gone forever). The alternator is trying to charge the battery at high resistance as if it is discharged, when in fact it is shorted. Put a load tester on each battery.

 

[18rabbit]

Re: smoking batteries? can't be good

Ditto NautiJohn. Load test those critters, and in the process you can check the terminals and cables for corrosion as everyone else suggested. When bat cables become corroded you can often cut off a couple inches and everything past that is still good.

 

[olbuddyjack]

Re: smoking batteries? can't be good

nautiJohn,<br />Cant hurt to load check but normally a shorted battery will heat both cables not just one.

 

[AaronG]

Re: smoking batteries? can't be good

If you have a harbor frieght near you, they sell a decent load tester for $15. Its a useful thing to have around.

 

[zoom50]

Re: smoking batteries? can't be good

This happened to me when I made a mistake wiring my fish finder...one of my pos wires was touching the negative where insulation was worn off. Battery did not like that and started to smoke. Sounds simple, but I would double check you connections to make sure your pos is not touching your neg

 

[KRS]

Re: smoking batteries? can't be good

Very good ideas, I will take it apart and check for something amiss.<br /><br />If the cables are long enough, I think I'll take the ends off too....

 

[Jdeagro]

Re: smoking batteries? can't be good

olbuddyjack;<br /><br />You are correct. He has two battery system and I just felt it was a good idea to check with a tester. <br /><br />In any event, it sounds to me like he will end up needing two batteries. I make it a practice to change batteries evry two years even if they do not seem to be bad. Just a safety issue with me, as it takes a very long extension cable if your batteries go when out ot sea.