Hot Battery

[j-bass]

Just trying to figure out why this is happening.  Time before last: went fishing, and when I got done, I was taking the power cables off of the batterey and the wing nuts were hot to the touch.  This last time: same thing, but when I got done and touched that wingnut, it burnt the crap out of me.  Is my batterey fried? (its not that old, 6mo tops).

-J

[Cajun1977]

maybe a bad cell  with it only 6 months old  dont take any chances with it  the warranty should still be good id exchange it

[Way2slow]

Nothing wrong with the battery. This is caused by bad connections. You need to clean the cable ends so they are bright and the post and lead around the post until it's bright. Throw the wing nuts away and get you some hex nuts and tightened them with a wrench, if you insist on wing nuts, use pliers to tightenen them, make sure you don't have washers under the cable ends between the ends and battery. Brass nuts and lock washers or silver plated nuts and lock washers work best, if you can find them If you still get heat after doing this, most likely the cable ends have bad crimps and are not making a good connection with the wire inside. You will need to cut them off and get new terminals, crimp and solder them on. You may have to cut several inches of the cable off if it's discolored from the heat so you can get back to clean bright copper. As I've posted before, with the amount of current these motors draw, it only takes a small amount of resistance to generate large amount of heat.

Just to give you an example of how easy it is to get one hot.  1 ohm of resistance and 35 amps of current would create enough heat that it would be like trying to hold a 35 watt holigen lamp.

[IneedAnewScreenName9886691]

I have a boat that's battery was doing the same thing.  THANK YOU WAY 2 SLOW!!!!!!!!!  

SOLID ANSWER!

[RobDar]

way2slow hits it on the head again...

you can tighten the wingies with a pair of pliers though...the wrench and nut is not necessary. I seem to remember, though do not quote me on this, that battery manufactuers recommend 40 foot lbs of torque? Which you can easily get with a pair of needle nose. I may be off on that, been a long time since I did any serious DC/battery cell wiring.

Clean everything with a wire brush till it is all shiny and clean...

Make sure everything...crimps on connectors on cables etc...are tight...

Tighten everything down good and snug...

you can also put a "grease" called Pentrox on the connection...it is an  electrically conductive anti oxident but also helps disapate heat.

If you are still getting heat...THEN I would check the batteries.

[MyKeyBe]

Along the same lines a bad ground will do the same thing as will any bad connections. Any acid/gunk on top of the battery will slowly allow the battery to short itself out and create heat. Also too small a cable will create heat.

It all comes down to resistance. You want the power to flow as freely as possible. Bad/loose connections, corrosion, too small a wire, air gaps, etc. all create resistance and heat.

[RobDar]

It all comes down to resistance. You want the power to flow as freely as possible. Bad/loose connections, corrosion, too small a wire, air gaps, etc. all create resistance and heat.

it all comes down to resistance...and resistance causes heat...and heat causes resistance...and resistance causes heat...it is a self replicating problem.

[fish-fighting-illini]

All above mentioned points are valid. It can be a little complicated but you shouldn't have to have a death grip on the connections to avoid the heat. The only time mine has heated up was when a connection came loose. Can be any # of problems. I would maybe rate the odds in this order:

1) connections at battery

2) wiring problem elsewhere other than at battery IE short or ground problem or bad splices somewhere

3) trolling motor drawing more amps than it should

4) bad battery (not likely with being new but possible)

If you know how to do it as a test you might try to isolate the tm from the rest of the functions( if possible) take an extra battery and run just the TM on that battery. If the orig battery it still gets hot then you have narrowed it down. If the TM battery gets hot then you lean that direction.

If you get it narrowed I can give you some additional ideas.

just trying to lend a hand

[Way2slow]

Folks,

Heat is generated at the point of resistance.  If the wing nuts are getting hot enough to draw a blister, that's the area of resistance.  Either they're not making good connection or the cable end has a bad crimp, it's that plain and simple.   Like I said, for those who think wing nuts finger tight are just fine and use them, that's great, it's your equipment, just keep burn cream handy for when you grab one just after using the tm, one of these times it's gonna get you.  If the whole cable was getting hot from end to end, then the cable is too small for the load.   If there was a bad splice or connection somewhere up the cable, then that's where it would be getting hot.  If water was boiling out of one cell of the battery, then you could figure the battery has a bad cell.   Wet, dirty batteries getting hot is rare since doing away with the lead tie straps, and even then it's on the surface of the battery and you can smell them.   If the whole battery was getting hot, then you could figure a possible bad battery or way too much amp draw on the battery.   Yes, copper conducts heat, but for enough heat to conduct down the cable to burn his finger at the wing nut, caused by a bad conneciton up the cable, he would have to have a major melt-down with smoke and flames going up there.

Don't go chasing around you elbow to get to your appitite.