No Juice

[Cuddy]

Any ideas on why a battery would drain after sitting for 2-3 wks with nothing left on? <br /><br />I've got a 2001 135hp Mercruiser I/O attached to a 19' Bayliner Cuddy Cabin.<br /><br />Never had a problem in the summer when the boat went out every few days but now when we have to choose our days carefully in North Texas the boat sits a while and this has happened twice. I know I could unhook the battery but it shouldn't do this anyway should it?

 

[petryshyn]

Re: No Juice

You may have a tired battery(sulphated), weak charging system or something called parasitic drain. Take the negative battery cable off and install an ammeter between the post and the cable. If you get a reading, you have a parasitic drain that will draw your battery down over time. If you have alot of electrical accessories, some drain can be normal. Typically 50 milliamps is a maximum allowed and will flatten an averaged sized battery in 2 - 3 months. If your ammeter shows more than 50 milliamps, keep disconnecting accessories and connectors until the draw goes away, then you'll know where the culpert lies. If your ammeter shows less than 50ma, I would have the battery tested for sulphation and also check the charging system to see if it actually is bringing it up to FULL charge. A weak charging system can lead to premature battery failure, which might be what you're experiencing now. Be sure you have atleast 13.8 volts while running.<br />

Happy Boating!

 

[DP]

Re: No Juice

Do you have a stereo radio on the boat? We found that they would drain the battery even when turned off. Install a battery on/off switch and you can prevent any drain.

 

[suzukidave]

Re: No Juice

I agree with Schematic about the likely causes but I would just install a battery on/off switch unless you have a big drain. It's a good safety feature anyway and it's there for the next time you leave the sounder on (there will be a next time). If you get into the habit of turning off the battery every time you leave the boat, there won't be a problem.

 

[petryshyn]

Re: No Juice

Good advice from Suzukidave. A master switch on any battery-powered system can be your best friend. It will eliminate parasitic drain (unfortunetaly you may lose memory presets) makes the boat harder to steal and sure helps in the event of an electrical fire. One thing I forgot to mention is "case leakage" (battery drain caused by a dirty wet battery top) Take your voltmeter and connect the black probe to the negative post. Take the red lead and drag it all along the top of the battery. (especially wet and dirty areas) If you get a reading while doing this, you have case leakage. In severe cases, this will also kill the battery over time. Easy to rectify...wash off the top of the battery with a mixture of water and baking soda. Then retest.<br />

Happy boating!!

 

[Cuddy]

Re: No Juice

Thanks, I do have a CD player and that is all I thought it could be so it probably is. I think I'll go with the battery on/off switch. Thanks again.

 

[Rex]

Re: No Juice

Bad cell in the battery.<br />Rex

 

[Dunk]

Re: No Juice

Does the boat have a Mercathode electrolisis system on it. They draw some juice over time. Being a new boat you are probably still living with the joke of a battery that came with it. If it isn't at least a 27 series battery your just kidding yourself. The only thing on a stero I can think of that would pull power is if it had a clock in it. A digital clock doesn't pull more juice than what a battery would loose just sitting. If this is what is killing it I agree with the guy whos said the battery has a bad cell.<br /><br /> Remember when you install a main battery switch, and all boats should have them, is the only thing you should have hooked to the battery is a fused wire to your auto bilge pump switch. This way when you turn the switch to off the bilge pump is still hot. This is a big point if the boat sits in the water. Everything else including the main power wire from the boats fuse/curcuit breaker panel should be connected to the "Com"(feeder) terminal on the battery switch.<br /><br /> Battery Switches,,,, try to buy a Guest or Cole Hersee switch that rotates all the way around instead of the ones with a 40-50 degree throw. They are simpler and it makes it harder to go past "off" on the switch while the engine it running. Buy one that will handle two batteries. Which brings up a good point. If you are in there installing a switch you might just as well install another battery. This will end any problems you are having. Here's some pretty simple wiring lay outs for battery switches.<br /> http://www.perko.com/diagram2.html

 

[Rex]

Re: No Juice

Have you tried at least another battery<br />to see if it was a bad cell.<br />Rex