Starting Battery

[dougr1969]

All,

I have a quick question about my starting battery. I have gone through 3 of them this summer alone. These were all $60.00 marine starting batteries from Wally World but is that normal? Am I suppose to charge my starting battery? I thought the alternator in my engine kept the starting battery charged. I have a 1997 16ft Lung Angler SS with a '97 Mercury. Can someone please give me some suggestions on why this might be happening. I have looked at what I believe to be the obvious (leaving the radio on/ lowrance 330c) Any help would be much appreciated. Thanks in advance!!

[deadminnowcatcher]

I have the same motor and had the same problem once. I hope you kept the batteries as i bet they are just fine. There is a part on the motor that controls the charging system and i bet that is what is bad. I cant remember the name of it-- maybe rectifier??? anyways it is an inexpensive fix. I almost guaranteee you that is what it is. sometimes they get blown if you charge the battery without disconnecting from da motor. good luck and dont throw the batteries

[Tom7227]

get a battery charger and hook it up and they all probably are OK. You should be able to get a decent charger for $50 or so, much less than what it will cost to repair the electrical problems with your motor.

[dougr1969]

Thank you both for your replies.

Deadminnowcather- I will place a call and ask around about the "rectifier". Thanks again.

[solbes]

This happened to me once. I reversed the polarity of the starting battery and that almost always fries the voltage rectifier. You can tell this has happened by watching your battery voltage during running (should be 13-14V once underway with a good battery). I use my depth finder display to tell me voltage. The other way you can tell is if your tachometer is not working. Apparently the two are tied together.

As for the fix, a new rectifier for my '84 Evinrude 90 was under $40. Replaced it myself and I'm no boat mechanic by any means. You definitely want to fix it, rather than continually manually charging your battery.

[Sandmannd]

I algree with solbes, get if fixed or fix it yourself. Nothing worse that hauling batteries in and out of the boat. Not to mention getting stuck on the lake with no battery.

[marine_man]

I would measure the voltage, using a mulitimeter or the display on your locator before you start the motor, then start the motor and run the throttle past half - does the voltage rise? If it doesn't then it sounds like your rectifier is very likely out, as could be your stator - you'll want to check that out before replacing the rectifier. If the stator is bad it will take the rectifier with it.

If your voltage does rise you've eliminated the expensive repair.

Do you have the power for your 330 on a switched circuit? If not the gps reciever will continue to draw power, even though the locator is off. Overtime this will drain the battery. How long does it take to drain the battery?

Oh, and buy a 12V charger and charge those 2 other batteries up - there's nothing wrong with them, they're just low on charge.

marine_man

[NCLaker]

Don't know much about the mechanics on boats/motors. But I installed a new radio replacing an old one on my pontoon. After putting the new one in I noticed that my battery would go dead sitting on the lift.

My old radio had only one power lead to it and my new one has two (one for ignition, other to the battery). I guessed and put both new wires to the battery figuring that would be fine as long as I powered my radio off ... wrong. Went back and rewired by piggybacked my radio ignition lead to a panel switch also used by my fish locator ... haven't had a problem since.

Interesting to hear Solbes' comment on effects on the tachometer when the rectifier is bad. My tach for the most part has not been working, except every once in a while it kicks in and starts working until I shut the engine off again (also happens with the speedometer). Does this sound like symtoms of a bad rectifier? Someone mentioned that it may have to do with a bad/loose groud somewhere or bad tach. I can start a new thread if necesary - but if anyone has suggestion on the problem, or how to find a bad ground please let me know. Finding the ground problem is scary since there is a ton of wiring under the console with no wiring diagram to guide me.

[marine_man]

A radio will also pull the battery down, but that usually takes longer than the GPS alone - it pulls power to keep the clock and your presets stored, so good addition.

With respect to your tach working sometimes - I'd say it sounds more like a loose connection problem than a rectifier - they almost always work or don't work, nothing in between.

marine_man

[NCLaker]

Thanks for the quick feedback MM. There are a ton of wires - any suggestions on where to start or focus the efforts on? Is there any wires in the motor I should be checking or just under the console?

I am hoping it is not a cracked wire, intermittent short - I am guessing that would make it trickier to pin point.

Sorry again for taking this off topic. I will create a separate topic if I need to post more on this problem. Thanks!

[NCLaker]

... sometimes they get blown if you charge the battery without disconnecting from da motor. good luck and dont throw the batteries

Interesting - I had always assumed you could keep your starter battery hooked up to the motor if you ever had to to put a charger on it. Does this problem only occur if your charger does not automatically go into trickle charge mode? Also does the risk of blowing the rectifier with a battery charger only apply to an outboard motor, or does it also apply to I/O & automobile motors?

When I charge my deep cycle battery (portable general purpose not onboard marine charger), I keep all my electronics hooked up to the battery (locator, radio, lights, etc). Is it okay to keep them all hooked up while charging?

[marine_man]

any suggestions on where to start or focus the efforts on?

I would wait until it does it again (doesn't work), then pull the dash panel off and get a test light or multimeter and verify that the ground is good to the tach, and where the tach ground comes from, then chase it back to the motor.

marine_man

[marine_man]

... sometimes they get blown if you charge the battery without disconnecting from da motor. good luck and dont throw the batteries

I have never heard of this - not to say that it's not possible, but not a frequent occurence - lots and lots of people have on board chargers that charge the starting battery as well with their charger without issues.... if you connect the charger backwards and then turn the charger on I'd believe it'd smoke the rectifier though.

marine_man

[NCLaker]

MM ... If you are ever in the Twin Cities area, let me know. With the all the "free" very helpful advice I have recieved from you directly/indirectly I owe you at least a few beers.

Same goes for the other boat/auto mechanics on this site that are willing to share their expertise with your fellow fishermen. I'm sure you and the others have saved countless $100-1000 of dollars by empowering us with knowledge to fix it ourselves or avoid costly extra charges at the shops.

You guys are AWESOME!!

[dougr1969]

All,

I second that 100%!

MM,

You bring up a good point. How can i find out if my 330 is on a switched circuit?

[marine_man]

Make sure all your switches are off and see if it will power up, including the GPS module. If it doesn't you're on a switched circuit. If it does it's time to re-wire the unit so it is on a switched circuit. Does your boat have any ACC switches?

marine_man

[pinkfloyd4ever]

I bought and installed one of those on-board chargers from Fleet Farm, it is the best investment I ever did, about $80. Get home, plug it in, and the batteries are all charged for the next time going out. Anyone else use these?

[marine_man]

Absolutely... on board chargers are the way to go in my opinion - a bit expensive, but well worth it when it comes to reducing hassle.

marine_man