My starter battery drains!! Please help!

bass343 · Post by **bass343** » Sun Jun 16, 2019 10:56 pm

Fellow anglers,

I have been dealing with a battery issue on my legend V20 with my electronics and starter battery.

I've already gone through two starter batteries in the last two years. The cells are AGM's top of the line, the biggest group you could get.

For some odd reason, the power keeps draining my starter battery to the point it goes dead on me while on the water just after a few hrs. Something seems to be draining my starter battery, and I'm not sure why?

After a few hrs, I have to jump start my starter battery using my trolling motor batteries to start my engine.

Has anybody dealt with this issue? If so, what can I do to troubleshoot the problem? Any ideas would be helpful.

Thanks,

Dan

mark poulson · Post by **mark poulson** » Mon Jun 17, 2019 8:35 am

Sounds like you have a short somewhere.
Take it to a good boat mechanic, and figure it out before you spend more money on batteries.

WRB · Post by **WRB** » Mon Jun 17, 2019 11:41 am

Check your onboard charging system to see if it's fully charging the cranking battery.
Check your OB alternator output.
Check for any open switches, locker lights etc.
Your OB computer needs 12V to start the engine. If your electronics and livewell pump are drawing enough amps they can draw down a cranking battery lower then 12V. Some anglers have gone to a house battery to resolve this problem.
Tom

cdrake · Post by **cdrake** » Mon Jun 17, 2019 12:47 pm

Check to see if the rectifier (alternator) cable is connected to the proper battery terminal. My previous boat had a black cable w/ a red sheath at the end that needed to be connected to the negative terminal. While doing some maintenance I mistakenly hooked it up to the positive terminal which in turn drained my battery every time I started the engine instead of charging it. If caught in time you can avoid ruining the battery.

You may also want to consider installing a perko master battery switch to completely isolate/shut off power when not in use. A simple and cost effective fix ($20.00) for peace of mind.

WRB · Post by **WRB** » Mon Jun 17, 2019 3:08 pm

You would think a on/off battery switch and engine charging amp meter would be included with Legend boat dealer prep package?
Good point.....You need the battery switch to isolate the OB when charging using your onboard charger..
Tom

bass343 · Post by **bass343** » Mon Jun 17, 2019 3:44 pm

Thank you all who replied to my post. I now have some ideas about what could be the issue.

My boat does have a battery switch. I have to switch it on to use all my electronics. The one thing I noticed when charging is if I leave the switch on the battery does not get a full charge. But when I turn off the switch the battery does get a full charge.

It seems that when I leave the switch on during charging, it seems to drain during charging. And when I have the switch on while fishing it drains and dies after a few hrs.

Mitch · Post by **Mitch** » Mon Jun 17, 2019 5:37 pm

Test for a short circuit first. Use a test light by removing the Neg battery terminal and then hook the alligator clip to the wire and touch the neg post with the point of the light. If the light comes on, then you have a short somewhere. Attach the point to the terminal. I use a hose clamp and stick the point between the terminal and the clamp. So, now go to your fuse box and pull the fuses out one at a time. If the light stays on, replace that fuse and go to the next one. When the light goes out, that's the circuit that is bad somewhere. Test all of them just to make sure you only have one bad circuit. Now you have to start checking all connections in that circuit. If it's not a MAJOR circuit, I'd run with it for a day and see if your problem still exists. It can be a tedious task, but at least you have a starting place. Sometimes, it's easiest to just replace that whole wire run, like if it's the power wire to the fish finder, and wire it directly to the battery cut off switch.

stickbait · Post by **stickbait** » Mon Jun 17, 2019 6:15 pm

Mitch wrote:Test for a short circuit first. Use a test light by removing the Neg battery terminal and then hook the alligator clip to the wire and touch the neg post with the point of the light. If the light comes on, then you have a short somewhere. Attach the point to the terminal. I use a hose clamp and stick the point between the terminal and the clamp. So, now go to your fuse box and pull the fuses out one at a time. If the light stays on, replace that fuse and go to the next one. When the light goes out, that's the circuit that is bad somewhere. Test all of them just to make sure you only have one bad circuit. Now you have to start checking all connections in that circuit. If it's not a MAJOR circuit, I'd run with it for a day and see if your problem still exists. It can be a tedious task, but at least you have a starting place. Sometimes, it's easiest to just replace that whole wire run, like if it's the power wire to the fish finder, and wire it directly to the battery cut off switch.

Mitch is on the right track.... IMO.. you have a draw..not a short, a short will blow fuses and or melt wires, caused by hot/ground wire touching, pinched hot wire to metal..ect....... a draw pulls extra power from the supply..i.e. battery causing it do go dead quickly...light left on, solenoid stuck...ect... Test as Mitch advices with a test light is real guick and them track circuit by pulling fuses...

WRB · Post by **WRB** » Tue Jun 18, 2019 6:37 pm

bass343 wrote:Thank you all who replied to my post. I now have some ideas about what could be the issue.

My boat does have a battery switch. I have to switch it on to use all my electronics. The one thing I noticed when charging is if I leave the switch on the battery does not get a full charge. But when I turn off the switch the battery does get a full charge.

It seems that when I leave the switch on during charging, it seems to drain during charging. And when I have the switch on while fishing it drains and dies after a few hrs.

Are you sure you have a battery switch that switchs your cranking positive battery cable on/off?
This is a big switch, not a toggle or rocker switch.
Tom

bass343 · Post by **bass343** » Fri Jun 21, 2019 6:03 pm

stickbait wrote:
Mitch wrote:Test for a short circuit first. Use a test light by removing the Neg battery terminal and then hook the alligator clip to the wire and touch the neg post with the point of the light. If the light comes on, then you have a short somewhere. Attach the point to the terminal. I use a hose clamp and stick the point between the terminal and the clamp. So, now go to your fuse box and pull the fuses out one at a time. If the light stays on, replace that fuse and go to the next one. When the light goes out, that's the circuit that is bad somewhere. Test all of them just to make sure you only have one bad circuit. Now you have to start checking all connections in that circuit. If it's not a MAJOR circuit, I'd run with it for a day and see if your problem still exists. It can be a tedious task, but at least you have a starting place. Sometimes, it's easiest to just replace that whole wire run, like if it's the power wire to the fish finder, and wire it directly to the battery cut off switch.
Mitch is on the right track.... IMO.. you have a draw..not a short, a short will blow fuses and or melt wires, caused by hot/ground wire touching, pinched hot wire to metal..ect....... a draw pulls extra power from the supply..i.e. battery causing it do go dead quickly...light left on, solenoid stuck...ect... Test as Mitch advices with a test light is real guick and them track circuit by pulling fuses...

Yes, it's a battery switch. It's a large red switch.