Battery Drains While Boat Sits

[brichbk]

I went out with the boat the other day and found the starting battery dead. I went home charged it up, put the battery back in the boat fully charged. I went out the next day the motor started just fine. Motored to my fishing hole, shut off the motor, started the trolling motor (separate battery), then went back to head to another area and the battery was dead.

I purchased a new battery for the motor and installed it. The next morning I went to go fishing and the new battery was dead. The batteries keep their charge when not connected to anything.

It seems that something is draining my battery, what could it be?

The motor, lights, and fish finder all run off the starter battery.

I have a 1977 Johnson 70HP, the old battery was a "starter battery" w/ 460 CCA and the new one is a Deep Cycle battery with 575 CCA.

 

[Daviet]

Re: Battery Drains While Boat Sits

Disconnect all the wires off of the negitave battery cable. Use a 12V test light, Attach the clip from the test light to the battery post and touch the probe of the light to each wire, when the light lights you have found your draw.

 

[Rscardina]

Re: Battery Drains While Boat Sits

go through the wiring for each item..radio, fish finder, bilgepump, etc.. something is on...

if you have a battery swith then make sure its off...and then test everything..try turning on the radio, bilgepump, fish finder...etc

you should find something is still on one way or another

 

[brichbk]

Re: Battery Drains While Boat Sits

Disconnect all the wires off of the negitave battery cable. Use a 12V test light, Attach the clip from the test light to the battery post and touch the probe of the light to each wire, when the light lights you have found your draw.

Thanks for the help. I'll check it out tomorrow. There are only two wires connected to the battery so that should be easy enough.

 

[chadpcb]

Re: Battery Drains While Boat Sits

Disconnect all the wires off of the negitave battery cable. Use a 12V test light, Attach the clip from the test light to the battery post and touch the probe of the light to each wire, when the light lights you have found your draw.

I have to agree with Daviet. But that only isolates it to that wire, but doesn't isolate the problem. Now if that wire is connected to a neg. distribution block then you will have to do each wire on that distribution block. But to draw down a battery in 24 hours there has to be more than a 7 amp per hour drain.

First place I would look would be the power tilt and trim.
They use relays. It is possible for a relay to trip and remain tripped and permit a draw of amps and yet not function the T/T.

If you have an on board CD player that you turn off and on check it as well they draw about 10amps when running. Could have corrosion built up on the inside.

One last place I can think of and that is the Starter selonoid. Its just like the relays.

Just my .02

 

[d.boat]

Re: Battery Drains While Boat Sits

I agree with everything said. If you have two wires at your battery, one is the big one to the engine and the other is (probablY) a large, but smaller one to the main distribution block for everything that isn't run off your other battery. On mine it's stuff like the gauges, gauge lights, accessory socket, depth finder, etc.

I had a leak problem when I installed some new gauges and didn't know enough to power them through the key-switched power source.

 

[brichbk]

Re: Battery Drains While Boat Sits

the motor is on a 1979 Ranger and so it does not have any gauges, radios, or power trim/tilt.

One wire is the large one that goes to the engine and the other, I assume, goes to the fish finder but I'll make sure today.

I'll post after I get a chance to test the wires.

 

[jtexas]

Re: Battery Drains While Boat Sits

One wire besides the engine battery cable? That wire must be powering the fishfinder, lights and whatever else you have. Livewell pumps, bilge pump, horn. So there must be a fuse box.

If that accessory wire lights up the test light in Daviet's test procedure above, then start pulling fuses. When the light goes out, you've found your culprit.

If the engine battery cable lights up the test light, then first pull the main engine fuse (inline fuseholder, red wire, port side of the engine block close to the big red main wiring harness plug). If the light goes out, your drain is in the boat wiring harness, possibly the keyswitch.

If pulling the fuse has no effect, then disconnect the other end of the battery cable from the starter solenoid. If the light goes dark, replace the solenoid.

[note to chad: this is just for future reference...pre-80's 3-cylinder motors didn't have factory TNT but many were installed with an OMC aftermarket power tilt that doesn't use relays - the switch at the helm carries all the current. No fuse or breaker, either. Surprised me a bit, too. They are included in the "OB Accessories" section of www.shop.evinrude.com electronic parts catalogue. I don't know if any other models were ever similarly equipped.]

 

[brichbk]

Re: Battery Drains While Boat Sits

the small wire tested fine but the engine wire lit up...so now it's on to try jtexas' plan.

 

[jtexas]

Re: Battery Drains While Boat Sits

hold on...disconnecting the battery cable from the solenoid is not right...instead, disconnect the other red cable, the one leading to the starter motor. sorry about the mixup.

 

[brichbk]

Re: Battery Drains While Boat Sits

ok....so I've narrowed it down to the engine cable.

When I'm testing the solenoid am I supposed to have the positive and negative battery cable connected to the battery? I tried it with the light directly connected to the battery and with the light grounded with the negative battery cable connected to the battery and I got the same results. The light lit up

There is an inline fuse connected to the solenoid on the same screw terminal as the red cable marked "disconnect the battery before disconnecting the starter". This is the only inline fuse I could find. There is not one one the red wire coming from the battery to the solenoid.

When I pulled the fuse I tested both sides of the fuse container and the one connected to the solenoid lit up and the other side did not.

I disconnected the red wire going to the starter and no lights lit up (this was with the fuse in or out).

I'll post upclose pictures if it would help.

 

[jtexas]

Re: Battery Drains While Boat Sits

sorry my description may have been unclear. the fuse you found...it's on a wire running from solenoid to the big red plug, right? That is the only one on the motor. That's the 12V feed to the keyswitch.

Set up your test light just like it was earlier:
Negative cable on the neg battery post,
Positive cable disconnected,
Test light = clip on the battery (+) post, probe on the battery cable terminal. You'll need to affix it there (use a short jumper wire or aligator clip, or just tape it on there securely) or get a helper.

The light will be on at this point. Now, disconnect the fuse holder. If the light goes out, then you've narrowed the problem down to the boat wiring. That wire enters the big red plug where it is hooked up with a red wire w/purple tracer running to the keyswitch. From the keyswitch, it provides 12V to electric choke (purple/white wire), starter solenoid (yellow/red wire), overtemp warning horn (purple wire).

Reconnect the fuse holder (test light should come back on). Disconnect those three wires (purple, purple/white, yellow/red), one at a time. The test light will turn off when you disconnect the culprit. If the test light stays on with those three wires unhooked from the keyswitch, then the keyswitch itself is faulty.

If the light stays on with the fuse holder disconnected then you've ruled out the boat wiring, and it's on to the solenoid. Disconnect the cable running from solenoid to starter motor. If the light goes out, replace the solenoid.

 

[brichbk]

Re: Battery Drains While Boat Sits

Set up your test light just like it was earlier:
Negative cable on the neg battery post,
Positive cable disconnected,
Test light = clip on the battery (+) post, probe on the battery cable terminal. You'll need to affix it there (use a short jumper wire or aligator clip, or just tape it on there securely) or get a helper.

Daviet's test had the negative cable disconnected. Should I be doing these tests with the negative or positive cable disconnected on the battery?

 

[brichbk]

Re: Battery Drains While Boat Sits

Attached are two pics of what my engine looks like.

 

[Daviet]

Re: Battery Drains While Boat Sits

6 of one, 1/2 dozen of the other.
Do as jtexas describes to check the system, all comes out the same in the end, you find your problem.

 

[petryshyn]

Re: Battery Drains While Boat Sits

feel if the flywheel is warm after its sits for a few hours. If so you may have a shorted rectifier.....

 

[jtexas]

Re: Battery Drains While Boat Sits

starter cable

 

[brichbk]

Re: Battery Drains While Boat Sits

ok did as jtexas instructed and the light stayed on indicating the wiring was good. Tested the starter cable and the light went off, so tomorrow I'm off to pick up a new solenoid.

 

[brichbk]

Re: Battery Drains While Boat Sits

Replaced the solenoid today and connected the battery. I checked it 2.5 hours later and the battery was down to 60%, I started with a fully charged battery.

So I'm guessing it's not the solenoid. Could it be the starter or is it the wiring?

 

[Rscardina]

Re: Battery Drains While Boat Sits

try unplugging the big red plug at the engine. this should take all of the ignition out of the equation.

have you disconnected your accessories??..fish finder etc..??