Cranking battery current draw. HELP

[Lake]

Something is drawing current off my cranking battery while parked at home. I have gone through all the basics. How do I find ou what is drawing the power. I heard by using a volt meter will help me locate it. Anyone know how to do this? I have the graphs, motor and all boat functions hooked to it.

[blkdog812]

it could be several things. do you have a automatic float bilge switch, smart craft gauge, clock . it hard to say what is drawing the power. try checking the power out side of all your switches and see if there is power passing thru them when they are in the off position. you should also think about putting in a perko switch and kill all power from the crankin battery when storing or sitting.

[davet.]

First off, how old is the battery and do you leave it discharged for days after use? This will kill a battery and it won't hold a charge....period.
If it's fairly new, contacts are clean and it's been treated right, it goes like this:
Connect an amp meter usually in series (unless it's the clamp type) to the hot side of the battery and observe the amp draw. Start disconnecting sections of your circuits. Watch for the amp draw to drop off drastically every time you disconnect a section.
A good place to start is the main power switch. If you have access to the breakers, start disconnecting breaker leads until the amp draw stops. This should really help isolate the problem area.
If you suspect a certain wire is frayed and grounding and want to replace the wire and it runs thru inaccessable areas, disconnect the battery, cut the wire, tape a new wire to the old wire very tightly, then go to the terminated end of the old wire, disconnect it and pull it out while it pulls the new wire into place. Make good connections on both ends and retest.
Hope this helps, if not.....Call Mike at C & C.

[swordfish]

I was thinking weak battery or frayed wire ..ground problem as well perhaps a loose conection just guesses I am no mechanic, davet seems to have good knowledge. good luck to ya..

[Rich461]

Being a boat and car mechanic I can think of some things to start with.
1. Unhook all positive cables from the battery.
2. Hook an amp gauge between the battery and the device you are hooking to the battery.
3. If you see the needle move, then there is a draw on that device.

In this day and age of computers and stuff, some of then keep drawing power even when the key is off. So check your motor.
I have seen starting solenoids do this when they are going out. They short just a little bit, but enough to draw the battery down.
If you have a power outlet under the dash, those can cause this problem.
A faulty key switch can do this. Rust on any connection can do this. IF you have an onboard charger, they can do this. Water pumps in
the boat are good for this problem. They seem to short so slightly that they just draw a small amperage but not enough to blow the fuses.
Run across the fuse box (if you have one) with a gauge and see if any thing shows up.
The one thing you can do is to put a shut off between the battery and all devices hooked to it. A good cheap shut off switch is a replacement
keyed start switch for like an older car. The old foot dimmer switches work great and can handle a lot of amps.
You don't need to buy that big round red one for $30 or more. Anything that is marked 30 AMP or more will work. Just be sure to use the
appropriate connector on the end of the wire.
But you really should try to find the problem, by using a voltmeter and hooking up the wires one by one.
I once found a wire that had vibrated against a screw for a long time. It wore thru the covering and shorted against the grounded screw.
It took me forever to find that voltage drop but I finally did.

[ken a]

I had this problem after hooking up the gps pod without a shut off switch. Installed a shut off switch and ended the battery drain. Not saying this is your problem. Most boats have a fuse panel and a good place to start. Good luck.

[meanstick]

Do you have lights in your rod compartments? Check them.

[toddmc]

Do you have lights in your rod compartments? Check them.

Stuff moving around your compartments can turn on your lights. My last boat did this all the time. Also, always install a Perko shut off switch for your cranking batteries and another for your trolling motor batteries, and use them. I was told that leaving your power on can also be bad for your wiring. I eliminate all charging and discharging worries when I turn off my switches.

[Lake]

you guys rock. Thank you all very much. This is exactly the type of info I was looking for.

[Smee Again]

I had this problem after hooking up the gps pod without a shut off switch. Installed a shut off switch and ended the battery drain. Not saying this is your problem. Most boats have a fuse panel and a good place to start. Good luck.

That is a GREAT place to start. If you have a GPS, check this first!

SA

[TeamBeefmaster]

looks like u got some great info. my advice is try to find someone who is good with DC circuits to help diagnose it, buy them a case and have them help!! There are a lot of possible reasons this is happening, a wire being worn and shorting to ground, a bad switch, gps puck/structure scan module staying on, etc... but it could be ur battery or charger!!

the issue is that you may need to disrupt the circuits to troubleshoot them. if u check voltage u need exposed leads/connections and access to ground/negative. Not always the case in some switches and connections.... If u check current u need to put ur meter in line with the connection... unless u have or can borrow a sensitive current clamp (which is ur best option in doing it urself). If u start cutting wires to trouble shoot them ull have more problems than when u started.

****** Before u start messing with things, put the meter across ur charged battery. It should read 12.6-12.9 volts. If it doesnt, it may be ur charger or your battery is unable to hold a charge. Next, wait a few days or even a week without charging or using your boat. Just letting it sit. Check the voltage again, If it drops more than 0.15 volts start doing a colonoscopy on ur wiring with ur buddy who just got a free case good luck!!