Help Slow Battery Drain

[danger]

I recently replaced the old battery in my sled with a new Trojan starting battery. Seemingly beyond by control the battery is draining very slowly on its own.

I have checked and double checked to make sure everything is off(fish finder, bilge pump, lights...) I am at a loss. Could there be a short in the system somewhere that is draining the battery:help:. Or is it possible to have a bad battery.

I need some serious suggestions, the lives of winter steelhead are hanging in the balance.

Dan

[MattPark]

There can easily still be a draw. An easy way to check is to disconnect the battery and see if it draws down.

My guess is it won't. There is likely a draw somewhere. Disconnect the battery until you find the draw.

[danger]

Is it possible with a DMM to tell which circuit is causing the drain? Could a shop like ABE electric help me out?

Dan

[freespool]

The best way to find the problem is simple.
Disconnect the positive lead on the battery, get a ohm meter and select RX 1 or R times 1, now zero the meter.
Place one lead on the diconnected lead and the other on the negitive battery lead.
If there is a draw you will see meter deflection.
Now with the meter deflecting, pull your c/b's fuses one at a time, untill the deflection goes to zero, and that is the circuit that is drawning down the battery.
Caution, do not put the meter leads accross the battery while in the R times anything mode, disconnect the positive battery lead.




salmon hugger

[danger]

Aha. The resistance should be infinate on every circuit. A circuit with any measureable resistance is drawing current.

Can you buy an ohm meter at an auto parts store?

Thanks,
Dan

[freespool]

I think you can.
Good luck, let us know what you found.


salmon hugger

[trap50]

Bi MArt Joe's any place like that sells them.

[Ethical hunter]

I have had a slow dead draw on my battery going on two years and no one can track down the source. The guys at the shop put a quick dissconnect on the + terminal. So, now I just dissconnect the battery when not in use. I know its not a fix but its a band aid that works.

EH

[jimh]

I vote for the disconnect. That works even if you happen to leave something on.

[5 Salt]

GPS Attenna is a common source of drain.

Run all your assories and other items directly connected to the battery(s) into your battery switch and your problem is solved.

Remember however that even batteries sitting in the shop with nothing connected need a charge every 45-60days to maintain full charge and reach maximum battery life. Purchase a higher quality water proof charger to permanently mount in the boat. Quality chargers can remain plugged in continuosly without damaging batteries, will condition batteries as it charges, and will have distributed on-demand charging where by it distributes the unused portion of each bank's energy output to the next battery bank requiring additional amps, providing faster charging.

Cabelas ProSport Marine On-Board Chargers is a quality unit at a great price. Available for 1-3 battery systems.

[fishon_nehalem]

I like athe quick disconnect idea, there are a lot of advantages to that, safety being the main one. The advice on using the OHM meter is really, really good, I carry one in my tool box all of the time and have found problems that you would never think about. Another idea is check your grounds, floating grounds can do weird things. Above all else think safety even 12 volts can cause a lot of damage.
Good luck..............:)

[chucks electric]

hello, i think i'm going make some people angry on this one but here goes. never use an omh meter to test for a current draw as they can be damaged if or when they are connected to a hot circuit. leaking alternator diodes are often over looked. you need a low amp probe to properly check for current draws. using test lights can be misleading as they require low current to glow. some electronics have memory and by making a connection at the battery can cause a momentary spark and can lead you to think that you have found your gremlin. pulling fuses with the low amp probe connected will help locate the circuit. but that only works if everything is wired correctly. quick disconnects are not a good idea and a source of a fire quick disconnects wear and as they do they develop high resistance anywhere there is resistance there is heat especialy in a circuit with serveral hundred amps availible. install a battery switch. infact abyc and the coast both state that a battery switch be installed on any battery with more than 800 ca. the symptoms you are experiencing are the reason i have some many diagnositic tools. there is just no quick answer. if you would like i can take a look at it for you?

[1pump]

Ah, Chuck beat me to the alternator diode theory. I've had a couple go bad and start drawing between 2-3 amps from the battery, enough to kill it in 24 hours or so.
And he's right about the ohm meter. I use a DVM with a low amp function. The bummer with mine is that it's fused for 10 amps, like most DVMs. But most drains are less than that. A while back I was lucky enough to score a used digital AVR tester for cheap that can handle 1000 amps. It's already paid for itself in tracking down problems. :bowdown:

[vudo]

Here's how I found my current draw problem:

1. Invite a friend over for a beer
2. While he/she's over why not have him/her help you with the following
a. Change the test leads over on your DMM from the normal usage to measure current.
b. Make sure everything is turn off
c. Disconnect the positive terminal from the battery
d. Have him/her hold one test lead on the battery and the other on the cable you just disconnected
e. You should be getting a reading from the current draw
f. Have your friend keep and eye on the meter while you disconnect one fuse at a time

3. You can buy a DMM from Harbor freight on sale from $2.49 regular is less than $10 I think

This will guarantee to work. Feel free to PM me if you need help. I'm more than two hours from you, but will be more than glad to help any way I can through PM. This is what I do for a living.

[freespool]

hello, i think i'm going make some people angry on this one but here goes. never use an omh meter to test for a current draw as they can be damaged if or when they are connected to a hot circuit. leaking alternator diodes are often over looked. you need a low amp probe to properly check for current draws. using test lights can be misleading as they require low current to glow. some electronics have memory and by making a connection at the battery can cause a momentary spark and can lead you to think that you have found your gremlin. pulling fuses with the low amp probe connected will help locate the circuit. but that only works if everything is wired correctly. quick disconnects are not a good idea and a source of a fire quick disconnects wear and as they do they develop high resistance anywhere there is resistance there is heat especialy in a circuit with serveral hundred amps availible. install a battery switch. infact abyc and the coast both state that a battery switch be installed on any battery with more than 800 ca. the symptoms you are experiencing are the reason i have some many diagnositic tools. there is just no quick answer. if you would like i can take a look at it for you?


Chuck, the first thing I said was disconnect the battery positive lead, or damage to the meter will occure.
With a Simpson 260 it blows a fuse.



salmon hugger

[OutTrolling (ot)]

I use a master relay on the high side of the battery like is done in aviation. That disconnects all circuits off of the main buss line. (have worked in aviation for nearly 40 years) Never have had a problem doing it that way. I notice you mention a Simpson 260, Freespool. I also have one of my own, We have many of these in our avionics dept. Top notch meter.

[chucks electric]

i apologize i did not mean to imply that you would or did use your meter improperly but most boat owners dont use a higher end meter. my information was to inform those who are not electricians and who dont understand ohms law.

[freespool]

I use a master relay on the high side of the battery like is done in aviation. That disconnects all circuits off of the main buss line. (have worked in aviation for nearly 40 years) Never have had a problem doing it that way. I notice you mention a Simpson 260, Freespool. I also have one of my own, We have many of these in our avionics dept. Top notch meter.


I also worked in avionics for 30 years, and I found that trouble shooting intermitant problems was far easier with the 260 vs the digital meters.
It was also the first meter I used in the military, way back in the Skyhawk days.
I don't think there is a analog meter on the market, that can stand the abuse the 260 can take.


salmon hugger

[danger]

I need to check the current draw on my brain after reading all of the help you guys have given me. I am working on a few "leads":laugh: right now and will pm some of you if I need aditional help.

Thanks,
Dan