Battery drain with Perko off

R

rocketfish

Recruit
Joined
Aug 17, 2012
Messages
3
With the perko switch off, I am getting a drain on my battery #2, resulting in <8V after a period of 4-5 days. Everything is wired in to operate on either batt, with nothing wired directly to the batteries. I tested for a short and I am not getting any feedback that would indicate a short in the system. These are brand new AGM batteries. The perko appears to be functioning properly, as nothing is drawing power with the switch off. Any other ideas? I am stumped on this one.
 
G

glenn property of pam

Commander
Joined
Feb 17, 2012
Messages
2,906
Re: Battery drain with Perko off

do you own a volt meter with amps on it. if you do turn off the perko and take the positive lead off the battery then set the meter to 10amp dc this will also be marked at the plugs on the meter to show you which plugs the leads go in. then connect one lead to the battery cable that you removed and one lead to the battery + post. this will tell you if there is any amps flowing from the battery. if you need more help take a good pic of the volt meter and the battery so we can assist you. if you find no amp draw then turn on the perko to bat 2 and add a small load like turning on the bow light the meter should read somewhere near a amp proving your meter hook up was correct. no draw indicates a battery problem a small draw indicates you may have something hooked up like a auto biege pump switch or radio memory somewhere.
 
D

dingdongs

Chief Petty Officer
Joined
May 29, 2009
Messages
649
Re: Battery drain with Perko off

try again and disconnect the earth from no 2 battery.in 4to 5 days then measure voltage.if its the same you definately have a duff battery.
 
W

Wind dog

Petty Officer 1st Class
Joined
Aug 13, 2012
Messages
304
Re: Battery drain with Perko off

dingdongs said:
try again and disconnect the earth from no 2 battery.in 4to 5 days then measure voltage.if its the same you definately have a duff battery.
Click to expand...

Is the top of the batteries clean?
Umm when did battery ground become earth?
 
R

rocketfish

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Joined
Aug 17, 2012
Messages
3
Re: Battery drain with Perko off

Well, I've run all sorts of draw tests, and nothing out of the ordinary. I've done everything I can think of short of tearing out the floor and tracing all the wires, but I am not detecting a short, so I don't think it is necessary. Here is my next question. Could my battery charger/maintainer be drawing enough out of the battery to cause this issue? I know there is a minor draw with all battery chargers when they are not in use, but I wouldn't think this to be a significant enough draw. However, I have had the charger disconnected for 3 days and the batteries are both holding the same charge as they were initially. I've never heard of such before, but could the plug of my battery charger be grounding out on the aluminum hull, drawing power out of my batteries?
 
Silvertip

Silvertip

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Joined
Sep 22, 2003
Messages
28,762
Re: Battery drain with Perko off

The ac plug on the charger is isolated from the output side of the charger and is not the issue. If the charger was allowing a discharge current to flow you could measure it with the plug disconnected. Disconnect the chargers positive lead from each batter and take a current reading in each. Shorts blow fuses. There is a difference between a slight current draw and short. Yes, it is very possible there is defective blocking diode in the charger. The purpose of the diode is to prevent a backflow from the battery when the charger is off and it may also be part of the circuitry to prevent damage from reversed polarity. Any defective circuitry in the charger may cause a reverse current flow. It all depends on where in the circuit the bad component(s) are located.
 
R

rocketfish

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Joined
Aug 17, 2012
Messages
3
Re: Battery drain with Perko off

Well, it's been 5 days and the batteries are still holding their charge. The charger has been disconnected the whole time. Ran an output test on the charger and was getting 0.00v out of all 4 leads :facepalm:. I believe the issue might be resolved. Thanks for all of your help.
 
U

UncleWillie

Captain
Joined
Oct 18, 2011
Messages
3,995
Re: Battery drain with Perko off

rocketfish said:
Well, it's been 5 days and the batteries are still holding their charge. The charger has been disconnected the whole time. Ran an output test on the charger and was getting 0.00v out of all 4 leads :facepalm:. I believe the issue might be resolved. Thanks for all of your help.
Click to expand...

Was the charger attached to the battery?
The better chargers will have ZERO output WITHOUT a battery attached.
You should see more than 13v with the charger plugged in and battery attached.
Expect 14-16 volts while charging, and 13.0 -13.5 while maintaining.

If the battery drops below 12.5 with the charger plugged in, there's your problem!
 
bruceb58

bruceb58

Supreme Mariner
Joined
Mar 5, 2006
Messages
30,478
Re: Battery drain with Perko off

Pretty easy to check if its the charger. Attach it without powering it up, put a multi meter in line and read the current.
 
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