Again, car is a backup ride only so it sits for weeks undriven. Usually only move it when getting my rock crawling rig out of the garage for a wheeling trip. If I don't disconnect the battery and it sits for 2-3 weeks the battery is dead, so something is draining it and I'm clueless how/where to start......suggestions.
How to track down whatever is draining battery?
- Thread starter VIIIup
- Start date
Jamesvinar
New member
Thats normal
driller
El Presidente
I wouldn't necessarily say 2-3 weeks sitting would 'normally' drain the battery but you need to understand there is a constant drain and you can measure it with a DC ammeter that will measure in milliamps.
Billcu I know has measured this in detail before. There is a higher draw at first which is then followed by a lower amount of current.
If you discover a larger than normal current draw, you can generally find the source by methodically pulling fuses one at a time.
Also make sure no aftermarket devices are present and powered on with the key off, including cell phone chargers. I have a problem at times in my work truck with a radar detector I often leave 'plugged in' and a cell phone booster that I sometimes forget to turn off.
If you habitually leave the car unattended for weeks at a time, I highly recommend a trickle charger such as a Battery Tender unit. Or as you have discovered, you can disconnect the battery and it will usually last months instead of weeks.
Lastly, make sure your battery terminals and grounding points are clean and free of corrosion.
Billcu I know has measured this in detail before. There is a higher draw at first which is then followed by a lower amount of current.
If you discover a larger than normal current draw, you can generally find the source by methodically pulling fuses one at a time.
Also make sure no aftermarket devices are present and powered on with the key off, including cell phone chargers. I have a problem at times in my work truck with a radar detector I often leave 'plugged in' and a cell phone booster that I sometimes forget to turn off.
If you habitually leave the car unattended for weeks at a time, I highly recommend a trickle charger such as a Battery Tender unit. Or as you have discovered, you can disconnect the battery and it will usually last months instead of weeks.
Lastly, make sure your battery terminals and grounding points are clean and free of corrosion.
Jamesvinar
New member
If it were an older battery it would shorten the length wouldn't it. I remember reading something about Gen 2's having the anti theft take up alot of power causing death if it sits for a while, happened with mine over the course of 2 weeks
BlackIceLSC
New member
You can get a Battery-tender....not specifically that brand but any self-regulating trickle-charger will work.
we've installed the napa brand on numerous customer's cars through the years with great success.
you connect it to the battery and route a small connector out near the grill opening and leave it there permanently...then park where you can just plug it in to the "tender". all you have to do is remember to unplug it before you drive off...it feeds the battery only when the battery reaches a critical voltage, so it isn't "on" all the time.
or you can install a quick-disconnect to your negative terminal: just open the hood, unscrew the green knob and close the hood. screw the green nob back tight when you want to move the car.
I had a 5 year old battery in our 69 Roadrunner and forgot to disconnect it one winter. it sat for 5 months and fired right up, so it's not always the age of the battery but what the vehicle uses from the battery while sitting:
alarm/security system, "keep alive memory", modules, PCM/UCU's, radio (clock, pre-sets, etc), AIR SUSPENSION modules....anything that "stays alive" when vehicle is shut off.
we've installed the napa brand on numerous customer's cars through the years with great success.
you connect it to the battery and route a small connector out near the grill opening and leave it there permanently...then park where you can just plug it in to the "tender". all you have to do is remember to unplug it before you drive off...it feeds the battery only when the battery reaches a critical voltage, so it isn't "on" all the time.
or you can install a quick-disconnect to your negative terminal: just open the hood, unscrew the green knob and close the hood. screw the green nob back tight when you want to move the car.
I had a 5 year old battery in our 69 Roadrunner and forgot to disconnect it one winter. it sat for 5 months and fired right up, so it's not always the age of the battery but what the vehicle uses from the battery while sitting:
alarm/security system, "keep alive memory", modules, PCM/UCU's, radio (clock, pre-sets, etc), AIR SUSPENSION modules....anything that "stays alive" when vehicle is shut off.
There are also solar trickle chargers that charge continually as long as you have sun. If you park out side in the sun this is a decent option.
Otherwise, as people stated, modern cars continually draw a charge on the battery. Even when the car goes to sleep after an hour or so of no activity. Your battery may also be nearing the end of it's useful life if you are only getting 2-3 weeks. Remember too that frequently letting a lead acid battery sit for weeks without activity quickly degrades it through factors like sulfation, stratification, etc. Letting them sit for extended periods is the worst thing for a battery. A maintainer helps prevents this and keeps the charge. Even if you disconnect the battery you should use a maintainer if you want to maximize battery life. Giving the battery a good charge could make a big difference. Especially if you have access to a good charger that can sense sulfation.
Otherwise, as people stated, modern cars continually draw a charge on the battery. Even when the car goes to sleep after an hour or so of no activity. Your battery may also be nearing the end of it's useful life if you are only getting 2-3 weeks. Remember too that frequently letting a lead acid battery sit for weeks without activity quickly degrades it through factors like sulfation, stratification, etc. Letting them sit for extended periods is the worst thing for a battery. A maintainer helps prevents this and keeps the charge. Even if you disconnect the battery you should use a maintainer if you want to maximize battery life. Giving the battery a good charge could make a big difference. Especially if you have access to a good charger that can sense sulfation.
Jamesvinar
New member
That was my truck this winter too lol, Did need a little new gas in there but after that no problems.
MarkVIIIMarc
New member
Did someone above recommend pulling some fuses to see if that makes a difference then narrowing it down?
Yes, I've measured the current draw a few times.
It's always been normal on my cars, but I never tested it with the alarm set. I do let my cars sit for long periods so I do disconnect the batteries too.
The link below shows the results I had. If there was a large current draw, then yes, I would remove fuses and run the test again to narrow it down.
http://www.lincolnsofdistinction.org/vbulletin/showthread.php?42085-Battery-drain&highlight=drain
It's always been normal on my cars, but I never tested it with the alarm set. I do let my cars sit for long periods so I do disconnect the batteries too.
The link below shows the results I had. If there was a large current draw, then yes, I would remove fuses and run the test again to narrow it down.
http://www.lincolnsofdistinction.org/vbulletin/showthread.php?42085-Battery-drain&highlight=drain
My CE sat for 2 weeks. Battery condition/age unknown, came with the 94. All was well until it sat for 2 weeks. go to start it and nothing. Battery volts 9.2. Put charger on it for 3 min, and fired right up, putting out 14.4 volts from alt. Threw power pack in the trunk, and went to the car show. Made a few stops on the way home, and all was well, started each time. Took voltage at battery, and found this:
Sat 6:15 pm=12.45 volts
Sat 7:30 pm= 12.46
Sat 8:00 pm=12.46
Sun 9:00am=12.33
Sun 1:00pm=12.38
Mon 10:30 am=12.35
Tues 8:00am 12.34
Must have been something stuck to draw it down to 9 volts. I'll be at the dealer show Sat, and get a new one.
Sat 6:15 pm=12.45 volts
Sat 7:30 pm= 12.46
Sat 8:00 pm=12.46
Sun 9:00am=12.33
Sun 1:00pm=12.38
Mon 10:30 am=12.35
Tues 8:00am 12.34
Must have been something stuck to draw it down to 9 volts. I'll be at the dealer show Sat, and get a new one.