Battery drain when truck left idle for 7 days

howster · Dec 4, 2022

Hi,
I've a 2019 Ram 1500 Laramie and the battery drains to 5.75V after 7 days of no driving. I determined parasitic drain to be 1.3mA on mA multimeter dial setting and 0.245A on the A multimeter dial setting (shouldn't A be 0.130A given the mA to A conversion?) when faithfully following https://youtu.be/KF1gijj03_0 . That's what my multimeter returned in multiple tries! Attached is a pic of my multimeter dial settings.
Wondering how you interpret these settings and whether I need a new battery?
Truck battery is completely dead. Doesn't even attempt to start. 3 yr old battery, 30,000 miles.
Has happened 3 times in last 2 months. Nothing appears on in truck to justify the battery drain. Key fob 40-50ft from house
Thanks

RamDiver · Dec 4, 2022

I'd say your battery is toast but you may want to verify that your posts & clamps are clean & snug and that your alternator is functioning correctly and charging the battery.

When is the last time the battery posts & clamps were properly cleaned?
If it was longer than 6 months, start there.

These inexpensive cleaners are available from most auto parts stores & Amazon.
I try to clean mine and add a thin coating of dielectric grease, at least every 6 months.

My truck was new this past January and after sitting for a few cold days, I wasn't very impressed with the starting. I don't believe the Mopar batteries are known to be that great of quality or last that long. I'm already eyeing up a new AGM battery from Costco, you can't beat their warranty.

After cleaning the posts & clamps, have a volunteer hold the multimeter on the battery terminals while advancing the engine rpm from idle to about 1500 rpm. The voltage should increase to about 14-14.5 VDC. If this isn't happening, time for more troubleshooting.

Depending on where you live, 3 years might be the life expectancy for many batteries. I get temperatures from about -40F to 98F. Some batteries will last 5 years, but many don't.

I believe high heat such as in Florida or Arizona is the biggest killer of batteries but sitting in cold weather for longer periods always aggravates flakey batteries.

I have to get working on a big pile of wood in my backyard now, hopefully, someone else will point you in the right direction.

howster · Dec 4, 2022

Thanks. Yes I actually cleaned the poles with that very device and used the grease too. Did it about 6 months back when battery also drained out of the blue. No lights left on or anything to justify the battery drain. I charged the truck battery overnight back then for 24 hrs or so to recover it. Once truck is jumped it charges up to 12V+ on memory pretty quick. Live in MA so cold winters. AAA called so will likely replace the battery if they advise it after inspection.

White six four · Dec 4, 2022

If it's going to sit for more then a few days in the cold I'd recommend getting a battery tender for it. If I don't use my truck every day now that it's winter it gets plugged in to the tender then whether it's the following day or the following week I know the battery will at least be fully charged and ready to go when I need the truck.

Wild one · Dec 4, 2022

howster said:
Thanks. Yes I actually cleaned the poles with that very device and used the grease too. Did it about 6 months back when battery also drained out of the blue. No lights left on or anything to justify the battery drain. I charged the truck battery overnight back then for 24 hrs or so to recover it. Once truck is jumped it charges up to 12V+ on memory pretty quick. Live in MA so cold winters. AAA called so will likely replace the battery if they advise it after inspection.

If the battery is reading under 12.6 volts,it's techinically dead. 6 cells in a 12volt battery,and each cell should read between 2.1 to 2.2 volts which is 12.6 to 13.2 volts,anything under 12.6 and odds are you need a new battery

howster · Dec 4, 2022

Thanks for the feedback everyone. AAA just came and jumped the truck. His devices determined the alternator and battery is ok and something must have drained it. The mystery continues. Wil check voltage daily.to see if the drain is gradual. Will look into a tender. Thanks for all the advice. Will report back. No internal or external lights were left on. My wife's Durango has none of these battery drain issues so wondering the impact of temperature.

NETim · Dec 4, 2022

1.3ma is 0.0013A. Judging by the pics of the DVM you posted, the max current the ma setting on that DVM is 600ma. Use the "ma" jack and the "ma" setting on the dial when measuring an expected current of less than 600ma.

howster · Dec 4, 2022

So just tested the parasitic drain again after running the engine for 40mins. Engine off and the parasitic drain is 4.5 A which explains the battery draining over time. Battery voltage when running is 14.5V and off it's 12.99V. I have an after market truck topper with electric for the topper rear window lights and an accessory for cigarette lighters - see attached. LED always on but surely they don't consume much. The parasitic drain value dropped off to 1.6 A from 4.5A after a few minutes whatever that may mean. Everything in truck was off. I hate popping out fuses especially in the engine fuse box. Is there a fuse that's usually the culprit? Wifi or audio? I also just cleaned the poles with a pole brush and added the dialectic gel. Thanks.

NETim said:
1.3ma is 0.0013A. Judging by the pics of the DVM you posted, the max current the ma setting on that DVM is 600ma. Use the "ma" jack and the "ma" setting on the dial when measuring an expected current of less than 600ma.

Thanks!

NETim · Dec 4, 2022

Unfortunately, it's going to be a process of elimination to find this fault. 1.5A is a significant load that will obviously drain your battery fairly quickly. If this condition persists (1.5A draw), count yourself lucky. It will be that much easier to isolate and correct the problem. Intermittent problems can be difficult to locate.

Pull fuses. Disconnect stuff. Good luck!

howster · Dec 4, 2022

Thanks. Will report back. Trailer, topper and radio fuse will be the first 3 I'll test. Crazy how all this stuff starts shortly after warranty expiring. Murphy's law!

White six four · Dec 4, 2022

The reason the draw was less after a few minutes is the truck "went to sleep". When you do you're testing make sure the truck is in sleep mode. Not sure how long it takes for the truck to go into "sleep mode" but I would think after 5 or 10 minutes after turning it off would be enough. Good luck finding the culprit.

NETim · Dec 4, 2022

I've got a buddy with an older Chevy fighting an intermittent issue along these lines. It started about the same time the passenger side door lock went bad. My working theory is the body computer is trying to pull the solenoid and lock the door but can't for whatever reason. The body computer is waiting for the status to come back informing it that the lock is locked but since the lock isn't locking, the body computer isn't going to sleep.

ipstrategies · Dec 5, 2022

Check the headlight switch, I just sold my 99 Durango (had it for 20 years) the last couple years it would sit for months at a time and I noticed the battery would go dead. I noticed the dimmer dial for dash lights and dome light would flicker so I started tuning it all the way down (off) and no more issues. I just picked up a rust free 2000 Ram 1500 with 350,000 mile that seems to have similar issue so I picked up a switch at pull a part.

RamDiver · Dec 5, 2022

howster said:
Thanks for the feedback everyone. AAA just came and jumped the truck. His devices determined the alternator and battery is ok and something must have drained it. The mystery continues. Wil check voltage daily.to see if the drain is gradual. Will look into a tender. Thanks for all the advice. Will report back. No internal or external lights were left on. My wife's Durango has none of these battery drain issues so wondering the impact of temperature.

Regardless of what you may discover as the source of your parasitic load, discharging most lead acid batteries to anything under about 10.5 VDC is a certain death sentence. In your original post, you indicated 5.75 VDC, which is miles below 10.5 VDC.

If you live in an area that doesn't get too cold (not like you & I), you might get away with using a smart charger to rejuvenate and de-sulfate your battery and might squeak a bit more life out of it.

I had a similar discharge issue years ago on my Tundra. I did successfully rejuvenate the battery with a smart charger and all appeared fine until the first time the truck sat for a few days in early winter.

The battery was unable to start my truck without a short charging session after sitting in cooler weather, not even close to mid-winter temperatures yet. I replaced the battery and accepted that my parasitic load episode toasted the battery.

It sucked but having a reliable ability to start my truck in the winter is far more important than the cost of buying a new battery. And, I had a small car, that was mostly available that I could use to boost. That was more of a PITA than buying a new battery.

At 5.75 VDC, I'd say you're there already.

If you do decide to buy a new battery, don't waste your money on a Mopar battery. I wouldn't even bother with a free warranty replacement, starting is too important, and being stranded is a huge PITA.

I'd bet there are many threads here discussing the best options for battery replacement. Many users in colder climates have been very happy with installing AGM batteries, that's my plan when my Mopar starts to struggle.

.

97RedRam · Dec 5, 2022

I had that problem on my 97 1500. Turned out to be the glove box light was staying on even when the door was shut. I adjusted the switch and the problem went away. You cannot always see the light is on in the daylight. I saw it one night while it was dark.

howster · Dec 10, 2022

Hi,
So watched this https://youtu.be/rVScppKsfHs and checked for parasitic drain allowing all the internal lights and systems to switch off about 5 mins. The amp reading drops and holds at 0.114 Amps. This drain however is enough to kill my car battery if unused for 4 days. I took every engine fuse out 1 by 1 but reading didn't drop. I can't find the door jam switch / sensor to disable the interior systems from activating to begin the fuse removal check on the interior. Once the door is moved at all (even after being slightly ajar for 10 mins ) the inner systems fire up creating high voltage. Anyone know how to disable the door switch/sensor to prevent the systems turning on? I can't see a mechanical switch on the door or in latch so assume it's a fandangled motion activated sensor.
Thanks

chopperman1 · Dec 10, 2022

Parastic draw measuring is increadibly difficult these days using the traditional inline ampmeter. As soon as you connect the meter the systems awaken and can take 10min, 20min, sometimes even longer. You really need to use a tool like an amp hound. Let the truck sit over night with the hood open, don't want to trip anything that causes anything to turn on, no fob near the truck, nothing. https://duckduckgo.com/?q=amp+hound&ia=web

howster · Dec 10, 2022

RamDiver said:
Regardless of what you may discover as the source of your parasitic load, discharging most lead acid batteries to anything under about 10.5 VDC is a certain death sentence. In your original post, you indicated 5.75 VDC, which is miles below 10.5 VDC.

If you live in an area that doesn't get too cold (not like you & I), you might get away with using a smart charger to rejuvenate and de-sulfate your battery and might squeak a bit more life out of it.

I had a similar discharge issue years ago on my Tundra. I did successfully rejuvenate the battery with a smart charger and all appeared fine until the first time the truck sat for a few days in early winter.

The battery was unable to start my truck without a short charging session after sitting in cooler weather, not even close to mid-winter temperatures yet. I replaced the battery and accepted that my parasitic load episode toasted the battery.

It sucked but having a reliable ability to start my truck in the winter is far more important than the cost of buying a new battery. And, I had a small car, that was mostly available that I could use to boost. That was more of a PITA than buying a new battery.

At 5.75 VDC, I'd say you're there already.

If you do decide to buy a new battery, don't waste your money on a Mopar battery. I wouldn't even bother with a free warranty replacement, starting is too important, and being stranded is a huge PITA.

I'd bet there are many threads here discussing the best options for battery replacement. Many users in colder climates have been very happy with installing AGM batteries, that's my plan when my Mopar starts to struggle.

.

Thanks very much. Looks like it's time to get a new battery so if the voltage drops that low. Appreciate the advice! Will try and get an AGM instead of the Magneti Marelli Mopar one that came with the truck. I thought the AAA guy would've suggested a new battery when he came to the house and jumped the truck. I told him about the 5.75VDC too and that the battery draining was a recurring event. He ran a few tests with a special meter and specifically stated the battery was fine. I guess my concern is forking out a $250 for an AGM battery if the parasitic drain of 0.114A measured today drains the new battery too. Guess I'll find out when I put a new battery in. It would seem the logical way to go if a voltage <10V screws up a battery. Learning as I go. Will get the auto parts store to test the battery before replacement too to get their take. Will report back to help others . Thank you!

howster · Dec 10, 2022

97RedRam said:
I had that problem on my 97 1500. Turned out to be the glove box light was staying on even when the door was shut. I adjusted the switch and the problem went away. You cannot always see the light is on in the daylight. I saw it one night while it was dark.

Thanks I'll check it out. Much appreciated.

howster · Dec 10, 2022

NETim said:
I've got a buddy with an older Chevy fighting an intermittent issue along these lines. It started about the same time the passenger side door lock went bad. My working theory is the body computer is trying to pull the solenoid and lock the door but can't for whatever reason. The body computer is waiting for the status to come back informing it that the lock is locked but since the lock isn't locking, the body computer isn't going to sleep.

Will do, thanks. Will report back.

Battery drain when truck left idle for 7 days

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