How to find a battery drain

[DonTom]

You can check with many different phone apps on that Smartphone you wish was never invented I use Torque Pro and a ELM 327 Bluetooth adapter. Check monitors, read and clear codes, get freeze frame data, stream live data. I paid $5 for the pro version about 10 years ago.

Where possible, I use a laptop with that type of stuff, such as the one I am using now. I only use a smartphone when there are no other choices.

-Don- KIngsburg, CA

 

[John From Detroit]

You can check with many different phone apps on that Smartphone you wish was never invented I use Torque Pro and a ELM 327 Bluetooth adapter. Check monitors, read and clear codes, get freeze frame data, stream live data. I paid $5 for the pro version about 10 years ago.

I have the same app and device... NOTE: I have had it mess up my car (Unplugging the adapter fixed) on at least one occasion.. But it sure is handy to find out why ye bad light is on
And it lets me monitor a wide range of 'Other stuff" Chrysler does not think I'm interested in

 

[SpencerPJ]

It will be difficult to find the actual drain. It is difficult to pan for an emergency like you had, only way is to have a battery maintainer. Plan #2, disconnect the grounds. Your 2011 should have less of a relearn curve than current trucks.

 

[DonTom]

It will be difficult to find the actual drain. It is difficult to pan for an emergency like you had, only way is to have a battery maintainer. Plan #2, disconnect the grounds. Your 2011 should have less of a relearn curve than current trucks.

If I thought my key-out drain was too high, I would start with the fuse block with the key out and with the fuses that still have voltage I will remove, and then use one of these thingies.

 

[SpencerPJ]

True, but on my 2020 F150, just opening the door wakes up all sorts of electronics.

 

[bigbAZ]

True, but on my 2020 F150, just opening the door wakes up all sorts of electronics.

Just walking by with the key fob wakes up the new vehicles. Also, leaving the doors unlocked and the key fob nearby can cause battery sapping activity on some.

 

[klook]

I drive my Jeep about every day. No disconnect. But my 92 E350 ambulance has a battery disconnect built in and my 2004 E450 RV has one on the chassis and house battery. Everything else has a Battery Tender Jr.

 

[John From Detroit]

True, but on my 2020 F150, just opening the door wakes up all sorts of electronics.

Same on my jeep and some do not sleep,

 

[old_toys]

FWIW, if you have a Tekonsha brake controller, they are always powered. This is not noticed in a vehicle that is driven daily or every other day, but 2 weeks or longer not being ran and the battery suffers.
I keep my Tekonsha brake controller unplugged on the rear until needed.

my gmc Sierra duramax diesel only had a big battery drain once, it was after I installed the tekonsha brake controller and it was parked for 1.5 weeks. I now just leave it in its mount bracket and unplug the pigtail on the back and only use it when I'm pulling. never a problem after that.

 

[Camper2]

I had an alternator acting up on a bus one time and it drained the battery down over a few weeks. Took us months to find the problem. 8 weeks is a long time though.

I'd start with the tester listed above and check every fuse circuit.

 

[DonTom]

True, but on my 2020 F150, just opening the door wakes up all sorts of electronics.

Yeah, I have also seen that. That could be a problem because you want to check under the same load as when the car is asleep. The car turning on could even be the problem.

 

[DonTom]

I had an alternator acting up on a bus one time and it drained the battery down over a few weeks. Took us months to find the problem.

The most confusing problem I ever had was with a 1984 Van.

Nobody would every guess this one.

With a new alternator belt, works great for 100 miles, and then stops charging when lights are on. Every time, with a new belt. Belt just as tight after 100 miles, and made no noise.

The problem was the tranny dipstick tube! The tube ran just above the belt and had a small hole that could not be seen, as the small hole was on the bottom of the tube and leaked just enough oil mist onto the altrantor belt to stop the charging at around 100 miles later when the lights were on. It would still charge well enough when the lights were out. With the lights on, the engine would die in around 100 miles with a dead battery.

-Don- Needles, CA

 

[gwinger]

And that brand or a NOCO

I agree! The Harbor Freight and MOST of the ones on Amazon are not worth wasting your money on.
I have used the Deltran "Battery Tender" for years on my motorcycle, car and truck and my TT batteries.
I also agree that if a battery has been allowed to discharge below 50%, it may never recover fully.

 

[DonTom]

The Harbor Freight and MOST of the ones on Amazon are not worth wasting your money on.

The battery maintainers at HFT (other than their very cheapest one) have greatly improved over the years. They work fine, such as this one. Note the many 5-star reviews.

Same for Amazon, I use a lot of these on my motorcycles and Dodge Ram truck.

All of them charge to around 13.4 volts and then shut down, and then restart the charge at around 12.8 VDC and keep on doing such.

-Don- Maricopa, AZ

 

[John From Detroit]

I had an alternator acting up on a bus one time and it drained the battery down over a few weeks. Took us months to find the problem. 8 weeks is a long time though.

I'd start with the tester listed above and check every fuse circuit.

I had a car where believe it or not the alternator did not properly Ground (I mean it's BOLTED to the engine how could it not) Added a "Star" type lock washer and all was good.

 

[DonTom]

I had a car where believe it or not the alternator did not properly Ground (I mean it's BOLTED to the engine how could it not)

I had a similar thing happen with my Onan Generator years ago. See here.

Perhaps I should have changed the starter then, as it recently crapped out. But I have decided to junk the Onan in favore of my inverter generators, which I assume you read about here.

-Don- Maricopa, AZ

 

[jlhog]

I had a car where believe it or not the alternator did not properly Ground (I mean it's BOLTED to the engine how could it not) Added a "Star" type lock washer and all was good.

External tooth lock washers are commonly used in telecom applications to make a good ground.

 

[jlhog]

I have a 2011 Silverado 2500 Duramax. I put 2 new batteries in it last summer. Now just sitting in my garage while I’m in FL, the batteries will drain down to nothing after about 8 weeks. How would someone go about trouble shooting trying to find what’s causing it to drain. I think the clock in my radio and maybe the computer may have something to do with it. What else would do it. How can I locate any other draw.
I tried to find electrical cutout switches that I could put on one post of each battery, but because of the tight spaces, I couldn’t find anything that would work. I may have to keep looking

How to Detect a Power Leak and Prevent Battery Drain Issues

1. Prepare Your Vehicle: Turn off the engine, remove the keys, lock the doors, and disconnect any additional electronic devices.

2. Set Up Your Multimeter: Switch the multimeter to DC and select the highest ampere scale to prevent damage.

3. Disconnect the Negative Battery Cable: Use a wrench to safely disconnect the negative (black) cable, ensuring it doesn't touch the vehicle.

4. Connect the Multimeter: Attach the black multimeter probe to the negative battery terminal and the red probe to the disconnected cable.

5. Check the Multimeter Reading: If current is detected, there's a leak. A normal reading should be under 50 milliamps—higher indicates an issue.

6. Identify the Problem Circuit: Test the fuses one by one. When the multimeter reading drops, you've found the circuit causing the leak.

7. Fix the Problem: Inspect components in the faulty circuit for damage or loose connections. Repair or replace as needed.

Regular checks like this help avoid battery issues and ensure your vehicle's electrical system runs smoothly.

 

[gwinger]

External tooth lock washers are commonly used in telecom applications to make a good ground.

And put some battery terminal grease over the bolt and washer to protect it from corrosion. It's exposed to the elements.

 

[Rene T]

Thanks for the step by step instructions. For now, I’m just going to put the battery tender on and see what happens. I’m 1400 miles away from my truck so I’m just dependent on my grandson and my son in law to get the truck back home in the garage when they are done using it.
I’ll probably trouble shoot when I get home in May.