Car battery dying repeatedly

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CarNewbie9

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great news!

clamp meters are a little more challenged with respect to accuracy but maybe this will not matter if you are noticing big differences. I do most of my testing with in-line meters but also have experience with current clamps and probes here at work. I guess another way to state this is that they can both be accurate but a current clamp will be more expensive.

of course the clamp meter is much more convenient so hopefully this works for you.
great news!

clamp meters are a little more challenged with respect to accuracy but maybe this will not matter if you are noticing big differences. I do most of my testing with in-line meters but also have experience with current clamps and probes here at work. I guess another way to state this is that they can both be accurate but a current clamp will be more expensive.

of course the clamp meter is much more convenient so hopefully this works for you.
Originally I was going to skip the amp clamp and go with just the in- line meter you mention. However, the YouTube video above includes what seems like a great method, using both. The idea is to test the amp drop across the fuses only when the amp clamp shows a spike in amps. I think this will help me narrow down the problem fuse.

 

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wow this has been quite an experience for you.
My '16 CPO was having issues last year when it would not start after driving it to the store. I jumped-started it and checked the voltage and it worked just fine a month or so until again it wouldn't start this time it was parked overnight.
Anyways I bought a new battery from AutoZone and I have not had any issues since.

Best of luck to you
 
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wow this has been quite an experience for you.
My '16 CPO was having issues last year when it would not start after driving it to the store. I jumped-started it and checked the voltage and it worked just fine a month or so until again it wouldn't start this time it was parked overnight.
Anyways I bought a new battery from AutoZone and I have not had any issues since.

Best of luck to you
Yes, I don’t think it should have been so difficult haha. Once I find the drain I still have to convince the dealership to fix it, which might be the biggest challenge of all.

I was hoping it was just the battery in my case too, but I’ve been tracking the voltage daily and it seems to be draining faster and faster. You lucked out!
 
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We isolated the problem to fuse 18- “back up”, located under the hood. I know from watching a YouTube video linked below it controls a lot of things.

We used the fuse pulling method. When we pulled fuse, the draw dropped from 600-700 ma to 20-30 ma. Huge difference! We decided to leave the fuse out overnight to see how high the battery charge stays. We have video proof of everything so I really hope the other dealership can help. Thanks everyone for all the help and advice!

 

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great! too bad you guys cannot pay yourselves $100 per hour for this diagnosis.

https://www.civicx.com/forum/threads/parasitic-current-drain-suggestions-needed.47743/post-782063

it is curious that the dealer tech. couldn't find a drain but I guess that means it is intermittent. sorry to bring up the basics but I think it would be a good idea to double check all of the USB connections and the 'cigarette lighter' power outlet. Make sure there is nothing plugged in and even that there isn't something left inside any port. check that all the windows work properly, the moonroof, overhead light,... and is there a light for the mirror on the passenger sun visor? the current draw is kind of large so I don't exactly think a little light would draw that much, I am just spitballing ideas. It could end up being tough to troubleshoot if it is some microcontroller operated module that is not properly going to sleep. I would hope dealer techs would understand a little more about how to narrow it even further at various body electrical system connectors.
 
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great! too bad you guys cannot pay yourselves $100 per hour for this diagnosis.

https://www.civicx.com/forum/threads/parasitic-current-drain-suggestions-needed.47743/post-782063

it is curious that the dealer tech. couldn't find a drain but I guess that means it is intermittent. sorry to bring up the basics but I think it would be a good idea to double check all of the USB connections and the 'cigarette lighter' power outlet. Make sure there is nothing plugged in and even that there isn't something left inside any port. check that all the windows work properly, the moonroof, overhead light,... and is there a light for the mirror on the passenger sun visor? the current draw is kind of large so I don't exactly think a little light would draw that much, I am just spitballing ideas. It could end up being tough to troubleshoot if it is some microcontroller operated module that is not properly going to sleep. I would hope dealer techs would understand a little more about how to narrow it even further at various body electrical system connectors.
I’m shocked the Honda techs couldn’t find it as well. I also assumed the draw would be small and intermittent but it appears to be large and constant. I really, really hope the techs at the other dealership can find the problem and fix it. I made an appointment for Wednesday morning and described my test results in the online form. Side note that I discovered yesterday the dealership I’ve been going to dented the top of my battery with the way they installed it. They also stained my seat and door, so I have hope this isn’t the norm for every dealership.

It almost seems like the car isn’t going to sleep at all. I’ve checked to make sure all lights go off (including in the trunk, glove box, and mirrors). I’ve been unpluggingmy phone charger and closing all charger covers each time I turn off the car. The moon/ sunroof controls all seem to work. I will double check everything today though.

The door handles do sometimes act strangely. Sometimes all handles unlock when the key is near, and sometimes only the driver one does. I never have to press the button on the door to unlock when the key is near. Note the unlocking info doesn’t apply when the battery is too low, I have to use the physical key or at best the unlock button.

I tried to use remote start a few times and couldn’t get it to work. I gave up since I don’t live in a very cold area. Seems like there could be something with the door handles and remote start
 

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The door handles do sometimes act strangely. Sometimes all handles unlock when the key is near, and sometimes only the driver one does. I never have to press the button on the door to unlock when the key is near. Note the unlocking info doesn’t apply when the battery is too low, I have to use the physical key or at best the unlock button.

I tried to use remote start a few times and couldn’t get it to work. I gave up since I don’t live in a very cold area. Seems like there could be something with the door handles and remote start
this is a giant clue. Do you have both of your key fobs or does one happen to be lost? there is different behavior if one key is outside the car and the other inside.

I think the little button on the door handle is to *lock* the car, not to unlock. Proximity of the fob is what allows it to unlock. my car isn't here right now or I would double-check this.

I use remote start a lot. With the fob, I press LOCK two times. Followed by holding down the start button for 4+ seconds. I guess if that system does not work then there is something wrong in those systems or with the door hardware.
 
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Great news! The other dealership found the problem and they’re fixing it under warranty!

They took my evidence to heart and tracked the draw on fuse 18 down to the passenger side door. It’s malfunctioning and keeping the security system awake 24/7. They’re going to replace the door handle under warranty. They’re also going to make sure that fixes remote start function.

A lot of money and time was spent to get to this point but I’m so relieved. Now to leave the first dealership a terrible review. :)
 

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Well I'm impressed. You stuck with it and found the real problem. My lazy ass would have just replaced battery only to find out new one is getting drained.
 
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I’ve been continuing to track the battery voltage to make sure the issue is fully fixed. Interestingly the battery seems to really like to sit at 12.2-12.3 volts. As someone here pointed out, this is considered normal in tech books.

The charge drops to 12.29 volts after sitting 24 hours. It drops much more slowly after that. I just checked it after ~68 hours (the longest it has sat since being fixed) and it’s at 12.22. Previously I was able to start the car as low as 11.99 volts, so I guess this is okay.

 
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