I have a 2007 honda pilot with 160K miles. 4WD. I have a battery that is dated 11/2017. I have had a problem lately where I will drive a short distance, park, and then be unable to restart the car. I have a jump starter in the car to get me home. I then have to recharge the battery. I had the battery and alternator checked by autozone and they say the battery and alternator are fine. I used a clamp on meter like you show on your video and I don't see a parasitic drain on the meter when clamped to the battery wire. What is going on with the battery? Am I just not recharging it enough becuase of less driving due to COVID?
Batteries don’t last more than 2-3 years these days. Test the battery with the digital tool, not the cheap analog ones.
Are you sure you don’t have any accessories left on with the car off like the dome light?
Thanks. I don't have any accessories on. The only thing I have is a cigarette plug adapter connected to a bluetooth speaker, but it has an LED on it that only turns on when the car is on. Otherwise, that should not be draining any power (I think). I had that for over 3 years plugged in that way too, so I don't suspect that as a cause of the drain. Any idea why the battery would check out OK at Autozone using their tools? They sent me on my way telling me the battery is good. They were using a pretty expensive looking digital tool with LCD display
Put a DMM (digital multi meter) in maximum amps setting between the battery terminal and the battery. Just watch the display when connected. after everything gets quiet and the car settles down from being plugged back in to the battery, watch the display. You should not see more than about 0.020 draw from the car. I think it should be less than that but some of these new cars have so much crap running in them that they can have draws double 0.020 amps or 20ma draw in them. I have seen them 40 or 50 ma in some cars. Like in a junk Jeep Grand Cherokee 2007.
If this draw is big like 150ma or 500ma, you can be sure it will take its toll on a 3 year old battery and flatten it overnight. Old batteries don't like being discharged like that and it usually is the beginning of the end.
Use the digital multi meter and find this power draw.
Put the battery terminal back on and then remove the fuses one at a time in the big box under the hood. Check the draw for each fuse with the meter noting how much power is being drawn at each position with the car turned off. Keep looking.
When you find the big draw, then look that fuse up in the service manual to find out what all circuits are on that fuse and its branch circuits. You WILL find that problem using that method.
Crappy car stereo installations were a big part of problems I found in used cars. I always looked at these since the stereo is attached to many power systems in a car and can be the source of a lot of tomfoolery.
I put my clamp on meter on and I watched the DC current reading. Over 5 minutes, the reading went from 0.005 A to over 0.020 A. This was after the car sat for a few hours and nothing had been turned on. Not sure why the current reading crept up.
I think I found the drain. It looks like the radio. I pulled the radio fuse and retested and the ammeter readings stayed below 12 mA. Does anyone know if honda radios are know for causing this problem?