[jtuber]

Wife went to lunch yesterday. She came back to work, forgot to turn off the car and walked inside (cell phone distraction). Later in the evening (4 hours later), she came out and was not able to start the car. She called and I was puzzled as to what the cause was. Since I wasn't there physically, I couldn't diagnose the issue. Later on, she had a coworker try jump start the car and it worked.

Why would leaving your car running deplete your car's battery? This is our first push-button start car. For a key-start car, this would empty out the gas tank eventually but I can't think of a reason for the CRV.

 

[319625]

If she left the car running, how was it off.
If she left it running... it would still be running(if gas wasnt depleted.
Sounds like she left it in accessory mode and that drained the battery

 

[williamsji]

Wife went to lunch yesterday. She came back to work, forgot to turn off the car and walked inside (cell phone distraction). Later in the evening (4 hours later), she came out and was not able to start the car. She called and I was puzzled as to what the cause was. Since I wasn't there physically, I couldn't diagnose the issue. Later on, she had a coworker try jump start the car and it worked.

Why would leaving your car running deplete your car's battery? This is our first push-button start car. For a key-start car, this would empty out the gas tank eventually but I can't think of a reason for the CRV.

Something does not add up here.

For a keyless entry system trim level....if you leave your car with the engine running.... and have the key fob in your possession... the vehicle will actually beep loudly at you as soon as you close the door. Also.. you cannot lock the vehicle in this state. Hard to miss it.. as it is loud and insistent. Not sure how it responds if the engine if off, but you put the vehicle in accessory mode.. as I have never tried that.

If you leave any accessories or in particular the lights on, and you turn the engine off and exit the car.. it will chime at you from the inside to warn you. Also pretty hard to miss unless outside noise is so loud it overpowers the cabin chime when you open the door.

It's pretty hard to walk away from a gen-5 CRV and not know you left something on.. because the CRV has multiple audible warnings to tell warn you about it. So something else must have happened in your wifes case... OR.. she ignored the vehicles warnings completely (which I doubt is the case though).

Does your wife normally leave the light switch on "Auto"? I'm thinking that if the off timers for Auto lights glitched out.. it would be possible that the lights stayed on.. but I have never heard of that problem with the gen-5.

Is the battery perhaps failing? Honda has reported some premature battery failures and has asked dealers to hold any bad batteries changed out under warranty so Honda can evaluate them for cause of premature failure.

Footnote: Also.. keep in mind... the Honda Dual charging system does not keep the battery at full charge when driving in low speed city conditions in modern Hondas ... more like 80% charge from personal observations... but I doubt that directly relates to what happened here.

 

[Carbuff2]

So something else must have happened in your wifes case... OR.. she ignored the vehicles warnings completely (which I doubt is the case though).

Unless maybe she was preoccupied (on the phone of catching up with texts). Don't forget, that is the age we live in! arn:

 

[robbyg]

If she left the car running, how was it off.
If she left it running... it would still be running(if gas wasnt depleted.
Sounds like she left it in accessory mode and that drained the battery

This sounds like the answer to me. No way would it have shut off by itself unless it ran out of gas.
She probably had in ACC mode with the stereo running and did not realize the engine was off.

 

[jtuber]

She told me she was on the phone and forgot to turn off the engine. If she was on the phone then it was likely she didn't have the radio blaring, I assume. But you guys could be right as well because I wasn't there. My assumption that she drove somewhere and came back but it could just be that she went to the car to have lunch and had the radio on. However, would a new battery be discharged that fast with just the radio and the panel on for 5 hours?

Have anyone had similar experience in walking away from your car w/o turning it off and then come back hours later?

 

[sirwired]

If she pushed the button twice without pressing the brake hard enough, that would drain the battery fairly quickly, as the ECU, fuel pump, electric P/S, and electric brake booster would all be powered.

 

[marty1]

This sounds like the answer to me. No way would it have shut off by itself unless it ran out of gas.
She probably had in ACC mode with the stereo running and did not realize the engine was off.

If left in IGN mode with engine off I could see the battery being drained.
But if left in ACC mode with engine off, there's an Automatic Power Off function to prevent battery drain. As noted in the Owners Manual:

If you leave the vehicle for 30 to 60 minutes with the shift lever in P and the power
mode in ACCESSORY, the vehicle automatically goes into the mode similar to
VEHICLE OFF (LOCK) to avoid the battery drain.

 

[williamsji]

........ would a new battery be discharged that fast with just the radio and the panel on for 5 hours?

Well the battery for CRVs in the US is a 51R and they generally are rated for between 32 and 40 amp hours (I've seen a few that were 45) for a flooded cell battery.... which means at 10 amps drain.... you have 3-4 hours before it's dead. I've seen some AGM 51Rs that are rated for 60 amp hours.. but they have their own issues with respect to discharges. Most 51Rs are rated for a reserve capacity of 85-100 minutes at 25 amp draw. With various systems running in the vehicle when it is not powered down... you could easily see 7-10 amps draw... which could deplete the battery low enough in a few hours that you cannot start the vehicle. And that assumes the battery was at full charge when she left the vehicle.. which is unlikely unless she was doing freeway driving or had the lights on or the fan at full blast. Most batteries in Hondas are probably sitting at 80-90% of full charge when you turn them off for the day.. courtesy of the low charge state the dual charge system puts them into at lower amp loads by the vehicle.

I really wish they would put bigger batteries in the modern Hondas.. given all the various electrical systems that come on and off when you enter and exit the vehicle (regardless if you actually start the vehicle).

Anyway.. I hope you solve the mystery... because if you are like me (a retired electrical engineer), it will drive you nuts not knowing.

 

[BBLee]

could it be that it is still in gear and she started to start it? and when her co-worker was jump starting her car, he instinctively put it in park and it started... ?

or, ... since there is no auto-shut off, and there is still gas, she might have turned off the engine but still in gear, but also left something on, like maybe the headlights was ON not in AUTO, or the door was ajar thus cabin lights are on...

 

[deedubb]

Perhaps she did leave it running & unlocked and a third party did things? Count your blessings the car was still there?

 

[rocky]

I did walk away from my 16 with engine running once. It shut off after ten minutes.
It might talk about this in the owners manual.

 

[jtuber]

I interrogated the wife. I had her sitting under a bright, harsh hot light on a hard chair while I was chilling in a comfy leather sofa, puffing cigars like a choo choo. In response to my barrage of questions, she adamantly said she left the car running because she just came back from lunch. So if the car did turn off, then wouldn't the accessories be turned off as well? Why was the car battery depleted?

She also mentioned that the flat screen went dark for a couple of days afterward when she was driving. She said she got a warning about "Anti-theft" system on the flat screen and something about pressing and holding the power button. She googled and found it to be the "radio" power button (not the start/stop button). She did that and the screen came back to life.

 

[Carbuff2]

^^^ LOL

Good thing she didn't admit to anything without her lawyer present... :beb:

 

[williamsji]

She also mentioned that the flat screen went dark for a couple of days afterward when she was driving. She said she got a warning about "Anti-theft" system on the flat screen and something about pressing and holding the power button. She googled and found it to be the "radio" power button (not the start/stop button). She did that and the screen came back to life.

This is completely normal if power is lost. Since she did have a dead battery, I would expect the anti-theft system would need a reset. Happily, we don't need a code anymore to unlock anti-theft on the HUs... it just pulls and validates the code from the car to identify that it is indeed the car it was installed in.

As for your wife's feedback to you regarding the actual issue ... I guess we all will probably never know the answer to this mystery.

 

[jtuber]

This is completely normal if power is lost. Since she did have a dead battery, I would expect the anti-theft system would need a reset. Happily, we don't need a code anymore to unlock anti-theft on the HUs... it just pulls and validates the code from the car to identify that it is indeed the car it was installed in.

As for your wife's feedback to you regarding the actual issue ... I guess we all will probably never know the answer to this mystery.

I'm so tempted to repeat this act to see what happened.

 

[Garfy]

If she pushed the button twice without pressing the brake hard enough, that would drain the battery fairly quickly, as the ECU, fuel pump, electric P/S, and electric brake booster would all be powered.

While the PCM, P/S module, etc. would be powered up, the fuel pump would not. The PCM would turn the pump on for 2 seconds on initial power up but unless it received an rpm signal, the pump would stay off as it did in all previous FI vehicles for the most part.

 

[jtuber]

Had the chance to drive the CRV recently and noticed that the average MPG went from 28.0 before this incident to 32.0 after the incident. No change in driving driving style/fuel/route. If anything I switched from premium to regular (experimenting to see if it helps with OD or not) before the incident and continued with regular after the incident. Very surprised. Not sure what to make of it at this point.

 

[Mike728]

Had the chance to drive the CRV recently and noticed that the average MPG went from 28.0 before this incident to 32.0 after the incident. No change in driving driving style/fuel/route. If anything I switched from premium to regular (experimenting to see if it helps with OD or not) before the incident and continued with regular after the incident. Very surprised. Not sure what to make of it at this point.

It's because your average was reset with the dead battery. I'm not sure where you live, but fuel economy improves with mild weather, plus Summer gas.