Battery died - Strange Charging System

[10GenPearlSi]

I drove home at night and 4 hours later my battery was dead. I jumped my car the next morning and started monitoring the battery voltage. Idling I see that the battery voltage is about 14.4V. While driving I see the voltage drops from 12.3V to 12.5V. I don't get any charging errors on my dash. I noticed a 10th gen Civic on You Tube had a TunerView recording. That one also ran 14.4V idling. When it drove around it would vary from 12.8V to 13V. I am very confused. Does anybody know what is going on? I have a dealer appointment Thursday.

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[360glitch]

I drove home at night and 4 hours later my battery was dead. I jumped my car the next morning and started monitoring the battery voltage. Idling I see that the battery voltage is about 14.4V. While driving I see the voltage drops from 12.3V to 12.5V. I don't get any charging errors on my dash. I noticed a 10th gen Civic on You Tube had a TunerView recording. That one also ran 14.4V idling. When it drove around it would vary from 12.8V to 13V. I am very confused. Does anybody know what is going on? I have a dealer appointment Thursday.

My understanding is that it does that to save fuel.

 

[10GenPearlSi]

My understanding is that it does that to save fuel.

Isn't 12.3V too low?

 

[360glitch]

Isn't 12.3V too low?

Not really, it’s a 12v system.

 

[calonzo]

I drove home at night and 4 hours later my battery was dead. I jumped my car the next morning and started monitoring the battery voltage. Idling I see that the battery voltage is about 14.4V. While driving I see the voltage drops from 12.3V to 12.5V. I don't get any charging errors on my dash. I noticed a 10th gen Civic on You Tube had a TunerView recording. That one also ran 14.4V idling. When it drove around it would vary from 12.8V to 13V. I am very confused. Does anybody know what is going on? I have a dealer appointment Thursday.

I vaguely remember a post about a loose ground wire on these cars. I can't find it though. Mention it to the dealer to see if they are aware of it.

 

[10GenPearlSi]

I took my car to the dealer. The car almost didn't start. It read 14.4V for the 30 minute drive up there. It must have an emergency mode where the alternator runs all the time if the battery tests low. Needless to say the battery was fully charged and read 12.7V when I got to the dealer. They tested everything and it tested OK. After hearing my story, they decided to replace my battery anyway. It read 14.4V all the way back home too. I guess when it sees the battery is OK it will drop to 12.9+-V when running.

They also suggested that I hit the lock button twice when I walk away to hear a beep and the car is supposed to go into a sleep mode soon to reduce parasitic drain.

 

[250GTCalifornia]

They also suggested that I hit the lock button twice when I walk away to hear a beep and the car is supposed to go into a sleep mode soon to reduce parasitic drain.

Is there any truth behind this? What about pressing the lock switch on the driver's side door?

 

[calonzo]

I took my car to the dealer. The car almost didn't start. It read 14.4V for the 30 minute drive up there. It must have an emergency mode where the alternator runs all the time if the battery tests low. Needless to say the battery was fully charged and read 12.7V when I got to the dealer. They tested everything and it tested OK. After hearing my story, they decided to replace my battery anyway. It read 14.4V all the way back home too. I guess when it sees the battery is OK it will drop to 12.9+-V when running.

They also suggested that I hit the lock button twice when I walk away to hear a beep and the car is supposed to go into a sleep mode soon to reduce parasitic drain.

Did you ask about a loose ground wire issue?

 

[10GenPearlSi]

Is there any truth behind this? What about pressing the lock switch on the driver's side door?

I have it set to lock the doors when I walk away, however they said that there are a lot of controllers in the car that will go to sleep if I double tap the lock fob. That way they won't be awake to drain the battery. I don't have any data to say if they lied.

 

[10GenPearlSi]

Did you ask about a loose ground wire issue?

I forgot to ask. All I did was describe the symptoms. I tried not to tell them solutions.

 

[elykoj]

happened to me, I was at work. I went to lunch around 2pm, came back, went to go home at 6PM and the car was completely dead. Honda charged it up said no faults or errors.. this was in the summer but hasn't happened since.

 

[aeonixx]

Happened to me as well. Where do you keep you key FOB? Keep it away from you car. I would hang my keys on the wall near my car. It was always basically in "ready to go mode" and my battery went dead (only 1 month old) I started keeping my key FOB in the other room. No issues so far. My BMW was the same way and I did have battery issues until I. And always click your FOB twice to lock and shut down peripherals.

 

[SCOPESYS]

.

They also suggested that I hit the lock button twice when I walk away to hear a beep and the car is supposed to go into a sleep mode soon to reduce parasitic drain.

Really -- not heard that one before.

I know some things keep running when you lock the car, but they tend to Go to Sleep, within a few minutes - at least that's what I saw a few months ago when I was monitoring the battery current, so get some idea how fast the battery should discharge, if the radio was on, but the engine was not running ... NOT VERY LONG - as many have experienced.

What also surprised me (alarmed me), was when the HONDA Battery was low, (about 1/2 estimated Charged capacity) putting it on charge with a decent Battery charger, it still would only charge at an unexpectedly low rate, even though it was down to about 1/2 charge capacity. Never seen a battery do this before, (that was not defective), which makes me start to believe that the Honda batteries are either sub-standard from day one, or some may have been damaged by deep discharge between factory and sale at the Dealership.

Will try some measurement soon with the "lock button twice" thing and see what happens to the current draw, !!...

Being stuck with a Flat battery is one of my major concerns with the Civic .. especially after all the battery issue reports in this forum.

 

[SCOPESYS]

They also suggested that I hit the lock button twice when I walk away to hear a beep and the car is supposed to go into a sleep mode soon to reduce parasitic drain.

I have to call that one yet another load of Dealer Total BS !!

If the car has been sitting, locked for more than a few minutes, the static current draw is about 0.3A -- which unfortunatly is HIGH !!!

IF the car is unlocked, the discharge goes up to about 2.5 A

If the car is locked, either by auto-lock, or hitting the lock button on the Fob once, or hitting it twice, the current draw DROPS down over about 1 minute back to the same 0.3A

2.5 --> 1.2 --> 0.7 ---> 0.3

I assume as various steps are different systems "Going to sleep"

==============

Very roughly, assume a 45AH CAPACITY Battery, 50% Discharged = 22.5 AH lost

= 22.5/0.3 Hours of drain @ 0.3A = 75 Hours = 3 days !!!!

OK, I must be wrong here ? HELP . No way the car will not start of sitting 3 days !! but even if the above is out by a factor of x10, thats only 1 Month before the Battery cannot start the car !!


===
If the car has the ACC on, Radio running, but everything else off (motor not running), the the Current draw playing music (Cars USB Mp3 player) is about 6A, and it hardly varies from MIn to Max volume.

22.5/6 = 3.75 hours of playing just te radio before battery may not start.

If Fan, or lights are on, then will be WAY WAY Less !!

===
Note: Static Current draw might be in error, because to see the Current measurement on the Clamp on Ammeter, I had to have the hood open, so that might be causing some anti-thief function to be drawing more current ?
Maybe next time I will figure out a way to do this with the Hood closed... phone videoing the meter under the close hood ?

 

[latole]

Not really, it’s a 12v system.

A 12 volts battery need close to 13.5 volts to charge

Look a battery issue here, old story with 10th generation Civic

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