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Crazy phantom battery drain ?

geoffdragon

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Location
south wales
Car
accord 2.2 ex
Hi all, 2005 Accord Cdti pre-facelift.
Problems began last September, when the car was left at the airport for 3 weeks. On return the battery was flat and a mate had to use jump leads to give me enough charge to start the car.
When we got home, I put a new Varta Blue 74A battery on it. Through the Winter the car has been used every 3 or 4 days and sometimes I felt that it may or may not start. I bought a smart charger to keep it topped up if left any longer.
Haven't used the car for the last 10 days and had an Mot booked today.
When I tried to start it - flat !!!! Managed to jump charge it off my wife's Passat - which will happily sit for a month without problems.
Over the Winter I did a load of tests on the electrics.
Battery volt drop test - OK
Current draw when locked and standing - 24ma with a flick to 46ma every 2 - 3 seconds, (in time with the alarm led).
I have a digital voltmeter plugged into the cigar lighter socket and that reads 14.2 to 14.4v when running.
The only electrical accessory fitted since I had the car is reverse sensors, but they only operate when in reverse gear with engine running.
The alternator was replaced by Honda two years ago.
When at the garage for the mot, I had a chat with one of the techs - he used to work as an auto-electrician, and having told him everything I have tested, he was as bemused as me, and said it wouldn't be worth me paying to have it tested as they would only repeat what I have already done.
The car doesn't have HFT fitted - I took the dash off to see.
I've searched all the forum sites but not found anything that may be my problem
If anyone has any ideas please reply as I'm getting frustrated at what is a lovely car.
I have got breakdown cover but really, a car with supposed Honda reliability should be able to start after a couple of weeks standing.
Best regards, Geoff
 
the alarm can drain the battery

if it's got a tailgate, some issues there are known to drain the battery
 
Hi and thanks.
No the car is a saloon and I've checked all the courtesy lights.
Given that there's 24ma standing drain, I would have thought thats the alarm/immobiliser.
Wonder if anyone knows the specific current that it should take.
The digital voltmeter shows around 0.2 - 0.3 volt drop a day when the car isn't used so I'm tearing my hair out ( not that there's much ) trying to work out why.
Going to get the battery tested again tomorrow just in case the lst test was wrong.
 
check it without then with the alarm set.

e.g. get your DMM visible with the bonnet closed, on current drain if possible, then

1. leave the boot up and use the keyfob to lock the car ....the alarm will not set with boot open (obviously switch off any lights in the boot)

2. then shut the boot ....the alarm should then set
 
Ok just tried that. DMM on long lead, bonnet shut, boot open, courtesy light disconnected.
Locked the car, the alarm didn't set.
Reading 150ma.
Closed boot, alarm set itself.
Reading 24ma.
Something can't be switching off until the alarm sets but still its only showing 24ma when locked and standing.
 
that's interesting, the extra current with boot open must be the MICU waiting for the boot to close

anyway, 24mA must be the alarm, which works out at only ~0.5 Ah per day

I'm not sure if it's possible to lock the car without the alarm set ....maybe try locking the doors from the button in the door (with driver's window down a bit) and see what current drain is then

AFAIK if you use the key in the door, it also sets the alarm same as using the keyfob, but I suspect that there is a way to alter that
 
Hi again.
Battery tested at local garage this morning, test showed battery OK but needs charging.
Thats not unexpected so its on charge now.
Measured the voltage loss and it's 0.26 volts in 24 hours.
No idea if 24ma drain would cause that but if it does then there's very little I can do about it.
I've looked everywhere but cant find any info about " lock and immobilise without the alarm".
 
have you checked the current when the doors are not locked, also with the doors locked from the master switch in the door (that doesn't set the alarm) ?


edit:
btw this problem is more usual in the 2.4 petrol car, as the Ah rating in that car is a lot smaller than the Ah rating in the diesel car
 
For the first check, I take it you mean with the doors closed, bonnet open, unlocked ?
Secondly, thats the lock switch by the window switches on the door armrest ?
Would I have to be in the car or could I do it through an open window ?
The battery is on charge at the moment so I'll try tose readings later on.
 
1. everything shut but unlocked (watch out, if the alarm is set and then you unset it, and merely open and close the door, the alarm sets itself, so make sure you put the key in the ignition and then take it out)

2. locked with master switch in armrest, either from inside the car, or set a long rod against the window that you can use with window open a tad
 
Hi, latest set of test figures.
Car standing, all closed up, not locked 28ma.
Locked with remote, after current from locks ended, 130ma for 15 seconds, then fell back to 23ma with alarm on.
Car open, wife in car, locked with master switch, no alarm 20ma.
Looks like the alarm system takes 3ma so maybe I need to hunt for the 20ma excess.
This is going to get awkward with the DMM at the front of the car, the car closed and locked with no alarm and tring to pull fuses from the fusebox under the steering wheel. LOL
 
IMO 20 or even 30 mA isn't going to drain a 75 Ah battery, but it is known that the alarm can drain the battery in the 2.4 car, if left for a couple of weeks [the 2.4 has a 45 Ah battery, original was Panasonic 46B24L(S)-MF]

Pulling fuses might be interesting, but a better exercise would be some kind of Ah meter i.e. something that totalises the Amps over Time. If there is anything else that drew current, that would show up. But I've only ever heard of (and got) an Ah meter for mains power.
 
OK, just pulled all the fuses and put the dmm across the socket pins.
The only fuse showing anything is fuse 6 under dash. Thats I believe all the courtesy lights in the car plus audio unit +. Whatever that means.
It shows 880ma but drops to 410ma when the drivers door courtesy switch is pressed off.
Not to confuse the issue, I dont think thats relavant, as I checked off the battery post, with fuse 6 in 23ma and with it out 22ma.
So it must control something thats on when the car is unlocked..
I agree totally that those sort of drain figures shouldn't drain the battery to the extent that it wont start the car.
Crazy but it's true.
 
Just a thought ....does the alarm sounder work ?

Maybe the alarm is being triggered and there's no sound.
 
Don't know about that - never heard it go off but havent seen the indicators flashing either, only when locking or unlocking car.
How would I go about setting it off ?
 
A little bit off topic I apologise. Why does the alarm go off if you open the door with the key? What if the battery in your fob failed?

Back on topic.
Don't the diesels have some sort of automatic heating coil when the temperature drops below a set point? Maybe that sensor is faulty and causing the heater to run?
 
Thanks for your suggestions.
The lock system worked as described in the handbook. I guess its another of those quirks that gets Honda dealers business.
As far as I know the only pre-heater system is the heaters that come on when the ignition is turned on prior to starting.
If anyone knows any different please speak up.
Seem this isn't a model specific problem many threads on the net about new Accords suffering, as well as Mercs and Lexus. One owner poined out he had spent 50 grand on a car that he can't leave at the airport when on holiday.
Thats my worry although fortunately mine wasn't in that price tag.
Would love to sort it out, if I can't then its the wife's Passat that will be going to Gatwick
When the charging finishes this evening (hope hope) I'll disconnect the battery and check the voltage in the morning before reconnecting.
No plans to use the car for a couple of days so I'll see how much drop in volts each morning.
 
Yes it's true, if the battery in your keyfob fails, even if you lock the car with the key, when you come back and open it with the key, the alarm goes off. I know that it doesn't mention this in the owners manual (lots of things aren't in the owners manual) .....but I suspect that this can be changed.

Diesel doesn't have any "diesel heater" (heater of diesel fuel)..... it has glow-plugs, and the aircon runs in reverse in cold weather (aka "diesel heater" = car heater on the diesel car).

As I say, it has been reported that the tailgate can get into a mode such that it drains the battery. Maybe a door lock can too ?

If you go to the airport in a 2.4 petrol and leave it parked for more than 2 weeks, best procedure is to lift the bonnet, lock everything with the keyfob, disconnect the -ve lead from the battery, and then close the bonnet. The alarm is not set but the battery will be ok when you come back (unlock drivers door with key, lift bonnet, put -ve lead back, use keyfob to open all doors, close bonnet).
 
Thats my read on the heater system.
Already thought about disconnecting battery at Gatwick, but, booked into hotel with parking and they valet park the car.
Unless I can persuade them to let me do it.
 
Treat yourself to a battery booster pack. Charge it up and leave it in your car ready for your return.
 
Had considered that but it would need to be a big one and I had read that they only hold charge for a few days.
 
How are you testing the current draw? Are you disconnecting the battery and bridging the leads with your multimeter?

If you are using an amp clamp they can be very handy however not always very accurate with such low current draw.

Personally I think spiking regularly at 0.4 amps is way too high.

Remember that the car will need to allow the bus networks to go to sleep before getting an accurate resting current draw rate.
I can't speak for Honda as I've never tested current draw on one, but many other manufacturers bus networks sleep after 16, 30 or 60 minutes.

I would start again from scratch if I were you as it sounds as if you may be over complicating what could be a fairly simple diagnosis.

Start with fitting your multimeter on amps between the negative terminal and a GOOD body earth with the cars negative lead disconnected.

1, lock the car up as normal and check the reading every 10 - 15 mins for 2 hours. Record your results
2, lock the car using the central locking button on the drivers door (disables the alarm). check the reading every 10 - 15 mins for 2 hours. Record your results

If this doesn't provide a satisfactory result I would encourage you to invest in a fuse bridger and test each fuse when the car is locked and in sleep mode.

Hope this helps
 
You will find that this will help a lot if you get to the testing fuses stage.

http://pages.ebay.com/link/?nav=item.view&alt=web&id=251312009110

Also, don't forget that the multimeter will have a 10amp fuse in it so don't exceed this or you'll be out of action until you can find a replacement. I normally hold of the negative lead on to the negative terminal whilst locking the car to prevent any damage to my multimeter, then when the car is fully locked I will disconnect the lead keeping my multimeter attached to the lead and terminal at all times to prevent any radio locking or other issues.
 
Hi, and thanks for the input. Amps drain is being tested with the meter between the battery post and the disconnected earth lead. I'm using an AVO ****ogue meter as thats the only one I have that will directly switch between amps and milliamps without disconnecting the meter wires
The current spike is 40 milliamps not 400. (0.040A)
I will try leaving the meter connected and check readings at 15 min intervals.
With the car open ( thats the only way I could get at the underdash fusebox) I pulled all the fuses and checked for current across any, the only one was the fuse controlling interior lights and audio + if that makes sense. Left that fuse out and rechecked the draw but it was still 24ma.
I'll have a look at that ebay item, would be handy in any case.
Honda give a maximum draw of 30ma so as far as they would be concerned the car is in spec.
May just get an 80ah battery and keep the existing one float charged as a battery booster.
The existing ( 6 month old 74Ah battery has been tested and is fine)
Thanks agin, Geoff
 
ok, sorry I was scan reading the post. If it is spiking at 0.04 amps then I'd be happy with that. Do you keep your car on the road or driveway?

If it is on a driveway I would just invest in a battery conditioner and keep that connected if you know the car will not be used for a few days.

This will solve your problems unless you are away from a power point (like at airport parking or street parking).

http://www.ebay.co.uk/itm/CTEK-Multi-MXS-5-0-12V-Car-Battery-Smart-Trickle-Charger-Conditioner-NEW-MODEL-/160927753460?pt=LH_DefaultDomain_3&hash=item25780aa4f4

Don't know which size would be best for your car but it probably says somewhere in the listing.
 
Yes it doesn't seem a lot, but I've just checked and the battery voltage now reading 12.73v, and has dropped 0.14 volts in 24 hours.
If it continues to drop at that rate I recon that it will get to 11.7 volts in around 5 days. Thats crazy.
I'll keep checking that figure. Also disconnect it and stick the ammeter on it to check for a few hours.
The car is on the road so trickle charging isnt a real option although I have a smart charger.
It's managable at home, using the car every few days, but, when we go on hols and the car is valet parked at an aiport hotel, it will cause a problem.
I dont know if the fuses are classed as "mini" or some other exotic name ?
Hey ho, Geoff
 
Normally referred to as a blade fuse or mini blade fuse.


I think you may be over ****ysing the battery fault. I've never heard of anyone checking the drop in volts over a period of time.
The battery is made up of 6, 2 volt cells. If the battery is faulty usually you'd drop one or two of these cells and the voltage would read anywhere between 4 and 10 volts. At that point its time for a battery. This isn't the case in yours.

The voltage of a battery will drop off after its been sitting there for a while, however it will keep its charge as the volts only supply the 'pressure' of the electricity, not the power behind it.

You may have heard of the term volt drop, this is a totally different thing and is basically a way of checking the condition of a wire.
 
^ IMO he's doing it all correctly

He says that the problems began in September when he left it at the airport for 3 weeks. This has happened to me too, but the battery in my car (2.4) is only 45 Ah (diesel is 75 Ah).

So he put a new 74 Ah battery in it. Then recently, he left the car for 10 days, and it was flat again.

He has had the battery tested. It could well be the battery, there was another thread some time ago, very similar (diesel too), where they eventually took the battery back and got it changed, and the problem stopped (there was no indication of the battery being faulty).

But, IMO, he is doing his best to see why the battery volts are dropping .....if you draw say 0.5 Amps from a 75 Ah car battery (I know it isn't 0.5 Amps, but bear with me), then that is 12 Ah per day, so I would expect to see the volts drop on a graph against time. Then disconnect the drain, the volts will rise a bit, but not back up to full voltage (depending on how many Ah had been drawn out)..
 
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