geoffdragon
Members
Ok freddofrog. It's raining here now so under the car ain't an option. Typing on phone so sorry about mistooks. Lol
Crazy phantom battery drain ?
- Thread starter geoffdragon
- Start date
freddofrog
won 16.4k on Euro lottery :)
Put it in a polythene bag ?geoffdragon said:
geoffdragon
Members
More worried about me. Lol. Supposed to be dry tomorrow or Monday. Have to find some long wires anyway.
SayamaAccord
And still...
False as in incomplete?geoffdragon said:
freddofrog
won 16.4k on Euro lottery :)
correct ....it's a single "spot" reading which doesn't really do much ......which is why I suggested buying an A-h meter in the beginningCliffordski said:
freddofrog
won 16.4k on Euro lottery :)
as well as A-h meters and polythene bags, there is a much older invention available called a "coat" :lol:geoffdragon said:
geoffdragon
Members
Just hope thes ah meter is reading ok. Must be - that's why the battery is going flat. Lol
geoffdragon
Members
Just checked the meter with a 21w and 5w bulb. Very close to rated wattages. Just for peace of mind.
geoffdragon
Members
In my search, I came across this article.
Text from a US service news bulletin
This is for the Accord (Acura in the US) and is aimed at dealers, but may be useful:
When it comes to parasitic draw, the body controller area network (B-CAN) system—first introduced in the ’04 TSX—is a major contributor. With the ignition switch turned to LOCK (0), all B-CAN-related components still receive battery power. This gives the various control units such as the gauge control module, the multiplex integrated control unit (MICU), the door multiplex control unit, the climate control unit, the power seat control unit, etc., a means of communicating when, for instance, a power door lock switch input signal changes or there’s a signal received from a keyless remote transmitter. Knowing what the B-CAN system does when you turn the ignition switch to LOCK (0) will help you to recognize if it’s causing an excessive parasitic draw problem. Normal parasitic draw on a battery varies from model to model, depending on the number of control units involved. Just remember if the draw is less than 50 mA, it’s normal; if it’s 50 mA or more, it’s excessive.
Wake-up Mode and Sleep Mode
The B-CAN system has two operating modes to reduce parasitic draw: the wake-up mode and the sleep mode. With the ignition switch turned to ON (II), the system is in the wake-up mode. During this time, the system has both +B power (HOT AT ALL TIMES) and IG1 power (HOT WITH IGNITION SWITCH ON) and there’s a parasitic draw on the battery of about 200 mA or more. When you turn the ignition switch to LOCK (0), the system stays awake as long as the key-off timer (part of the MICU) is running. The key-off timer shuts off when the B-CAN system receives a door switch open input signal; otherwise, it shuts off right at 10 minutes. With the system now in the sleep mode, the parasitic draw on the battery drops to less than 50 mA. It still has +B power (HOT AT ALL TIMES), though, and there are a number of signal inputs that can wake it up to do some work. A good example is the power door lock switch. When you push the switch to its lock or unlock position, the system wakes up, does whatever it needs to do, and then goes back to sleep 5 seconds later.
Don’t Just Rely on Component Replacement
Many service techs replace B-CAN-related components because they think those components are causing the excessive parasitic draw. When checking for excessive draw, they find that by pulling the backup fuse to the MICU, the parasitic draw drops to normal. What they don’t realize, though, is that the real cause for the B-CAN system staying awake could be a stuck door lock switch. If that door lock switch sticks in either its lock or unlock position (the input signal stays on), the system won’t return to the sleep mode. This will keep an excessive parasitic draw on the battery that will kill it in short order. Just how long that actually takes depends on the battery’s state of charge and other variables. A parasitic draw of about 200 mA will usually kill a battery in about 2 days. So the bottom line is this: When it comes to excessive parasitic draw, you can’t rely on component replacement to always fix things. Even though the suspected component was replaced, there’s still an excessive parasitic draw problem that will probably wind up in a comeback . . . not to mention one very unhappy service client.
Narrowing Things Down
An easy way to find out if the B-CAN system is staying awake—and causing an excessive parasitic draw problem—is to momentarily short one B-CAN communication wire to ground. There are two types of B-CAN systems: a slower (33.33 kbps) single-wire system, and a faster (125 kbps) two-wire system, which was first introduced in the ’09 TSX. Shorting the single wire to ground (single-wire system) or the CAN_H wire to ground (two-wire system) at any of the B-CAN-related components stops all B-CAN communication and puts all of the control units into the sleep mode. If doing this gets rid of the excessive parasitic draw, then an input signal to one of the control units or a control unit itself is keeping the system awake.
Finding the Culprit
There are two ways to find out which control unit is keeping the B-CAN system awake. One way is to use the All Data List in the HDS to check for any abnormal switch inputs such as a door lock switch that stays on. Such inputs will keep the system awake. The other way is to start unplugging the components on the B-CAN circuit one at a time. When you unplug the suspected control unit, the rest of the B-CAN-related components will fall sleep. Make sure there are no abnormal switch inputs to that control unit, though, such as a door lock switch that stays on, otherwise the B-CAN system will stay awake.
Some Handy Tips
Without a doubt, chasing down an excessive parasitic draw problem can be time-consuming, even frustrating work. Here are some handy tips to help make that job go just a little easier:
Text from a US service news bulletin
This is for the Accord (Acura in the US) and is aimed at dealers, but may be useful:
When it comes to parasitic draw, the body controller area network (B-CAN) system—first introduced in the ’04 TSX—is a major contributor. With the ignition switch turned to LOCK (0), all B-CAN-related components still receive battery power. This gives the various control units such as the gauge control module, the multiplex integrated control unit (MICU), the door multiplex control unit, the climate control unit, the power seat control unit, etc., a means of communicating when, for instance, a power door lock switch input signal changes or there’s a signal received from a keyless remote transmitter. Knowing what the B-CAN system does when you turn the ignition switch to LOCK (0) will help you to recognize if it’s causing an excessive parasitic draw problem. Normal parasitic draw on a battery varies from model to model, depending on the number of control units involved. Just remember if the draw is less than 50 mA, it’s normal; if it’s 50 mA or more, it’s excessive.
Wake-up Mode and Sleep Mode
The B-CAN system has two operating modes to reduce parasitic draw: the wake-up mode and the sleep mode. With the ignition switch turned to ON (II), the system is in the wake-up mode. During this time, the system has both +B power (HOT AT ALL TIMES) and IG1 power (HOT WITH IGNITION SWITCH ON) and there’s a parasitic draw on the battery of about 200 mA or more. When you turn the ignition switch to LOCK (0), the system stays awake as long as the key-off timer (part of the MICU) is running. The key-off timer shuts off when the B-CAN system receives a door switch open input signal; otherwise, it shuts off right at 10 minutes. With the system now in the sleep mode, the parasitic draw on the battery drops to less than 50 mA. It still has +B power (HOT AT ALL TIMES), though, and there are a number of signal inputs that can wake it up to do some work. A good example is the power door lock switch. When you push the switch to its lock or unlock position, the system wakes up, does whatever it needs to do, and then goes back to sleep 5 seconds later.
Don’t Just Rely on Component Replacement
Many service techs replace B-CAN-related components because they think those components are causing the excessive parasitic draw. When checking for excessive draw, they find that by pulling the backup fuse to the MICU, the parasitic draw drops to normal. What they don’t realize, though, is that the real cause for the B-CAN system staying awake could be a stuck door lock switch. If that door lock switch sticks in either its lock or unlock position (the input signal stays on), the system won’t return to the sleep mode. This will keep an excessive parasitic draw on the battery that will kill it in short order. Just how long that actually takes depends on the battery’s state of charge and other variables. A parasitic draw of about 200 mA will usually kill a battery in about 2 days. So the bottom line is this: When it comes to excessive parasitic draw, you can’t rely on component replacement to always fix things. Even though the suspected component was replaced, there’s still an excessive parasitic draw problem that will probably wind up in a comeback . . . not to mention one very unhappy service client.
Narrowing Things Down
An easy way to find out if the B-CAN system is staying awake—and causing an excessive parasitic draw problem—is to momentarily short one B-CAN communication wire to ground. There are two types of B-CAN systems: a slower (33.33 kbps) single-wire system, and a faster (125 kbps) two-wire system, which was first introduced in the ’09 TSX. Shorting the single wire to ground (single-wire system) or the CAN_H wire to ground (two-wire system) at any of the B-CAN-related components stops all B-CAN communication and puts all of the control units into the sleep mode. If doing this gets rid of the excessive parasitic draw, then an input signal to one of the control units or a control unit itself is keeping the system awake.
Finding the Culprit
There are two ways to find out which control unit is keeping the B-CAN system awake. One way is to use the All Data List in the HDS to check for any abnormal switch inputs such as a door lock switch that stays on. Such inputs will keep the system awake. The other way is to start unplugging the components on the B-CAN circuit one at a time. When you unplug the suspected control unit, the rest of the B-CAN-related components will fall sleep. Make sure there are no abnormal switch inputs to that control unit, though, such as a door lock switch that stays on, otherwise the B-CAN system will stay awake.
Some Handy Tips
Without a doubt, chasing down an excessive parasitic draw problem can be time-consuming, even frustrating work. Here are some handy tips to help make that job go just a little easier:
- Use the Auto Battery/Electrical System ****yzer (ED-18) to make sure the vehicle’s battery and charging system are OK.
- Check to see if the vehicle has any aftermarket accessories. If it does, let the service consultant know right away. He or she will need to get permission from your client before you can unplug or remove those accessories.
- If the vehicle has a security system, make sure you unplug the hood switch to simulate a closed hood.
- To check for excessive parasitic draw, use the LH41A AC/DC Low Current Clamp Meter (Model No. FLULH41A), a required special tool. Only clamp meters that match the LH41A’s resolution and accuracy specs can be used to measure parasitic draw. See Meet the LH41A Clamp Meter! below for details.
- Check the vehicle under the same conditions reported by your client or written on the RO (for example, your client reported all the doors were locked and the security system was turned on).
- After turning the ignition switch to LOCK (0), open and close the driver’s door to shut off the key-off timer. On most vehicles, this will cut the time it takes for the B-CAN system to go into the sleep mode.
SayamaAccord
And still...
Your call but personally I would pay Honda a few quid to report on the All Data List.
geoffdragon
Members
Heading in that direction. At the moment my air con and audio aren't working. As well as display for clock ant temperatures. Just picked up some spare fuses so hopefully that's all.
geoffdragon
Members
Problem solved. Must be getting lucky 2 blown fuses in the first 4 I checked. LOL
Halfrauds only place open - over £6 for 9 ***orted fuses.
Just bought 80 for £4 on the bay.
Teach me to keep some spares..
Halfrauds only place open - over £6 for 9 ***orted fuses.
Just bought 80 for £4 on the bay.
Teach me to keep some spares..
freddofrog
won 16.4k on Euro lottery :)
Crikeygeoffdragon said:
IMO that service bulletin in #159 doesn't really help. For example it mentions "unplug the hood switch to simulate a closed hood", but I've just had a look and the plug is buried down on the right-hand-side of the bonnet catch/release mechanism. Other things are just plain obvious, but none of it takes account of an intermittent fault .....and if you go to a dealer for them to plug in their HDS, you probably won't get much change from £100 with nothing found.
That's why I seriously recommend taking hourly readings as in #142.
If you want to keep the meter where it is, I have found that instead of unplugging "the hood switch to simulate a closed hood", it's simpler (though it's not easy) to just force the catch down to simulate a closed hood (bonnet). Then the car can be fully locked with the A-h meter in place on the battery. Obviously the bonnet will not close fully like that, so if the car is parked on-street then you might want to unbolt the catch/release mechanism and lower it. You'd have to remove upper trim on the grill to get better access (making sure you know which clip goes in which hole as some are different lengths) and then you could "unplug the hood switch".
edit: reason for over-riding or even lowering the catch/release mechanism is so that you can just lift up the bonnet without unlocking the car.
freddofrog
won 16.4k on Euro lottery :)
btw after 45 hours with bonnet shut,. my car had only used 0.471 Ah
geoffdragon
Members
Hi there. I know about the bonnet lock trick. Need a strong screwdriver to lever it over. Think I'll put the meter on it for the day tomorrow but if there's no luck will have a chat with honda on Tuesday. I came across a honda instruction sheet for using hds to query micu and there are so many interconnected controllers I think the only way is to plug into it. There is a way to get any codes displayed on the mileometer but decoding any meaningful info is not easy. As well as info about anything not going to sleep It will also tell when things switch on and off. I think after nearly a fortnight I have tried everything I can. Not happy about it but frustrated now.
freddofrog
won 16.4k on Euro lottery :)
doesn't work with a long one, you need a very short one which is just the right lengthgeoffdragon said:
geoffdragon said:
I know, I wrote this ....
freddofrog said:
I have an HDS, on 7th gen it does not plug directly into the bus system
It plugs into the OBD port which connects to the "gauge control module". That module acts as a gateway.
I have "played" with the HDS on my car and tbh it won't help in this particular problem because something is coming on intermittently and if there are no codes then no-one will find out what is coming on ....because the entire CANbus has to be powered up for the HDS to work !! (Cacth 22)
The only way you will solve this is to read the A-h meter on a regular basis over many hours without unlocking the car. That way you will see if the intermittent fault is regularly intermittent, or if it's an additional current drain that comes on later and stays on.
freddofrog
won 16.4k on Euro lottery :)
Got some pics if they help
screwdriver is an ancient stubby thing that goes in the handle either way round, you can see how short it is, resting on the A-h meter
here is is with the trim above the grill removed (catch in the closed position)
and finally with the trim in place (catch in the closed position again)
As I say, the alarn can be fully set like this, but the bonnet will not close fully. But if you remove the trim above the grill you'll see that it should be possible to easily drop and unplug the catch/release so that the bonnet can be closed completely with alarm set
screwdriver is an ancient stubby thing that goes in the handle either way round, you can see how short it is, resting on the A-h meter
here is is with the trim above the grill removed (catch in the closed position)
and finally with the trim in place (catch in the closed position again)
As I say, the alarn can be fully set like this, but the bonnet will not close fully. But if you remove the trim above the grill you'll see that it should be possible to easily drop and unplug the catch/release so that the bonnet can be closed completely with alarm set
geoffdragon
Members
Home all day Monday. And it's a fine forecast, so will throw the latch and leave bonnet open. Will take readings through the day and see if anything shows up. Ta for the info about hds.
geoffdragon
Members
Started monitoring. Tried mm first an showed 22.5ma. Connected wattmeter and the amps are fluctuating between 0.02 and 0.15. I wonder if yours is steady freddofrog. Also when I first connected up one of the relays - I think in the small box was clicking quickly for about 10 seconds. Couldn't get to it quickly enough to see which one. Will keep watching today but it looks like this mystery drain is always on but the dmm can't see it.
freddofrog
won 16.4k on Euro lottery :)
The amps reading on mine actually drops to 0.00 after about 20 seconds, and seems to stay at 0.00
But the Ah totaliser does increase hour by hour, so there is either a small drain below 0.00 that is totalising (probably the alarm) and/or something else coming on occasionally but only using a small amount.
You said in #161 that the aircon, audio, and display for clock/temperatures.are not working, if they've always been like that, then one of those could be the source of the drain ? i.e. a module for one of those might be struggling to power up
The image below shows all the modules on the B-CAN side of the bus system but I suspect that there may also be a couple more.
But the Ah totaliser does increase hour by hour, so there is either a small drain below 0.00 that is totalising (probably the alarm) and/or something else coming on occasionally but only using a small amount.
You said in #161 that the aircon, audio, and display for clock/temperatures.are not working, if they've always been like that, then one of those could be the source of the drain ? i.e. a module for one of those might be struggling to power up
The image below shows all the modules on the B-CAN side of the bus system but I suspect that there may also be a couple more.
geoffdragon
Members
Hi there, no everything has always worked. Must have blown a couple of fuses messing about.
Still monitoring, though it looks like a constant drain - the hourly differences are all pretty much the same since 8.30 this morning.
Strange how the Amp and Watt displays are jumping around. I guess my cheap mm is only sampling once.
Will post results later.
Thanks for diagram, and your patience.
Still monitoring, though it looks like a constant drain - the hourly differences are all pretty much the same since 8.30 this morning.
Strange how the Amp and Watt displays are jumping around. I guess my cheap mm is only sampling once.
Will post results later.
Thanks for diagram, and your patience.
geoffdragon
Members
Before I connected watt meter, I Took readings with the multimeter.
Car closed up but unlocked 27.5ma
When first locked up 150ma
After waiting for systems to shut down 22.5, but the needle was "quivering" as though there were changes taking place.
Hourly readings taken off Watt meter ( connected the same way as your Brian )
Time Amps Ah Hrly Diff Wh Hrly Diff
08.30 0.02 - 0.15 0.075 0.8
09.30 0.02 - 0.16 0.219 0.144 2.5 1.7
10.30 0.05 – 0.17 0.360 0.141 4.2 1.7
11.30 0.04 – 0.18 0.497 0.137 5.8 1.6
12.30 0.05 – 0.15 0.632 0.135 7.4 1.6
13.30 0.04 – 0.14 0.771 0.139 9.0 1.6
14.30 0.05 – 0.20 0.910 0.139 10.6 1.6
15.30 0.03 – 0.16 1.049 0.139 12.3 1.7
16.30 0.05 – 0.16 1.186 0.137 13.9 1.6
Looks as though there is a consistant hourly drain from the word go, although the fluctuating Amp readings are confusing.
Maybe a decent DMM would pick up those changes.
I have no idea how to look for the fluctuating but constant drain now as pulling fuses under the dash with the car closed and alarmed would seem impossible.
Car closed up but unlocked 27.5ma
When first locked up 150ma
After waiting for systems to shut down 22.5, but the needle was "quivering" as though there were changes taking place.
Hourly readings taken off Watt meter ( connected the same way as your Brian )
Time Amps Ah Hrly Diff Wh Hrly Diff
08.30 0.02 - 0.15 0.075 0.8
09.30 0.02 - 0.16 0.219 0.144 2.5 1.7
10.30 0.05 – 0.17 0.360 0.141 4.2 1.7
11.30 0.04 – 0.18 0.497 0.137 5.8 1.6
12.30 0.05 – 0.15 0.632 0.135 7.4 1.6
13.30 0.04 – 0.14 0.771 0.139 9.0 1.6
14.30 0.05 – 0.20 0.910 0.139 10.6 1.6
15.30 0.03 – 0.16 1.049 0.139 12.3 1.7
16.30 0.05 – 0.16 1.186 0.137 13.9 1.6
Looks as though there is a consistant hourly drain from the word go, although the fluctuating Amp readings are confusing.
Maybe a decent DMM would pick up those changes.
I have no idea how to look for the fluctuating but constant drain now as pulling fuses under the dash with the car closed and alarmed would seem impossible.
freddofrog
won 16.4k on Euro lottery :)
Yes there's going to be a problem finding that, and IMO it's not going to be found with an HDS. Maybe go and ask to speak to a dealer's technician, explain the situation, those results, and ask if he agrees that an HDS will not find it (because the car will be powered up with HDS plugged in).
By the way, when you say DMM, note that DMM = Digital Multi Meter, but you say "the needle was quivering" , which implies that it's an ****ogue multi meter, and one of those will not show up rapid fluctuations due to inertia in the coil that moves the needle. Having said that, if the hourly Ah = ~ 0.14 Ah and the meter flips to a current of ~0.14 Amps, then I would have expected an ****ogue meter to display 0.14 Amps (since that seems to be the dominant current).
I have also found this manual on the Watt meter
http://www.batteryspace.com/ProductImages/watt-up/wu100v2_user_manual_batteryspace.pdf
which is a slightly better pdf, because it has the sample rate ..... 1000 samples per second. The Watt meter uses a DSP to work out what is happening, probably samples Volts and Amps, then works out Watt-seconds (Joules) and then uses Watt-seconds and the Volts and Amps, to update the Amps and Wh and Ah in the display.
IMO a true DMM will not give your more useful info than the Watt meter is providing, the only thing that would give a tad more info would be a storage oscilloscope, but IMO you now have all the info that you can get.
Some brain-storming is now needed
My try ....possibly a loose connection on a door switch ....set the alarm with a window down a small amount, wait a few minutes, then stick your hand in to see if the alarm goes off. Or sit still in the car and set the alarm and stay still for a few minutes and then start moving about and/or try to open a door.
By the way, when you say DMM, note that DMM = Digital Multi Meter, but you say "the needle was quivering" , which implies that it's an ****ogue multi meter, and one of those will not show up rapid fluctuations due to inertia in the coil that moves the needle. Having said that, if the hourly Ah = ~ 0.14 Ah and the meter flips to a current of ~0.14 Amps, then I would have expected an ****ogue meter to display 0.14 Amps (since that seems to be the dominant current).
I have also found this manual on the Watt meter
http://www.batteryspace.com/ProductImages/watt-up/wu100v2_user_manual_batteryspace.pdf
which is a slightly better pdf, because it has the sample rate ..... 1000 samples per second. The Watt meter uses a DSP to work out what is happening, probably samples Volts and Amps, then works out Watt-seconds (Joules) and then uses Watt-seconds and the Volts and Amps, to update the Amps and Wh and Ah in the display.
IMO a true DMM will not give your more useful info than the Watt meter is providing, the only thing that would give a tad more info would be a storage oscilloscope, but IMO you now have all the info that you can get.
Some brain-storming is now needed
My try ....possibly a loose connection on a door switch ....set the alarm with a window down a small amount, wait a few minutes, then stick your hand in to see if the alarm goes off. Or sit still in the car and set the alarm and stay still for a few minutes and then start moving about and/or try to open a door.
geoffdragon
Members
Hi. Yes I know dmm is digital but my dmm keeps blowing the 200ma fuse. Have to set it on 20a but then when the cable is moved to the ma socket the surge blows the fuse so I use a old ****ogue avo that only uses one socket for all the scales. Hence the quivering needle. I wondered if a higher quality dmm would see the fluctuations. I have an old oscilloscope but only reads volts nothing fancy. Anyway I think I have enough info now to talk to a honda tech and ask if they can find the problem using their system. Will write all my notes up in one place and try tomorrow.
If it was a dodgy door switch, surely the alarm wouldn't set ?
I have stuck my hand into an open window and the alarm went off.
Have also opened with the key and set it off.
If it was a dodgy door switch, surely the alarm wouldn't set ?
I have stuck my hand into an open window and the alarm went off.
Have also opened with the key and set it off.
freddofrog
won 16.4k on Euro lottery :)
To use the digital multi meter, put the avo or a jump cable across to start with, then put the DMM in parallel, then remove the avo/jump-cable.
To use an oscilloscope, put the avo in as you have done, then use the oscilloscope to measure volts across the avo. You should then see the waveform, and make a sort of calibration of mV to mA from what you saw on the DMM or the Watt meter.
Yeah you would expect that alarm would go off if there was a dodgy door switch, but the first rule of trouble-shooting is not to use expectations to rule out a fault. Hence the check with hand in window. Also, unlocking with key is not the same sort of test.
If I were you I'd get everything else working properly as well. And if you do take it to a dealer, from my own experience of Honda dealers they'll probably see you as a source of "stupid" money, so be careful. They won't want you talking to their technician(s) for long either (if you can get to them)
To use an oscilloscope, put the avo in as you have done, then use the oscilloscope to measure volts across the avo. You should then see the waveform, and make a sort of calibration of mV to mA from what you saw on the DMM or the Watt meter.
Yeah you would expect that alarm would go off if there was a dodgy door switch, but the first rule of trouble-shooting is not to use expectations to rule out a fault. Hence the check with hand in window. Also, unlocking with key is not the same sort of test.
If I were you I'd get everything else working properly as well. And if you do take it to a dealer, from my own experience of Honda dealers they'll probably see you as a source of "stupid" money, so be careful. They won't want you talking to their technician(s) for long either (if you can get to them)
geoffdragon
Members
Thanks for that info. Will keep that in mind in case this goes on. Will try to speak to someone tomorrow but will need to be convinced that they can find the problem before it goes in. I know the prices of parts via honda have seen the obscene prices of some of these control units. I recon if you wanted to build an accord from parts you would be looking at 6 figures. Hey the cars only worth c 3k at best so I ain't going to spend a grand sorting it out. Lol
freddofrog
won 16.4k on Euro lottery :)
There is a small possibility that an HDS would show a fault with one of the modules on the B-CAN, it could be any one of them. A good example of a weird fault is this thread http://typeaccord.co.uk/forum/topic/19578-dtc-codes-help/
But If you decide to investigate a bit further yourself, if the needle on the Avo was "quivering" then that means that the current is fluctuating rapidly. It might be worth using an oscilloscope, it doesn't matter how old, you can take a picture of the waveform.
The in-circuit resistance of the Watt-meter is 0.001 Ohms, so 24 mA would show as 24 uV (micro-volts) across the two black leads of the Watt-meter. If you wanted to make the voltage higher on the scope, you could try making a 1 Ohm resistance with some long thin wire. You'd put that in place of the black Watt-meter leads and use the scope to measure the volts across the wire. 24mA would now be 24mV on the scope. If the waveform is rapidly changing then there really is something weird.
But I can definitely confirm that on at least one occasion of leaving my car locked for 4 weeks with a decent battery, it went totally flat. But my Watt-meter is not showing enough drain, so if there was something that caused the battery to go flat in my car, whatever it was, it seems to have fixed itself
But If you decide to investigate a bit further yourself, if the needle on the Avo was "quivering" then that means that the current is fluctuating rapidly. It might be worth using an oscilloscope, it doesn't matter how old, you can take a picture of the waveform.
The in-circuit resistance of the Watt-meter is 0.001 Ohms, so 24 mA would show as 24 uV (micro-volts) across the two black leads of the Watt-meter. If you wanted to make the voltage higher on the scope, you could try making a 1 Ohm resistance with some long thin wire. You'd put that in place of the black Watt-meter leads and use the scope to measure the volts across the wire. 24mA would now be 24mV on the scope. If the waveform is rapidly changing then there really is something weird.
But I can definitely confirm that on at least one occasion of leaving my car locked for 4 weeks with a decent battery, it went totally flat. But my Watt-meter is not showing enough drain, so if there was something that caused the battery to go flat in my car, whatever it was, it seems to have fixed itself
freddofrog
won 16.4k on Euro lottery :)
One more thing, on the Honda e-manual/DVD there are loads of tests for each module, some of which go into details on testing the connectors and voltages. It is possible that one of the modules has developed a resistance to ground, or something similar, which does not show up as a fault until you want the ssytem to power down. That is why it's best to make sure that everything on the car is working properly.
freddofrog
won 16.4k on Euro lottery :)
Update on the readings from my Watt-meter .....
Since I also started doing the bonnet over-ride trick and have been lifting the bonnet to read the Watt-meter with the alarm set, the number of A-h used has become (based on more than 24 hours) about 9 mAh per hour, which indicates a constant 9 mA of current.
So even your minimum of 24 mA looks too big, and I can now categorically say on this forum that a locked and alarmed 7th gen should not run the battery flat when left for a few weeks .....because even the 45 Ah battery in the 2.4 would take more than 4,500 hours (or 6 months) to run flat at a drain of 9 mA.
Since I also started doing the bonnet over-ride trick and have been lifting the bonnet to read the Watt-meter with the alarm set, the number of A-h used has become (based on more than 24 hours) about 9 mAh per hour, which indicates a constant 9 mA of current.
So even your minimum of 24 mA looks too big, and I can now categorically say on this forum that a locked and alarmed 7th gen should not run the battery flat when left for a few weeks .....because even the 45 Ah battery in the 2.4 would take more than 4,500 hours (or 6 months) to run flat at a drain of 9 mA.
geoffdragon
Members
Its good to hear someone is happy LOL.
That drain does look low. Don't know whats on your car but mine has all the toys. Maybe thats why drain is higher. who knows.
Going to chat with Honda shortly, will come back when I know more.
That drain does look low. Don't know whats on your car but mine has all the toys. Maybe thats why drain is higher. who knows.
Going to chat with Honda shortly, will come back when I know more.