Battery drain... is it the BCU or LSM?

[SD1too]

OK, my ammeter has been in circuit for over an hour and a half now and this is what is happening.

The reading is 0.03 amps with a brief change for a second or two to 0.02 amps. This pattern repeats once or twice per minute and suggests that the current is close to 0.030 amps. That equates to 30 mA which matches MG Rover figures. However, there's an oddity!

The reading also increases to a steady 0.09 amps (90 mA) for anything from a few seconds to a whole minute. It then returns to 0.03 amps. It's an instantaneous change. Do I have a fault too?

So we're still no further forward! We need a third car to settle the question of this intermittent jump to a higher current. Any volunteers?

Simon

[Supervinnie40]

I myself also waited for at least an hour and made 1 video of the drain with the wiper motor connected:

I should add that the car was not locked while doing this test.

https://www.youtube.com/watch?v=YWkGdxI7EVM
It jumpst up and down from 0.00 to 0.07

After I pulled the plug:
https://www.youtube.com/watch?v=AvWG8WHmB4I
Still jumps, but less high. It won't go past 0.03.

[SD1too]

My quiescent current never falls to zero as yours does.

With my car centrally locked and alarmed the current is:

1. About 2 A for a minute or two.
2. 0.1 A (100mA) for 14 minutes.
3. Thereafter 0.03 - 0.04 A (30 - 40 mA) with excursions to 0.1 A (100 mA).

I also removed my wiper motor connector and the excursions decrease to 0.06 A (60 mA). When I reconnect the wiper motor the system "wakes up". Perhaps this is because a connection (the brown/green) has been removed from the BCU then re-established.

Your earlier photos of the wiper motor and its connector appear to be reversed. Please can you check the wiring colours because on my car black is definitely on pin 4 which corresponds to RAVE.

In your first video above Vinney, rotating the selector from the 10A to the 200mA range without moving the probe connection is invalid. You'll notice that the decimal point in the display moves only one place whereas it should move by three places (amps to milliamps). You should leave the meter on the 10A range.

Simon

[colintf]

Originally Posted by Supervinnie40

That would be about 114km (about 71 miles). Have to admit, I've never heard of them before?


Thanks for your effort Simon.
Mine does a very similar thing as yours does (apart from the sat nav thing). And mine stays at 0.07. If I wait long enough (about an hour), it goes down a lot (0.01) but jumps up and down all the time. It can go from 0.01 to 0.1 and back to 0.01 within a second. It's not always up to 0.1, it seems to give total random numbers.
I'll make a video of both situations and put it on Youtube. Maybe that'll help.

They are well known in MG circles, particularly MGB and earlier, but do all MG's. I know them well, they come over to the uk a few times a year, and I see them overseas a few times. They've converted a classic to an electric car as well, so they know electrics. Give them a call and ask for Cat or Thjys, say I (Colin Murrell) suggested you call them) they may offer to help or point you in the right direction


https://www.mgworkshop.nl/en

[Supervinnie40]

Originally Posted by SD1too

My quiescent current never falls to zero as yours does.

With my car centrally locked and alarmed the current is:

1. About 2 A for a minute or two.
2. 0.1 A (100mA) for 14 minutes.
3. Thereafter 0.03 - 0.04 A (30 - 40 mA) with excursions to 0.1 A (100 mA).

I also removed my wiper motor connector and the excursions decrease to 0.06 A (60 mA). When I reconnect the wiper motor the system "wakes up". Perhaps this is because a connection (the brown/green) has been removed from the BCU then re-established.

Your earlier photos of the wiper motor and its connector appear to be reversed. Please can you check the wiring colours because on my car black is definitely on pin 4 which corresponds to RAVE.

In your first video above Vinney, rotating the selector from the 10A to the 200mA range without moving the probe connection is invalid. You'll notice that the decimal point in the display moves only one place whereas it should move by three places (amps to milliamps). You should leave the meter on the 10A range.

Simon

Seems the confusion keeps continueing . However, you locked your car. I didn't. So to compare the results I should lock my car as well and then see what happens.

When you say "decreased to 0.06 a", when did you do this, and how much was it before you removed the connector?

I'm not really sure how to check the wire layout more more then I did. The wiper assembly is mirrored from the English cars (LHD vs RHD), and I've noticed that the English wiper motor unit is "upside down" from mine. Maybe this requires the pin layout to differ from mine?
All I can say is that the front of the connector has 4 small numbers carved upside-down into the plastic. Black has number 1, blue/green is number 2, red/green is number 3 and brown/green is number 4.
Apparently the LHD version has partnumber: DKD100510. When you throw this in Google Images it gives me 2 images that show the same wire-colors as mine:
https://rrr.lt/image/part/11218698/0...4782644887.jpg
https://cdn-fs.opisto.fr/Pictures/21...226e25fa93.jpg

I just rotated the dial to show what happens. Normally I leave this alone. I'll continue leaving it alone .

Originally Posted by colintf

They are well known in MG circles, particularly MGB and earlier, but do all MG's. I know them well, they come over to the uk a few times a year, and I see them overseas a few times. They've converted a classic to an electric car as well, so they know electrics. Give them a call and ask for Cat or Thjys, say I (Colin Murrell) suggested you call them) they may offer to help or point you in the right direction


https://www.mgworkshop.nl/en

Thanks Colin. I'll try to give them a call tomorrow. Never hurts to try.

[DeeJ]

Hi from Son en Breugel Vinnie.

Just went to check the wife's V6 left out front since day 1of the corona "intelligent"(?) lockdown over two months ago, and it started instantly. Uses the same Varta Silver (1 year old) as my V8. Unbelievable. Still has all the Hi-line gubbins in too. Doesn't help you to know, but if you want to pop around to look at something, or borrow/steal something, you are welcome (if you stay 1,5m away!) I have 3 V6's sitting around awaiting the scrappy or a needy sole. PM (>DeeJ) if you like.

David

[SD1too]

Originally Posted by Supervinnie40

When you say "decreased to 0.06 A" ... how much was it before you removed the connector?

0.1 A Vinnie, as said in numbered point 3. in the same post.
I'm getting the same results as you are, a lower current with the wiper connector removed.

Originally Posted by Supervinnie40

Black has number 1, blue/green is number 2, red/green is number 3 and brown/green is number 4.

Thanks for confirming. It's bizarre that a LHD car should have the wires transposed on pins 1 and 4.

Anyway, both our cars seem to behave approximately the same way so maybe it's normal for 70 to 100 mA to be drawn intermittently. I checked MGR's wording which said that the figures are "a guide" so maybe not to be taken too literally.

If it's any consolation, as a precaution I charged my battery fully when our lockdown began and it was utterly flat after two months lack of use.

Simon

[Supervinnie40]

Originally Posted by DeeJ

Hi from Son en Breugel Vinnie.

Just went to check the wife's V6 left out front since day 1of the corona "intelligent"(?) lockdown over two months ago, and it started instantly. Uses the same Varta Silver (1 year old) as my V8. Unbelievable. Still has all the Hi-line gubbins in too. Doesn't help you to know, but if you want to pop around to look at something, or borrow/steal something, you are welcome (if you stay 1,5m away!) I have 3 V6's sitting around awaiting the scrappy or a needy sole. PM (>DeeJ) if you like.

David

Thanks David! That might be usefull once we know if something needs to be changed. On a very unrelated note, do you have the service manuals from one of those to-be-scrapped cars? I'm looking for a book to write down the service I did myself. Cleaner that a notepad and I don't want to write in the book that's used by the dealer.
Once we know if something needs to be replaced I'm sure to get in contact with you.

Originally Posted by SD1too

0.1 A Vinnie, as said in numbered point 3. in the same post.
I'm getting the same results as you are, a lower current with the wiper connector removed.

Thanks for confirming. It's bizarre that a LHD car should have the wires transposed on pins 1 and 4.

Anyway, both our cars seem to behave approximately the same way so maybe it's normal for 70 to 100 mA to be drawn intermittently. I checked MGR's wording which said that the figures are "a guide" so maybe not to be taken too literally.

If it's any consolation, as a precaution I charged my battery fully when our lockdown began and it was utterly flat after two months lack of use.

Simon

Sorry, seems I misread your post.

Weird thought, but could a drain increase with age? Wouldn't really know how, but it makes me wonder.

I've got my car locked at the moment with the multimeter in series. I'll check in an hour orso to see what it says. That would make a better comparison with your readings.

[SD1too]

Originally Posted by DeeJ

Just went to check the wife's V6 ... and it started instantly.

Hi David,

If you own a multimeter would you be willing to check its quiescent current consumption? Results from a third KV6 would be useful.

Simon

[DeeJ]

Originally Posted by SD1too

Hi David,

If you own a multimeter would you be willing to check its quiescent current consumption? Results from a third KV6 would be useful.

Simon

Best way of doing that, Simon, to avoid me muddying the waters by info based on my total electrical incompetence ?

David