[marcw]

Went into the garage today and noticed the trickle charger on my M2 make what appears to be relay clicking noises every 5 seconds.

I unplugged the charger let it sit for a bit and plugged it back in. As expected the relay clicks as the charger goes from no charge to quarter charged to half charged etc. but it never makes it to green fully charged. This happens in both normal and AGM mode.

I have an identical 7002 trickle charging my Jag. It showed happily green, fully charged. So I swapped the two. And now the one from the Jag is doing the same thing on the M2. So doesn’t seem to be the charger at issue here.

Has anyone experienced this on their M2?

[F87source]

The clicking sound is the relay starting and stopping the charging process. I have the same clicking on my m2, but not every 5 seconds. Just once in awhile when the battery starts to drain, like if I open the door and turn on the accessory mode I can hear the relay click as the battery voltage dips.


ok but the problem here is you said it never fully charges? Have you left it on the m2 for 24 hours? And where is it connected on the m2?

[marcw]

Originally Posted by F87source

The clicking sound is the relay starting and stopping the charging process. I have the same clicking on my m2, but not every 5 seconds. Just once in awhile when the battery starts to drain, like if I open the door and turn on the accessory mode I can hear the relay click as the battery voltage dips.


ok but the problem here is you said it never fully charges? Have you left it on the m2 for 24 hours? And where is it connected on the m2?

It’s been charging the M2 since I put it into hybernation mode last November. The car is locked and should be fully asleep with minimal charge drawing from the battery. I looked at that charger maybe a month ago and it showed green no clicking. I wouldn’t event have looked at it today if I wouldn’t have wondered where the clicking noise was coming from.

I’ve seen the kind on behavior you are describing. When green and then you open the door and the interior lights come and the charger clicks and goes to orange. But this is different. It just sits there clicking every 4-5 second never coming off the third light.

Charger is connected at the connector points under the hood not directly to the battery.

[F87source]

Originally Posted by marcw

It’s been charging the M2 since I put it into hybernation mode last November. The car is locked and should be fully asleep with minimal charge drawing from the battery. I looked at that charger maybe a month ago and it showed green no clicking. I wouldn’t event have looked at it today if I wouldn’t have wondered where the clicking noise was coming from.

I’ve seen the kind on behavior you are describing. When green and then you open the door and the interior lights come and the charger clicks and goes to orange. But this is different. It just sits there clicking every 4-5 second never coming off the third light.

Charger is connected at the connector points under the hood not directly to the battery.

Interesting I'm not sure why this is occuring, maybe the cars stopping the charge. Are you able to get diagnostics info from the m2?

[Noh Wan]

Maybe a short somewhere or a shorted cell in the battery? That would cause the charger to see low enough voltage to kick off the charge cycle, but once it kicked on the voltage would almost immediately read high and shut down, only for the charger to see low voltage again.

Have you checked the battery voltage independent of the charger or checked to see if the car cranks over fine? It would be a surprise if it's a dead cell, but I've seen crazier things.

That said, definitely don't leave the charger on it. If it IS a dead cell everytime the charger kicks on it's trying to squeeze a little more juice into the good cells and can overcharge them creating a dangerous situation. Ctek is supposed to have pretty decent protection built-in to prevent it but I wouldn't want to test it in my garage!

[doughboy]

Check standing volts with a meter on the battery direct. No charger, no ignition on.

Should be close to 12v if its fairly well charged.

Try the charger direct on m2 battery rather than on the jump start post in the front. You know the charger is setting correct battery condition then not being interfered with by any other electronics.

I always run mine that way.

[F87source]

Originally Posted by doughboy

Try it direct on m2 battery rather than on the jump start post in the front.

I always run mine that way.

No that bypasses the IBS, and can lead to damages both to the battery and the IBS. The reason why is when you charge through the underwood posts the IBS is still in place to monitor and charge the battery. Also when charging the battery directly if you get a power surge you will damage the IBS, or you can over charge the battery.

Technically this is less likely to occur with the ctek because of it's intelligent monitoring, and extremely good hardware meaning low ripple and low potential of surge. However it's always bettery to do it under hood.


Op should get OBD2 diagnostic codes to make sure nothing is going on with the car (this is more accurate than experimentation imo). If op wants to try directly on the battery, unplug it from the car.



It could also be because the car thinks the battery is old and therefore not capable of accepting a full charge so the IBS is cutting charge off early (which is what it naturally does as the battery gets older), you could also use ISTA to check battery health and or capacity.

[doughboy]

I've looked into this before and I work with large lead acid DC power system in utilities.

Lead acid batteries are very robust and have been around a long time without any IBS involved. They'll take no end of a beating charge and discharge wise and lap it up. They make great sinks for voltage spikes and ripple etc.

Any surge on the underhood post will be forced through the ibs on its way to the battery whereas a surge direct on the battery will be absorbed by the battery and less likey to stress the ibs. Although the ibs is a pretty rugged device anyway.

The IBS can't effect charging itself as it's only a intelligent measuring device. It sends data to the DME so that the DME can regulate alternator output to control engine powered charging to suit battery age and condition.

Also key in my view with charging direct on the battery means about 5 metres less wiring, it's important to have the most accurate voltage measurement when charging batteries so shorter connection the better.

That's a key function of IBS to measure volts right at the battery and report back as data to the DME.

It's a clever thing but all it does is measure current, volts and temp.


Each to there own but i know where I'm connecting my charger!


.

[F87source]

Originally Posted by doughboy

I've looked into this before and I work with large lead acid DC power system in utilities.

Lead acid batteries are very robust and have been around a long time without any IBS involved. They'll take no end of a beating charge and discharge wise and lap it up. They make great sinks for voltage spikes and ripple etc.

Any surge on the underhood post will be forced through the ibs on its way to the battery whereas a surge direct on the battery will be absorbed by the battery and less likey to stress the ibs. Although the ibs is a pretty rugged device anyway.

The IBS can't effect charging itself as it's only a intelligent measuring device. It sends data to the DME so that the DME can regulate alternator output to control engine powered charging to suit battery age and condition.

Also key in my view with charging direct on the battery means about 5 metres less wiring, it's important to have the most accurate voltage measurement when charging batteries so shorter connection the better.

That's a key function of IBS to measure volts right at the battery and report back as data to the DME.

It's a clever thing but all it does is measure current, volts and temp.


Each to there own but i know where I'm connecting my charger!


.

The IBS isn't as durable as you think it is, I've seen alot of them die before (from charging there) - but especially after jump starting directly to the battery.


Ok this is why I believe charging under the hood is better, not because the IBS is able to influence how much charge gets to the battery (voltage etc) but it is able to monitor the battery charging itself. This means when it gets to a state where it think it is too full it can "abort" the charging by opening the relay - which the underhood terminals are connected to. It's part of the ecu's that are always on to monitor the car. At least I believe this was the case, there was some discussion on it awhile ago and I can try to find it.


Either way bmw stipulates to charge only via the under hood terminals.

[DadVibes]

My first Ctek 7002 had the same issue, clicking every 3-5 seconds. I read that it was normal behavior. But it continued to concern me.

I had it replaced and the second one resolved the issue. Working flawlessly for the last ~3 months.

FWIW - I use the posts in the engine compartment. Not directly on the battery.

[doughboy]

Originally Posted by F87source

The IBS isn't as durable as you think it is, I've seen alot of them die before (from charging there) - but especially after jump starting directly to the battery.


Ok this is why I believe charging under the hood is better, not because the IBS is able to influence how much charge gets to the battery (voltage etc) but it is able to monitor the battery charging itself. This means when it gets to a state where it think it is too full it can "abort" the charging by opening the relay - which the underhood terminals are connected to. It's part of the ecu's that are always on to monitor the car. At least I believe this was the case, there was some discussion on it awhile ago and I can try to find it.


Either way bmw stipulates to charge only via the under hood terminals.

Yes I would say jump starting at the battery location is really pointless / foolish when the engine bay terminals deliver the current right near where its needed close to the starter.

The IBS can't action anything itself, it only logs data for every 14seconds and then passes that to the DME when the ignition next gets turned on.

There may be a relay on the positive underhood post (i'll check on ISTA circuit diagrams next time I'm on it) but the IBS can't control that when the ignition is off, and I'd trust a ctek to know when the battery is charged more than the IBS anyway. Especially if you're recon-ing a battery by pushing it outside normal operating levels.

Plenty of manufacturers have moved the battery out of easy reach for packaging reasons and provided under hood posts which are safe and easy to use so they will always recommend using them, keeps customers away from nasty lead acid cells and wiring etc.

But to get as accurate a battery voltage to/from your ctek charger (which is key for lead acid charging) the shorter the leads the better.