Battery Maintainer Wiring?

Just purchased a new Ctek Multi US 7002 and was wondering where the best place to wire it would be?

Can it be wired under the the hood? Or would it have to wired directly to trunk in battery?

Do read the manual before trying anything! As these cars have stop/start they have some massive capacitors and if you connect wrong, your going to really mess stuff up.

I think it would have to be the engine bay points for jump starting cars. You can't jumpstart off of the battery (Cables will melt! Trust me!) so for trickle feed I'd guess it has to be the engine bay.

larrymz3 said:

Just purchased a new Ctek Multi US 7002 and was wondering where the best place to wire it would be?

Can it be wired under the the hood? Or would it have to wired directly to trunk in battery?

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Good question.
I was thinking about this myself.
I think that you could connect to the posts in the engine bay or to the battery in the trunk (either should work).
I am a little concerned about opening the hood frequently to connect to the maintainer because of the hood's large size and potential for misalignment/panel gaps.
So I will most likely connect the maintainer somewhere in the trunk (to the battery or someplace close by).

A90 Zero said:

Good question.
I was thinking about this myself.
I think that you could connect to the posts in the engine bay or to the battery in the trunk (either should work).
I am a little concerned about opening the hood frequently to connect to the maintainer because of the hood's large size and potential for misalignment/panel gaps.
So I will most likely connect the maintainer somewhere in the trunk (to the battery or someplace close by).

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I'm thinking of picking this up: https://smartercharger.com/collections/accessories/products/ctek-comfort-indicator-panel

This would allow me to mount to a side panel in the trunk and quickly plug in the charger (as well as quickly see charging status).

I may also get this: https://smartercharger.com/collections/accessories/products/ctek-ctx-battery-sense

Do we know which of the circuits in the trunk it's okay to hook the cameras up to so that it doesn't drain them when the car is turned off and result in battery issues? I would still plan on hooking up a third-party battery between the camera and the car's battery, but I'm just wondering if anyone knows which ports are correct for this purpose as it seems like even mechanics / specialists are messing this up and causing warning messages to appear.

Supra Dupra said:

Do we know which of the circuits in the trunk it's okay to hook the cameras up to so that it doesn't drain them when the car is turned off and result in battery issues? I would still plan on hooking up a third-party battery between the camera and the car's battery, but I'm just wondering if anyone knows which ports are correct for this purpose as it seems like even mechanics / specialists are messing this up and causing warning messages to appear.

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But wait... Wasn't that @RRKnight's car? And didn't it still cause battery issues even though it was plugged into those ports? I guess if that's causing issues I'm not sure how you could avoid the problem...

Supra Dupra said:

But wait... Wasn't that @RRKnight's car? And didn't it still cause battery issues even though it was plugged into those ports? I guess if that's causing issues I'm not sure how you could avoid the problem...

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That's actually someone else's car on this forum but I did go through them as well and ended up going back to install a dedicated battery. Wiring directly to the BMW even with the power meter contorller it still tripped an error messages with the battery. Now I'm waiting for the dealer to get a new battery to swap mine out.

RRKnight said:

That's actually someone else's car on this forum but I did go through them as well and ended up going back to install a dedicated battery. Wiring directly to the BMW even with the power meter contorller it still tripped an error messages with the battery. Now I'm waiting for the dealer to get a new battery to swap mine out.

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So is the solution to tap into that 12v port as shown in that video using a relay but instead of hooking the relay directly up to the cameras, to hook it up to a battery, and then plug the battery into the cameras? It seems like something (this time, the battery) would still be drawing power from that circuit which, based on how the "smart" BMW battery operates, would still trigger the error message, would it not? Or did the other person on here do the same thing as you but with a battery and they haven't had any error messages yet? I guess I'm still not understanding how your install was even problematic to begin with if it was tapping into that circuit that doesn't pull power from the battery when the car is turned off...

Supra Dupra said:

So is the solution to tap into that 12v port as shown in that video using a relay but instead of hooking the relay directly up to the cameras, to hook it up to a battery, and then plug the battery into the cameras? It seems like something (this time, the battery) would still be drawing power from that circuit which, based on how the "smart" BMW battery operates, would still trigger the error message, would it not? Or did the other person on here do the same thing as you but with a battery and they haven't had any error messages yet? I guess I'm still not understanding how your install was even problematic to begin with if it was tapping into that circuit that doesn't pull power from the battery when the car is turned off...

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Yes but the difference is that it will only draw power from the car battery when the car is on to charge the separate battery and only uses the separate battery when the car is off. The battery error message is probably when the camera is drawing power from the car battery when it's off and making it weaker. The computer might think it's a faulty battery.

RRKnight said:

Yes but the difference is that it will only draw power from the car battery when the car is on to charge the separate battery and only uses the separate battery when the car is off. The battery error message is probably when the camera is drawing power from the car battery when it's off and making it weaker. The computer might think it's a faulty battery.

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I guess my concern is how does the Blackvue (or other external) battery know not to draw on that same circuit when the car is powered off if the Blackvue cameras didn’t know not to? Is the Blackvue battery pack “smarter” than their cameras in that regard? If not, I’m not understanding how the Blackvue battery pack won’t cause the same issue.

Supra Dupra said:

I guess my concern is how does the Blackvue (or other external) battery know not to draw on that same circuit when the car is powered off if the Blackvue cameras didn’t know not to? Is the Blackvue battery pack “smarter” than their cameras in that regard? If not, I’m not understanding how the Blackvue battery pack won’t cause the same issue.

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I didn't do the install so I can't tell you how but I'm pretty sure you can YouTube it.

Would powering an amp for audio cause issues with the battery?

My solution is: My dashcam is plugged into the USB port of the entertainment system. The USB port does not immediatedly switch off when the engine is stopped with the Start/Stop button. But, after a while (I think 2 or 3 minutes, depends on whether you lock the car or not), the USB port is currentless and the dashcam switches off.

Probably, however, it is better to return to the original topic of this thread, i.e. where to plug a battery charger.

Not knowing about issues and by default not reading manuals (because of my extreme cleverness ;-)), I already plugged my battery charger into the 12V port in the trunk on the first day after delivery. The battery was charged over night and I had no electric damage or error message. Probably, the electric system of the car has respect for my cleverness. I assume, however, I was simply a lucky man. The car was locked over night.

Since the battery charger (of CTEK) also has a battery maintaining function, I can image, that battery maintaining over a longer period works as well. CTEK offers a 12V plug adapter.

Regarding the power wiring for the dash cams -- you have to find a switched 12V power source that shuts off when the car is off. This is required whether or not you have a camera battery pack installed. Nothing should be pulling power from the car when it's shut off, not the camera and not the battery pack.

The way it will work is that the camera always draws from the battery pack, never from the car directly. When the car is on, the battery pack is being recharged. When the car is off, nothing is drawing from the car. The camera will run as long as the battery pack lasts.

I've seen people talk about just adding the battery pack without changing the power source, and that won't help at all, eventually you will still have a problem. Also, don't use any device that purports to monitor the voltage and shut off at a preset limit, that won't help either. The camera and its battery pack need to be wired so that they are not drawing any power from the car when the car is turned off, under any circumstances.

Not all installers are hip to this, so be sure to talk it over with them and make sure they are tying into a circuit that gets cut off when the car is off. This is not hard, just requires some minor knowledge of BMW electrical systems and/or some careful testing with a voltmeter.