Key slot voltage

[bp05]

Does anyone know the voltage for the key slot? I plan to do an experiment.

I want to power up the slot at home so I can inductively charge the key so it won't be dead all the time.

Part number for the key slot: 66129172369

[printerror]

You know it takes about 30 seconds to change the battery, right?

[bp05]

Originally Posted by printerror

You know it takes about 30 seconds to change the battery, right?

Yes, I do.

But I don't have comfort access.

You know there's a difference between key fobs, right?


Why my question:

I'm trying to find what voltage the key fob slot outputs to charge the NON-COMFORT ACCESS key, so I can have a baseline on what specs I would need for a DIY wireless charger.

I bought a Sonicare toothbrush charger, and it doesn't seem to give a charge like with the older diamond style key.

[Gangplank]

Sup'd. Curious how this turns out.

[bp05]

Originally Posted by Gangplank

Sup'd. Curious how this turns out.

It will be interesting!

Just did more research.

From another thread on here, it states the key fob uses the Panasonic VL2020 coin battery.

I found the specs of the battery and it's charging requirements.
It's attached in the picture.

Now to figure out how to power that extra key slot. It looks like there's a ribbon cable that attaches to the key slot. My guess is that it's a 5V line, but I'll have to take a multimeter to it.

Pic of said ribbon cable:



Plan is to buy a used key slot, create power and ground connection of either 5V or 12V, then see if the sucker charges the key.

Note:
Bought the car approx ~1 month ago. The key was dead at the dealership when I first went to test drive it.

After a 4 hour ride back home, stopping at a gas station to fill up, they key started working again for the next few weeks, until I had to fly out for work, thus the battery died.

[tuj]

I'd try to sniff out how the key-reader that the SA uses works. My guess...5v.

http://www.ebay.com/itm/BMW-KEY-READ...312505&vxp=mtr

[bp05]

Originally Posted by tuj

I'd try to sniff out how the key-reader that the SA uses works. My guess...5v.

http://www.ebay.com/itm/BMW-KEY-READ...312505&vxp=mtr

5V was my guess. Good idea about checking voltage for key readers!

Edit:
Looks like the key reader is 12V. I'm going to have to make sure with a multimeter what the voltage actually is in the car. Don't want to blow up a $60+ part.

[Gangplank]

$60+? I recently bought a key (non-conf. access). They are damn near $300

[bp05]

Originally Posted by Gangplank

$60+? I recently bought a key (non-conf. access). They are damn near $300

Sorry for the confusion. The part that is $60 is a used key ignition slot. The one in your dashboard.

[Gangplank]

Oh. Ok that makes sense

[bp05]

Originally Posted by Gangplank

$60+? I recently bought a key (non-conf. access). They are damn near $300

BTW, Did you buy the key fob WITH the actual metal key? Or just the FOB remote itself?

[Gangplank]

Originally Posted by bp05

BTW, Did you buy the key fob WITH the actual metal key? Or just the FOB remote itself?

I needed both b/c my car only came with 1 when I bought it.

[Downeaster1]

Keep me posted on this, I'm actually very curious.

[bp05]

Originally Posted by Downeaster1

Keep me posted on this, I'm actually very curious.

Been busy. Haven't had time to take voltages. Still looking into it

[Downeaster1]

It should be a constant 12v as long as a signal was passed along the wakeup bus.

[bp05]

Originally Posted by Downeaster1

It should be a constant 12v as long as a signal was passed along the wakeup bus.

SUPER late reply. Been busy with the day job :/

Anyway, 12v constant? I'll check.. Need to find my multimeter.

I wish there was a pinout online. I've been searching to find which pin is power and ground.

[Downeaster1]

Originally Posted by bp05

SUPER late reply. Been busy with the day job :/

Anyway, 12v constant? I'll check.. Need to find my multimeter.

I wish there was a pinout online. I've been searching to find which pin is power and ground.

I'll grab it from ISTA now.

[bp05]

Originally Posted by Downeaster1

I'll grab it from ISTA now.

Were you able to find anything?

[Dackelone]

Wouldn't it just be easier to DRIVE your car and swap out your keys each time you drive the car ? I don't have CA on my car and sometimes I don't drive my car for a month or two... and I never have trouble with my key fobs. I do try to use the fob that sits unused from time to time. But still I've never had one go "dead".

On my old e39 540i when I bought that car one of the remote keys(also a sealed unit, like used on e46's) worked very weak. After driving the car every day for say 30 minute drives(each way) for a week or so - the key(remote) works just like it should. It helps going for long one hour drives. Short drives the key doesn't get charged that much in the slot. Think of it as spending some quality time with your car.

[bp05]

Originally Posted by Dackelone

Wouldn't it just be easier to DRIVE your car and swap out your keys each time you drive the car ? I don't have CA on my car and sometimes I don't drive my car for a month or two... and I never have trouble with my key fobs. I do try to use the fob that sits unused from time to time. But still I've never had one go "dead".

On my old e39 540i when I bought that car one of the remote keys(also a sealed unit, like used on e46's) worked very weak. After driving the car every day for say 30 minute drives(each way) for a week or so - the key(remote) works just like it should. It helps going for long one hour drives. Short drives the key doesn't get charged that much in the slot. Think of it as spending some quality time with your car.

I have driven for one hour, and it still is dead.

I ended up buying another fob itself. Was only $130 for the fob without the key.