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R55/R56 Key Fob rechargeable battery FIX

145K views 16 replies 14 participants last post by  demongrl123 
#1 · (Edited by Moderator)
Hi hi, just want to share my successful replacement of the rechargeable battery of my R55 Key Fob. I have been using my car for more than 5 years and one of my keys was out of juice a few months ago. Though I put it back in the ignition key inserting place and drive for recharging the key fob, it was still malfunctioning.
I asked the BMW shop in HK and they said the key could not be repaired and it costs about HK$3500 for a new one including coding and engraving the key.

I tried to source the internet and strangely that no topic talking about how to repair the key fob (perhaps some for BMW which is more or less the same). Luckily I saw a topic "R56 Keyfob disassembled" which is somehow relevant and then I tried to fix it by myself.

Special Thanks to Milski who gave my guidance on how to remove the casing.

Materials/Equipment required
1. Cutter
2. key fob ring (cuz the original plastic one must be damaged when taken down) (I had replaced a new metal ring for few years.
3. solder gun (no need to solder tin cuz the original one could be reused)
4. Panasonxx VL-2020 3V (180degree) rechargeable battery (can be bought from eBay or Taobao) It costs not more than HK$50 for 1 pc.
5. glue (for reassembling)

Method:
1. remove the existing ring and the mechanical key
2. use a sharp cutter and insert it into the gap of the key fob and cut off the original glue carefully. as it is unavoidably making scratches on the key fob, so it is suggested to cut off the glue at the hidden part by the key fob ring (not at the engraved key side which is exposed)

3. after a while, the key fob will be separated like this.

4. bought a new battery from web or market. be sure it is 180degree (market has 90 degree).

5. Use a solder gun and carefully heat up the soldering tin of the footings of the existing battery and the battery will be dropped off. Remember don't heat up other parts of the electronic board.

6. use again the solder gun and carefully heat up the remained soldering tin on the terminal of the electronic board and insert the new battery into it.


7. Now, reassembling the key fob in reverse procedure. be careful that there are some small loosen parts, like the chrome button which is for releasing the mechanical key, the rubber for this chrome button.

8. glue the key fob. and reassemble the new key fob ring and mechanical key.

9. DONE

I tried the key with new battery for few days already and i can remote operate it in a further distance than my another 5-year key.

Cheers.
Vanon
 
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#5 ·
Yeah you right about it purely rechargeable by the magnetic field around it.Its an magnetic phenomenon.I studied deeply about that.But now i am experienced about it.However its a good achievement that you fix it well.Good job...
 
#6 ·
I failed at my attempt at this, and thought I'd post some photos to potentially help the next person. I used a box-cutter razor blade. I managed to not slice my fingers--DON'T BE DUMB as you work through this project.

I found I had the easiest time by starting on the fob's end, because the seam between the two halves is visible and exposed. Here, I am using toothpicks to hold the gap open as I cut and pried.

Once I got started, I kept cutting around the circumference. (Read about the disaster at the end of this post before you do like I did.)

As I was finishing the circumference, some components (and halves of components) started falling out--oops! My cutting went too deep and I had shaved at least six electronic components off of the circuit board.

HINDSIGHT
While I was able to pry apart the seam between the two clamshell halves at the end of the fob assembly, I was actually cutting the plastic around the circumference. In the circumference (in my fob at least), I don't think it would have been possible to pry the seam apart.

SITUATION that led me to this:
I had hardly used this fob in the past 1.5 years, while the wife was away at school. My 2008 MCS would run with the fob inserted into the slot, but the fob buttons could not open the doors remotely. I suspected that the battery was dead. I had read in other threads that an electric toothbrush charger can have more power than the Mini ignition slot, and I had tried that but it didn't charge the fob.

As I started the cutting project, I figured I didn't have anything to lose. In retrospect, we might have considered keeping a fob that runs the car but can't open the doors. Now the fob won't run the car, either, and I will be buying a new one.

Cheers!
 

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#8 · (Edited)
All might not be lost here. Your pictures are somewhat low resolution (forum's fault, not yours) but the only components I see that are damaged are two of the switches, and the button that holds the blade key in. I have had plenty of experience repairing the first generation keys (see threads below) and have shells and batteries in stock for the round, "Hockey Puck" keys like yours. The first generation keys use a different microswitch so I don't have those but they are easily found. If you'd like me to have a look at it I'd be eager to do so as I haven't worked on one yet. Even though I won't have access to your car, I can tell if it is operating properly by looking at a spectrum analyzer to see if it is putting out the correct radio frequency when the buttons are pushed. If the board is too damaged or I can't bring it back to life with a new battery and switches I will not charge you anything but return postage if you want it back.

PM me here or e-mail me at "valvashon (at) earthlink (dot) net".

Dr. Bruce Hart
MINI Key Hospital

Electrical: First Generation Key Refurbishment - North American Motoring

First Generation Key Refurib - Puget Sound MINI Motoring Club Forums

http://www.mini2.com/forum/first-generation-faults-fixes/198194-first-generation-clamshell-key-repair-guide.html
 
#9 ·
Thanks for the offer, but I'm going to leave it alone. The 6+ electronic damaged/removed components include damage of two of the three switches, several sheared-off resistors & capacitors, a sheared-off SOT-23 3-pin device, and I cut a resistor array in half.
 
#10 ·
having problem with ignition or key?

I have non-s 2012 Mini Copper(i know sucks) and when I place the key in the ignition none of the dash lights turn on or anything, but I can still unlock and lock the doors. The key that I have doesn't have the easy battery replacement like the Clubman, so I would have to do this method of replacing the key fob battery. My question though is it my key fob battery or the ignition in the car. If anyone has any theories let me know. A friend checked all the fuses so that's not the problem. Please and thank you.
 
#11 ·
I have non-s 2012 Mini Copper(i know sucks) and when I place the key in the ignition none of the dash lights turn on or anything, but I can still unlock and lock the doors. The key that I have doesn't have the easy battery replacement like the Clubman, so I would have to do this method of replacing the key fob battery. My question though is it my key fob battery or the ignition in the car. If anyone has any theories let me know. A friend checked all the fuses so that's not the problem. Please and thank you.
Did you find a solution? I am having the same problem. Key fob unlocks the doors and the lights/radio turn on. But the car will not start. My spare key works no problem. I have a Clubman, but it is not an easy battery replace.
 
#13 ·
Being new to Mini ownership,does this mean that the replacement battery is rechargable rather than a standard replacement one?
My spare key doesn't work and I was going to replace the casing as the button covers are missing and I was going go replace the battery at my local motor shop...unless that's not an option now.
 
#14 ·
Hi hi, just want to share my successful replacement of rechargeable battery of my R55 Key Fob. I have been using my car for more than 5 years and one of my key was out of juice few months ago. Though i put it back at the ignition key inserting place and drive for recharging the key fob, it was still malfunction.
I asked the BMW shop in HK and they said the key could not be repaired and it costs about HK$3500 for a new one including coding and engraving the key.

I tried to source the internet and strangely that no topic talking about how to repair the key fob (perhaps some for BMW which is more or less the same). Luckily I saw a topic "R56 Keyfob disassembled" which is somehow relevant and then I tried to fix it by myself.

Special Thanks to Millski who gave my the guidance on how to remove the casing.

Materials/Equipment required
1. Cutter
2. key fob ring (cuz the original plastic one must be damaged when taken down) (I had replaced a new metal ring for few years.
3. solder gun (no need soldering tin cuz the original one could be reused)
4. Panasonxx VL-2020 3V (180degree) rechargeable battery (can be bought from ebay or taobao) It costs not more than HK$50 for 1 pc.
5. glue (for reassembling)

Method:
1. remove the existing ring and the mechanical key
2. use a sharp cutter and insert it into the gap of the key fob and cut off the original glue carefully. as it is unavoidably making scratches on the key fob, so it is suggested to cut off the glue at the hidden part by the key fob ring (not at the engraved key side which is exposed)

3. after a while, the key fob will be separated like this.

4. bought a new battery from web or market. be sure it is 180degree (market has 90 degree).

5. Use a solder gun and carefully heat up the soldering tin of the footings of the existing battery and the battery will be dropped off. Remember don't heat up other parts of the electronic board.

6. use again the solder gun and carefully heat up the remained soldering tin on the terminal of the electronic board and insert the new battery into it.


7. Now, reassembling the key fob in reverse procedure. be careful that there are some small loosen parts, like the chrome button which is for releasing the mechanical key, the rubber for this chrome button.

8. glue the key fob. and reassemble the new key fob ring and mechanical key.

9. DONE

I tried the key with new battery for few days already and i can remote operate it in a further distance than my another 5-year key.

Cheers.
Vanon
Hi . I have replaced the battery as done here but the display still shows the key symbol regularly. is there a reset that has to be done ?
 
#15 ·
The other day I washed my key fob in the washer machine by accedent. When I noticed the key in the washer when I went to put my clothes in the dryer I took my key over to my car to make sure it still worked and it did, just as a precaution I did the rice trick to help dry out any moisture, now the buttons on the fob don't respond but it still starts the car, I opened it up to check battery voltage and it was at 2.80v don't know if this is to low a voltage for it to transmit a signal for lock/unlock and hatch, or if it happened to break when I dropped it? It was working fine after both incidents prior to ricing the key, just wondering if the battery voltage is insufficient or if I'm going to need a new key. Also if I replace the key will It reset the programing to my car?
 
#16 ·
I bought a new key fob about 18 months ago, which has unfortunately died on me already, so I am back down to one key fob—one of the originals that came with my 2009 MC S. Rather than dealing with slicing up the dead key fob (and probably my hands as well!), or shelling out another $350 for another new one, as the battery seems to recharge inductively, could anyone knowledgeable about electronics share his or her thoughts about possibly charging it up using those wireless pads for cellphones? Definitely not my field, but conceptually, if a pad would charge up a cellphone‘s battery that’s inside of it, wouldn’t it also work for the battery inside the key fob? Just this layperson’s thinking, but any feedback would be much appreciated!

While I absolutely love my Mini, this key fob battery situation is truly a PITA! (*-^)
 
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