Key Fob Battery Replacement Continued......

[o. l. t.]

Noting MrbmwX5's Key Fob DIY I grabbed the battery from Mouser, but instead of the vertical I grabbed BOTH Horizontal and Vertical because I read the issue with bending pins, snapping them off and reusing them, etc.... NO NEED, just get the vertical one instead.

The biggest difference of any value to you is that the pins are on the opposite sides facing opposite directions on the vertical whereas on the horizontal they are both facing the same way AND on the same side as well! (That's exactly what you want, see images below).









As you can see the vertical battery will need a good bit of work to fit, while the horizontal battery pins line right up and solder in with only a slight widening of their direction.

I recommend the horizontal pin version. In the end neither are perfect and both will work. This thread is just to show the differences in the two batteries so you can make your decision.

[mrbmwx5]

At the time they didn't have the horizontal pin version ,so I went with the Vertical version.
Now all you need is LIQUID NAILS Adhesive and put it along the fob.... Then paint it with some black nails polish.

[o. l. t.]

They need a BMW key fob version. Then you wouldn't have to do anything at all.

I have clear epoxy I use on the Lexus stuff we work on. Do it from the inside since the outside is cut clean. Never know.......

[Turbo_Bimmer]

Excuse my ignorance, but what 'fob' stands for?

[romeokc10]

I replaced the battery in my key fob and now only the trunk will unlock, but man does it have great range..lol, and yes I tried all of the reprogramming threads.

[Turbo_Bimmer]

Originally Posted by Turbo_Bimmer

Excuse my ignorance, but what 'fob' stands for?

I think I found it:

Fractional Orbital Bombardment ... or may be
Freight On Board

nah,
I had to go to the end of Internet and come back with this:

The word fob is believed to have originated from watch fobs, which existed as early as 1888. The fob refers to an ornament attached to a pocket-watch chain. Key chains, car starters, garage door openers, and keyless entry devices on hotel room doors are also called fobs.

One more word to add to my english vocabulary

[o. l. t.]

While I was working on replacing the battery I took some voltage readings and probed the fob so if it ever goes down I know what it is supposed to be reading.

Red indicates positive.


3.3v at rest.


3.0v when under load while pressing a button and transmitting.


Close side 1.


Close side 2.

[dkl]

It looks like your original battery is still giving proper voltage level while under load...why did you decide to change the battery?

By the way...what did you use to get the "clean" cut? MrBMWX5 mentioned that he used an X-Acto knife, but that sound like it would take forever and the blade is strong enough to cut through the hard plastic without snapping off?

[o. l. t.]

I used a box cutter. Same sharpness, bigger stronger blade and handle gives more leverage.