How to: Replace the battery in your Lexus key fob

Eventually, the battery in your Lexus’ key fob will run low, and you’ll need to replace it. A Lexus Centre will be able to help, but if you’d rather do it yourself, here’s how…

Firstly, does your car have a conventional key which turns in the ignition or a smart key for a car which starts at the push of a button? The method for replacing the battery is slightly different depending on the key type.

Let’s start with the conventional ignition key. First of all, refer to the owner’s manual to check the type of battery you need, and source a replacement. Then find a small Phillips screwdriver, a coin (a 20p piece usually works well) and a paperclip.

On the back of the key you’ll see one or two Phillips screw heads.

If you can see one screw, use the screwdriver to remove it and put it somewhere safe – it’s a small screw and easy to lose if you’re not careful. Wiggle the back to unhook it from the rest of key and lift it off. Two more smaller screws hold the inside of the key together. Unscrew them to reveal the battery inside. Remove it (a paperclip will help to prise it out), then replace it with the new battery. Put the inside of the key back together using the two small screws. Then hook the back on and use the longer screw to hold it in place.

If the key fob is held together by two screws, unscrew both before pulling the back off. With this style of key there’s no hook so the back should pull straight off once the screws have been removed. Look for the words ‘coin open’ on the inside of the key next to a small hole. Hold the interior of the key firmly in one hand, insert a coin in the hole with your other hand and twist firmly. This will reveal the battery.

Use the paperclip to pop out the battery and insert the replacement, taking care that the battery is the right way up. Now clip the inside of the key back together. Line up the buttons with the holes on the outside of the key, then replace the back of the key and insert the screws to keep it in place.

Replacing the battery in a smart key is even easier. Slide across the release button for the metal key and pull it out of the fob. This will reveal a small indentation inside the key. Take the flat part of the key, put it in the indentation, and twist. The key will open to reveal the circuit board and battery.

Pop the battery out with the paperclip and replace it with the new one (a recent Lexus will need either a CR1632 or a CR1616). It should be held in place snugly. Line the battery up with the circular marking on the inside of the fob, then clip the other half of the fob on top. Replace the metal key in the fob to finish the job.

The exact method may vary slightly from model to model but, whichever Lexus you own, replacing the key’s battery should be straightforward. But don’t forget, if you’d rather not do it yourself your local Lexus Centre will be able to help you.


  1. I have a Lexus CT200h, and the 4 tiny screws that hold the battery cover inside the key fob are wearing out.
    Could you confirm their size, please?
    I have read the required screw size is 1.6mm thread diameter., 3mm thread length, with a flat head.
    We also have an IS300h in the family, would the same size screws fit there as well?
    Thanks in advance!

      1. Thanks for the quick response.
        The CT200h is a LHD vehicle, which is not registered in the UK. It was first registered in Austria, in Jan. 2012. The key fob has 2 buttons (if this helps).
        Thanks in advance!

  2. I had one notice from the car’s messaging system that I had a low battery in my key fob. Can I replace the battery without having anything else done like having to have it reprogrammed?

    1. Hello Dale, thanks for your question.

      We would recommend contacting your Lexus Centre for assistance on this.


    2. A competent locksmith can also replace the key fob’s battery as well as reprogram extra key fobs, just ask around.
      It will be 65% less expensive than having the same done at the Lexus dealer.
      Luckily , I have just such a person (Houston, TX) and was able to get two key fob batteries replaced as well as one key fob reprogrammed for my Lexus LS460-F, for a grand total of $175.
      I doubt that a dealer cn match that.
      And before you ask, yes, everything works perfectly, and this was 3-years ago.

  3. Not a good illustration video, it skips over the separation of the key fob. I seem to be doing more damage in trying to split the fob, showing the process would help.
    Not anyway near a Lexus dealer to assist

    1. Hi Neil, thanks for getting in contact.

      We’re sorry to hear you are experiencing issues replacing the battery in your key fob.

      We would recommend calling a centre for advice with this, as it could be clearer to explain over the phone.

      You can locate your closest Lexus Centre and their telephone number here:

      Please let us know if you need any more assistance.


  4. I replaced the battery in one key fob (2015 CT200h) but there is no response from the car – is there some procedure to reconfigure car and fob?

  5. Poor video. Makes opening the fob sound easy … but it isn’t. Feel sure if I use any more force, I will damage the fob. Ridiculous to need to go the 15 miles each way to my nearest dealer. Please give more advice on how to do this regular diy task

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