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Mercedes-Benz A-Class key battery

W177

2018–2024
How to change a smart key battery
  1. Slide the release catch and pull out the emergency key blade.
  2. Wrap the tip of a small flat screwdriver in tape or a cloth, put it in the slot the blade leaves and twist gently to part the case. Keep it off the circuit board and contacts.
  3. Note which way up the old cell sits before you lift it out. It varies by key, so don't assume + is up.
  4. Fit a new CR2032 the same way up, holding it by the edges. Leave any grease on the contacts.
  5. Clip the case back together and test the buttons at the car. Most keys work straight away with no reprogramming.
  6. Keep new and old cells away from children. A swallowed button battery can cause serious injury within two hours.
Full A-Class W177 key record

W176

2012–2018
How to change a smart key battery
  1. Slide the release catch and pull out the emergency key blade.
  2. Wrap the tip of a small flat screwdriver in tape or a cloth, put it in the slot the blade leaves and twist gently to part the case. Keep it off the circuit board and contacts.
  3. Note which way up the old cell sits before you lift it out. It varies by key, so don't assume + is up.
  4. Fit a new CR2032 the same way up, holding it by the edges. Leave any grease on the contacts.
  5. Clip the case back together and test the buttons at the car. Most keys work straight away with no reprogramming.
  6. Keep new and old cells away from children. A swallowed button battery can cause serious injury within two hours.
Full A-Class W176 key record

W169

2004–2012
  • Remote head keyNot confirmed

    We haven't confirmed this one. Open the key and read the code on the old cell, then buy the same.

Full A-Class W169 key record

W168

1997–2004
Full A-Class W168 key record

Australian and NZ models

W169

2004–2012
  • Remote head key2 × CR2025

    Takes two cells. Replace both at the same time, stacked the same way as the old ones.

  • Remote head keyCR2025
Full A-Class W169 key record

For locksmiths · W177

  • KeysSmart key
  • Tools confirmed5
  • Transponder chipSubscribers
  • Programming procedureSubscribers
Subscribe for the full recordFull A-Class W177 key record

Questions

Mercedes-Benz A-Class key battery questions

W177 (2018–2024): CR2032 in the smart key. W176 (2012–2018): CR2032 in the smart key. W168 (1997–2004): CR2025 in the remote head key.

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