This worked a treat - Totally spot on Chris - 30seconds for each key fob once you prized the bits apart. Batteries seem to fade after 4 years.
Mk3 Keyfob Battery Replacement
Here's a quick how to, with pictures, for replacing the MX-5 Mk3 battery in the remote keyfob unit.
1. Firstly, your key should look like this.
![Gadget Material property Peripheral Font Electronic device]()
2. Look closely at the key recess, there's a small plastic hole and tab.
![Tire Automotive tire Tread Wood Synthetic rubber]()
3. Insert a small flat bladed screwdriver into the hole and carefully but firmly push the main "remote" unit down and away from the top "key section" as shown.
![Composite material Bicycle part Metal Steel Titanium]()
4. The two sections should come apart easily from this point.
![Automotive tire Tire Audio equipment Automotive wheel system Auto part]()
5. Let's take a closer look at the main unit body. See the white triangle? It's pointing to a recessed tab shown by the red arrow in the picture. Use the small bladed screwdriver to lift the top section apart. It's quite tricky if the unit has never been opened before.
![Automotive tire Hood Automotive lighting Vehicle Bumper]()
6. You should now have two halves. Note the battery location and the polarity. Very gently, flip the battery out with the screwdriver.
![Circuit component Passive circuit component Hardware programmer Electronic component Electronic engineering]()
7. Ping! The battery type is a CR1620 3V cell. Often found at watch repair or key cutting shops. They're usually cheaper per unit online, though you may wind up buying several.
![Measuring instrument Machine Font Gas Electronics accessory]()
8. Pop your new battery in place, again remembering the polarity. It should be as shown: negative side up, positive side down.
![Circuit component Hardware programmer Passive circuit component Electronic engineering Electronic component]()
9. Fix the two halves of the "remote" section together firmly.
![Product Input device Computer keyboard Peripheral Office equipment]()
10. Slide the "key section" back onto the "remote" section and you're done.
![Car alarm Musical instrument accessory Gadget Gas Audio equipment]()
All attached thumbnails in sequence:
![Gadget Material property Peripheral Font Electronic device]()
![Tire Automotive tire Tread Wood Synthetic rubber]()
![Composite material Bicycle part Metal Steel Titanium]()
![Automotive tire Tire Audio equipment Automotive wheel system Auto part]()
![Automotive tire Hood Automotive lighting Vehicle Bumper]()
![Circuit component Passive circuit component Hardware programmer Electronic component Electronic engineering]()
![Measuring instrument Machine Font Gas Electronics accessory]()
![Circuit component Hardware programmer Passive circuit component Electronic engineering Electronic component]()
![Product Input device Computer keyboard Peripheral Office equipment]()
![Car alarm Musical instrument accessory Gadget Gas Audio equipment]()
1. Firstly, your key should look like this.
2. Look closely at the key recess, there's a small plastic hole and tab.
3. Insert a small flat bladed screwdriver into the hole and carefully but firmly push the main "remote" unit down and away from the top "key section" as shown.
4. The two sections should come apart easily from this point.
5. Let's take a closer look at the main unit body. See the white triangle? It's pointing to a recessed tab shown by the red arrow in the picture. Use the small bladed screwdriver to lift the top section apart. It's quite tricky if the unit has never been opened before.
6. You should now have two halves. Note the battery location and the polarity. Very gently, flip the battery out with the screwdriver.
7. Ping! The battery type is a CR1620 3V cell. Often found at watch repair or key cutting shops. They're usually cheaper per unit online, though you may wind up buying several.
8. Pop your new battery in place, again remembering the polarity. It should be as shown: negative side up, positive side down.
9. Fix the two halves of the "remote" section together firmly.
10. Slide the "key section" back onto the "remote" section and you're done.
All attached thumbnails in sequence:
