CR1632 Key Fob Battery Guide: Specs, Fit and Replacement
A CR1632 is a 3V lithium manganese dioxide coin cell, 16 mm across and 3.2 mm thick, with roughly 120-140 mAh of capacity. In cars it is most often found in certain Toyota, Lexus, and Toyota-built Subaru/Scion smart keys from about the mid-2000s to mid-2010s. Confirm by reading your old battery.
The CR1632 looks like a shrunken CR2032: same 3.2 mm thickness, but only 16 mm wide. It packs more energy than the thinner 16 mm cells, which is why some smart keys that are always listening for the car use it.
Below are the specs, the fobs that commonly use it, the substitutes to avoid, and the replacement steps.
What Is a CR1632 Battery?
The code follows the IEC standard used by every major brand. “C” is lithium manganese dioxide chemistry, “R” means round, “16” is a 16 mm diameter, and “32” is a 3.2 mm thickness. Energizer labels it ECR1632 and Duracell labels it DL1632, but they are the same cell.
Like every CR coin cell, it has a nominal voltage of 3.0V and reads about 3.2-3.3V fresh. Typical capacity is about 120-140 mAh, roughly double a CR1620 and more than two and a half times a CR1616.
CR1632 Specs at a Glance
| Spec | CR1632 |
|---|---|
| Chemistry | Lithium manganese dioxide (Li-MnO2) |
| Nominal voltage | 3.0V |
| Fresh open-circuit voltage | About 3.2-3.3V |
| Diameter | 16 mm |
| Thickness | 3.2 mm |
| Typical capacity | Roughly 120-140 mAh |
| Brand equivalents | ECR1632, DL1632, and other CR1632-labeled cells |
Which Key Fobs Use a CR1632?
Battery size is set by the fob design, not by the brand overall, and Toyota alone has used several sizes. Common CR1632 users include:
- Some Toyota smart keys, roughly mid-2000s to mid-2010s: Certain smart keys for models such as the Prius, Camry Hybrid, RAV4, and others with Smart Key System use a CR1632. Many other Toyota smart keys from the same period use a CR2032, so check yours.
- Some Lexus smart keys from a similar era.
- Toyota-built shared models such as the Subaru BRZ and Scion FR-S smart keys, which use Toyota-sourced fobs.
- Other devices: Some aftermarket remote-start transmitters, garage remotes, and small electronics also use CR1632.
Toyota remote-head keys (with a metal blade) usually take a CR2016 rather than a CR1632. See our Toyota key fob battery replacement guide and the Lexus key fob battery replacement guide for model details, or check the key fob battery size chart.
CR1632 vs CR1620 vs CR1616 vs CR2032
| Battery | Size | Approx. capacity | Use in a CR1632 fob? |
|---|---|---|---|
| CR1616 | 16 x 1.6 mm | About 50-55 mAh | No; half as thick, poor contact, short life |
| CR1620 | 16 x 2.0 mm | About 70-80 mAh | Emergency only, if contacts still press firmly |
| CR1632 | 16 x 3.2 mm | About 120-140 mAh | Correct fit |
| CR2032 | 20 x 3.2 mm | About 210-240 mAh | No; 4 mm too wide to fit the holder |
Some websites suggest a thinner 16 mm cell as a substitute. That can work for a day or two if the contact spring is strong, but the thinner cell holds far less energy and often loses contact. Use a CR1632. Our CR1620 key fob battery guide covers the thinner size if your fob actually uses that one.
How to Confirm Your Fob Takes a CR1632
- Read the code on the positive (+) face of the old cell.
- Check the owner’s manual under “electronic key,” “smart key,” or “battery.”
- Measure it. About 16 mm wide and 3.2 mm thick is a CR1632.
What You Need
- One CR1632 from a known brand
- A small flat screwdriver or plastic pry tool; tape the tip to avoid scratches
- Access to the mechanical key, which on most smart keys releases the case
CR1632 3V Lithium Coin Battery
Check that the listing says CR1632 (not CR1620 or CR2032) and choose a name brand with a recent date code. CR1632 is less common in stores, so a spare is worth having.
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How to Replace a CR1632 Smart Key Battery
The general process for a Toyota-style smart key looks like this. Your fob may differ, so follow the owner’s manual if it shows another method.
- Slide the release and pull out the mechanical key.
- Find the slot exposed where the key came out. Insert a taped flat screwdriver and twist gently to split the case.
- Lift out the inner module if your key has one, and open it to reach the cell. Some designs have a small cover over the battery.
- Note the polarity before removing the old cell, and follow any marking inside the holder.
- Install the new CR1632 by the edges, matching the orientation.
- Reassemble, reinsert the mechanical key, and test lock, unlock, and push-button start.
Toyota and Lexus smart keys normally keep their registration through a battery change. If the car shows “key not detected” afterward, recheck polarity and contacts, then see car key not detected after battery change.
If Your Smart Key Battery Dies Away From Home
You can usually still start the car. On most Toyota and Lexus push-button models, you hold the smart key logo side against the engine start button while pressing the brake, and the car reads the transponder directly. The mechanical key opens the driver’s door. The exact procedure is in your owner’s manual. If you get stuck with no spare at all, our guide to how to program a key fob explains when a replacement smart key needs a dealer or locksmith.
How Long Does a CR1632 Last in a Smart Key?
Typically about 1.5-3 years. Smart keys listen for the car’s signal constantly, so they use more power than a plain remote. Storing the key near the car, in a hot vehicle, or next to phones and other electronics can shorten life. Many Toyota and Lexus models let you switch the smart key to a battery-saving mode; check your manual for the button sequence.
Signs Your CR1632 Smart Key Battery Is Low
Smart keys usually give warnings before they quit completely. Common signs include:
- A dash message such as “key battery low” or a flashing key indicator.
- Touch-to-unlock door handles responding only on the second or third try.
- “Key not detected” when you press the start button, especially in cold weather.
- Remote buttons working only when you are close to the car.
- The small LED on the fob staying dim or not lighting.
A fresh CR1632 reads about 3.2-3.3V on a multimeter. If yours reads below about 2.9V at rest, replace it. Our key fob battery voltage guide explains the readings, and key fob battery low symptoms covers more warning signs.
Because CR1632 is less common on store racks than the CR2032, keep one sealed spare at home. Store it in its original packaging at room temperature and away from children.
Frequently Asked Questions
No. They share the 3.2 mm thickness, but the CR2032 is 20 mm wide and will not fit a 16 mm holder.
Only briefly in an emergency. The CR1620 is 1.2 mm thinner and holds about half the energy, so contact may be loose and it will die sooner.
Certain Toyota and Lexus smart keys from roughly the mid-2000s to mid-2010s, including some Prius, Camry Hybrid, and RAV4 keys. Many other Toyota smart keys use a CR2032, so read your old battery.
Yes. DL1632 is Duracell’s label and ECR1632 is Energizer’s label for the standard CR1632.
Usually not. Toyota and Lexus smart keys keep their registration. If the car does not detect the key, check battery orientation and contacts first.