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Views: 1 Author: Site Editor Publish Time: 2025-04-02 Origin: Site
AG1 and AG4 are small button cell batteries that look similar but differ in thickness, capacity, and lifespan. Below is a detailed comparison to help you understand their differences and choose the right one for your device.
| Feature | AG1 (364) | AG4 (377) |
|---|---|---|
| Size | Diameter: 6.8mm Thickness: 2.1mm | Diameter: 6.8mm Thickness: 2.6mm |
| Voltage | 1.5V | 1.5V |
| Battery Chemistry | Alkaline (LR621) / Silver Oxide (SR621) | Alkaline (LR626) / Silver Oxide (SR626) |
| Capacity (mAh) | Alkaline: 12-15mAh Silver Oxide: 20-25mAh | Alkaline: 15-18mAh Silver Oxide: 28-32mAh |
| Discharge Characteristics | Alkaline: Voltage drops quickly Silver Oxide: More stable voltage | Alkaline: Voltage drops quickly Silver Oxide: More stable voltage |
| Lifespan | Shorter – drains faster | Longer – lasts longer due to higher capacity |
| Common Uses | Watches, calculators, small remotes, LED lights | Watches, medical devices, small toys, hearing aids |
| Alternative Names | 364, LR621, SR621, GP364, V364 | 377, LR626, SR626, GP377, V377 |
| Weight | ~0.3g | ~0.4g |
| Shelf Life | Alkaline: ~2-3 years Silver Oxide: ~4-6 years | Alkaline: ~2-3 years Silver Oxide: ~4-6 years |
| Price | Usually cheaper | Slightly more expensive due to higher capacity |
| Leakage Risk | Higher for alkaline batteries | Lower for silver oxide batteries |
The diameter of AG1 and AG4 is the same (6.8mm), but AG4 is 0.5mm thicker.
If your device has a tight battery compartment, AG4 might not fit properly in place of AG1.
Some devices can use AG4 instead of AG1, but you should check the battery slot first.
AG4 has a higher capacity, especially in silver oxide (SR626) versions.
AG1 (SR621) has 20-25mAh, while AG4 (SR626) has 28-32mAh – about 30% more energy.
Alkaline versions have lower capacity and drain faster, making them less ideal for long-term use.
Bottom Line: If you want a longer battery life, go with AG4 (especially the silver oxide version).
Alkaline batteries (LR621, LR626) start at 1.5V, but their voltage drops quickly as they discharge. This can cause some devices (like watches) to lose accuracy.
Silver Oxide batteries (SR621, SR626) provide a more stable voltage for a longer period, making them better for devices that require consistent power.
Tip: If you are using a watch, medical device, or anything that needs a stable power source, choose silver oxide over alkaline.
Alkaline batteries have a higher risk of leaking, especially if left unused for long periods.
Silver Oxide batteries are more resistant to leakage, making them a safer choice for expensive devices.
Best Practice: If you’re storing batteries for future use, silver oxide (SR) batteries are a better option.
Alkaline AG1/AG4: Usually 2-3 years before performance starts to decline.
Silver Oxide AG1/AG4: Can last 4-6 years when stored properly.
Tip: If you don’t use your device often, silver oxide batteries are better because they last longer in storage.
| If you need… | Go for… |
|---|---|
| A battery for ultra-thin devices | AG1 (364) (thinner) |
| A longer-lasting battery | AG4 (377) (higher capacity) |
| A battery for watches | AG4 Silver Oxide (SR626) (stable voltage) |
| A cheaper option | AG1 Alkaline (LR621) |
| A battery with low leakage risk | AG4 Silver Oxide (SR626) |
| A battery for toys & calculators | Either one works, but AG4 lasts longer |
Final Tip: Always check your device manual to ensure you’re using the right battery! If your device can fit AG4, it’s usually the better choice.
