Sombrero 400909-40mAh High Capacity Rechargeable Battery: Long-lasting power
Available Options
Give your smartwatch the juice it craves with this high-capacity rechargeable battery. Built to last (unlike your patience when your watch dies mid-workout), it keeps your gadget going longer, so you're not constantly hunting for a charger. Ideal for anyone who thinks 'low battery' is the ultimate buzzkill.
- Packs a 3.7V punch to keep your device running smoothly—no lag, no drama.
- With a 400909-40mAh capacity, it's like the Energizer Bunny for your wrist; it just keeps going.
- Fits more smartwatches than you can name, making it the universal donor of the tech world.
- 3.7V output
- Compatible with smartwatches
- 400909-40mAh capacity
- Long-lasting power
General specs
- Brand: Sombrero
- Model: 400909-40mAh
- Seller: Joom
- Voltage: 3.7V
- Capacity: 400909-40mAh
- Compatibility: Smartwatches
- First listed by seller: 5/23/25
If you are interested in more details, you can find full information on the seller's page.
Shipping options
United States
Comparison with similar products
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Sombrero 400909-40mAh Long-lasting power
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SACOSDING Smart Watch 650 mAh battery
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| Brand | Sombrero | CLOUD Phone Acc | Quhgahfa | Bunny House | 3d printing machine | SACOSDING |
| Model | 400909-40mAh | EB BR720ABE | Smart Watch | |||
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| Rating |
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| Price | $7.31 | $9.57 | $4.77 | $5.33 | $11.36 | $59.74 |
| Seller | Joom | Joom | Joom | Joom | Joom | Joom |
| Update | August 27, 2025 | August 18, 2025 | August 20, 2025 | August 20, 2025 | August 29, 2025 | August 8, 2025 |
| Voltage | 3.7V | 3.7V | 3.7V | |||
| Capacity | 400909-40mAh | 380 mAh | 250 mAh | |||
| Compatibility | Smartwatches | A1, DZ09, RYX-NX9, KSW-S6 | Smartwatches, Bluetooth headsets | Smartwatches, Bluetooth headsets | Samsung Gear S2 Classic SM R720, Samsung Gear S2 Classic SM R732 | |
High Capacity Rechargeable Battery
Zoé M.
Strasbourg
June 4, 2025
I bought this as a gift for my husband after his old battery kept dying mid-day—it was such a hassle, especially during workouts or concerts. This Sombrero battery solved that problem beautifully; it holds a charge for ages and keeps everything running smoothly. The only downside is the warmth, but it's a small trade-off for the convenience. Overall, it's a great solution that I'd recommend to anyone tired of constant charging.
- Pros: This battery is incredibly long-lasting, keeping my smartwatch powered through long days without needing a charge, which is perfect for my busy schedule. It fits my device well and delivers steady power with no interruptions, making it reliable for daily use.
- Cons: From what I feel, it gets a bit warm during extended use, which can be a minor annoyance, and while it works with many watches, it might not be a perfect fit for every model out there.