Vapcell F38 18650, 10 Amp, 3800mAh, Button Top

Please keep in mind that the capacity you'll get will depend on the current/amps of the torch and the selected brightness level. For example, the Convoy C8+ SFT40 requires 8 amps on turbo mode, so if you plan on using turbo a lot then you'll see a significant reduction in capacity over the lower brightness modes.
 
A battery's voltage will sag the higher the load that is applied, so for torches using greater than 6 amps of continuous turbo use, I'd be grabbing the Molicel P30B which is a lower capacity battery but higher amps, higher amps reduces the voltage sag under load. It's all about finding the best capacity vs current balance for the torch.
 
Price is per battery
 
Specs:

- Model: F38
- Brand: Vapcell
- Typical capacity: 3800mAh (0.2C discharge)
- Minimum capacity: 3650 mAh (0.2C discharge)
- Nominal voltage: 3.6V
- Charging voltage: 4.20V
- Discharging end voltage: 2.5V
- Standard charging current: 1A
- Maximum charging current: 2.5A
- Max continuous discharging current: 10A
- Max discharge current: 12.5A (with 60 °C temperature cut-off）
- Size: 18.3mm x 67.1mm
- Weight: 48g (approx)
 
Buyers must be aware of lithium safety before purchase. Please read my thorough battery safety guide - here