JohnnyU from United States, WI Public Profile

If you are looking for a protected 18650 button top with built-in rechargeability (onboard/built-in USB-C) with name brand recognition you have a few choices.

The Streamlight SL-B26 (if you get a recent one in USB-C) at 2600mAh at 70.4mm in length (+/- 0.2mm) from top of button to bottom.

The Surefire SF18650B (which only seems to come in micro-USB) at 3500mAh at 70.4mm in length (+/- 0.2mm) from top of button to bottom.

The Nitecore NL1836R at 3600mAh at 71.1mm in length (+/- 0.2mm) from top of button to bottom.

There are certainly others from what are listed above (Nitecore has a NL1826R at 2600mAh as well with onboard USB-C).

For me, the Surefire being micro-USB is a pain given everything transitioning to USB-C. The newer Streamlight does come with USB but it's a crapshoot if you get one since they didn't change the model number and so micro-USB and USB-C are shipping under the same model number. The Streamlight 18650 form factor is also only 2600mAh (Streamlight's proprietary form factor in higher capacity is ridiculous).

The Nightcore is great but just a BCH longer than others and it may have fitment issues in some older lights or devices. Have tested NL1836R reliably in the Streamlight PolyTac X (note the 'X'), Streamlight ProTac HL-X, and Streamlight ProTac HP-X -- no troubles in any of them.

To those that have had trouble with fitment due to length, try Nitecore (or other OEM) protected button tops that do NOT have the onboard USB. They run often 2 - 2.5mm shor