army gear 1000 lumen viper rechargeable tactical flashlight 2-pack LED High Lumens, Mini LED Flashlight 2 Pack, 5 Modes Zoomable Beam, Battery Powered (Batteries Not Included) for Camping, Hunting, Home & Emergency, Compact Small LED Flashlight Victoper VT-FLV1000 2 Pack Tactical

So far I have only worked with the Eneloop Pro, but likely will stock up on some standard Eneloops for lower-drain lights for longer-term use around the house

Like the TK and other PD series flashlights, Fenix allows you to use your own batteries, so long as they are button tops

I have no evidence of this

Advantages and disadvantages of rechargeable batteries (secondary cells) Advantages Rechargeable, making them significantly cheaper in continuous operation Suitable for devices with high power consumption LSD NiMH batteries have significantly lower self-discharge than standard NiMH batteries Li-ion batteries offer very high energy density in a compact design Disadvantages Slightly higher self-discharge than batteries, therefore regular recharging is necessary Require a suitable charger Sensitive to deep discharge, overcharging, and extreme heat Nominal voltage of 1.2 V (for NiMH) may in rare cases limit the function of individual devices Higher initial costs (purchase costs), which only pay off over time In detail: Differences between rechargeable batteries and regular batteries Power storage devices in the widely used AAA or AA format are available as rechargeable batteries or disposable batteries