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    Batteries & Chargers

    Flashlight Batteries & Chargers — CR123A, 18650, 21700 & Smart Chargers from SureFire, Fenix & Nite Core at Knifeworks

    The right battery keeps your flashlight ready when you need it. At Knifeworks, we carry the full spectrum of professional flashlight batteries and chargers: SureFire CR123A lithium primary cells in 2-packs and 12-packs, Fenix and Nite Core 18650 and 21700 rechargeable Li-Ion cells in multiple capacities, Streamlight replacement battery packs for Stinger and Strion duty lights, smart dual and quad chargers from Fenix and Nite Core, and USB-C charging accessories. Everything ships same or next business day from Columbia, Louisiana. Free ground shipping on qualifying orders over $99. Call 888-225-9775 with any questions.

    Compare Selected
    CR123A, 18650, 21700 & Replacement PacksSureFire CR123A primary cells, Fenix and Nite Core 18650 and 21700 rechargeable Li-Ion cells, and Streamlight duty light replacement battery packs — all in stock.
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    SureFire, Fenix, Nite Core & StreamlightThe battery brands that professional flashlight users trust — matched to the lights they power. No generic substitutes.
    Smart Chargers — Dual & Quad ChannelFenix ARE-A2, ARE-X2, and Nite Core Intellicharge i4 — smart chargers that auto-detect cell type, capacity, and charge state for safe, efficient charging.
    Same or Next Business Day ShippingShips from Columbia, Louisiana. Orders before 2PM CST ship same day. Free ground shipping on qualifying orders over $99. Call 888-225-9775.

    The Flashlight Battery & Charger Buyer's Guide (2026)

    Everything you need to buy the right batteries and chargers for your flashlights — primary vs. rechargeable, cell size, capacity, and charger compatibility — explained clearly.

    Battery Type Guide — CR123A vs. 18650 vs. 21700 vs. Replacement Packs＋

    Four battery types cover the Knifeworks battery catalog. Here's how they differ and which flashlights each type powers:

    Battery TypeChemistryRechargeable?PowersBest For
    CR123A LithiumLithium primary (disposable)No — single useSureFire, most tactical flashlights, some Streamlight modelsEmergency kits, duty lights, 10-year shelf life, extreme temperatures
    18650 Li-IonLithium-Ion rechargeableYes — USB or chargerFenix, Nite Core, and most modern rechargeable flashlights and headlampsDaily carry rechargeable lights, outdoor use, highest capacity per dollar
    21700 Li-IonLithium-Ion rechargeableYes — USB or chargerHigh-output Fenix models (PD40R, etc.) requiring higher capacity cellsMaximum output lights that need higher cell capacity than 18650
    Streamlight Replacement PacksNiMH or Li-Ion proprietaryYes — dock or AC chargerStreamlight Stinger, Stinger DS, Strion duty lightsReplacing aging battery packs in Streamlight duty lights
    Match Battery to Light — Don't SubstituteCheck your flashlight's manual or product listing for the exact battery specification before ordering. Using a higher-capacity cell in a light not designed for it can cause overheating or damage. 18650 and 21700 cells are physically different sizes — they are not interchangeable. CR123A and RCR123A (rechargeable) are the same size but different chemistry — check light compatibility before using rechargeable CR123A in a light designed for primary cells.
    CR123A Battery Guide — SureFire vs. Tenergy vs. Nite Core RCR123A＋

    Three CR123A options cover the catalog. Here's how they compare:

    ProductTypePack SizeBest ForPrice
    SureFire SF2-CBCR123A Lithium Primary2-packSingle purchase, trying CR123A, carrying 2 spares$6.99
    SureFire SF12-BBCR123A Lithium Primary12-packStocking up, duty use, bulk purchase discount$28.99
    Tenergy Propel CR123A 12-packCR123A Lithium Primary12-packBudget-conscious bulk CR123A purchase$24.95
    Nite Core RCR123A 650mAhRCR123A Rechargeable Li-IonSingle cellLights compatible with rechargeable CR123A — check compatibility first$7.99

    SureFire CR123A cells are the professional standard — made for SureFire lights but compatible with any CR123A flashlight. They deliver consistent voltage, perform in extreme temperatures (-40°F to 140°F), and have a 10-year shelf life. The 12-pack at $28.99 is the best value for regular users. The Tenergy 12-pack at $24.95 is a practical budget alternative. The Nite Core RCR123A is a rechargeable option for lights specifically listed as RCR123A-compatible — do not use in lights that specify primary CR123A only.

    Buy the 12-PackIf you use CR123A lights regularly — SureFire, tactical flashlights, some Streamlight models — the 12-pack is always the better value. CR123A cells have a 10-year shelf life, so there's no waste in stocking up. SureFire SF12-BB at $28.99 works out to $2.42 per cell vs. $3.50 for the 2-pack.
    18650 Battery Guide — Fenix vs. Nite Core — Capacity, mAh & Which to Buy＋

    18650 is the most common rechargeable flashlight cell size. Higher mAh means longer runtime between charges — here's how the catalog options compare:

    CellCapacityChargingBest ForPrice
    Fenix ARB-L18-3500U3,500 mAhBuilt-in USB-CMaximum runtime in 18650 lights — charges without removing the cell$26.99
    Fenix ARBL18 High-Capacity 3500mAh3,500 mAhExternal chargerHigh capacity cell for charger-based charging setups$24.99
    Fenix ARB-L18-2600U2,600 mAhBuilt-in USB-CStandard capacity rechargeable, USB-C convenient charging$15.99
    Fenix ARB-L18-26002,600 mAhExternal chargerStandard capacity cell for charger-based setups, budget option$10.95
    Nite Core 18650 2600mAh2,600 mAhExternal chargerNite Core light compatibility, standard capacity$15.95

    The Fenix ARB-L18-3500U at $26.99 is the best 18650 cell in the catalog for most buyers — 3,500 mAh for maximum runtime, built-in USB-C charging port so you never need a separate charger, and Fenix's protection circuit to prevent overcharge, over-discharge, and short circuit. If you already have a smart charger and prefer to charge cells externally, the standard Fenix ARBL18 3500mAh at $24.99 delivers the same capacity at a slightly lower price.

    USB-C Built-In vs. External Charger — Which Is Better?Built-in USB-C cells (Fenix ARB-L18-3500U, ARB-L18-2600U) are the more convenient daily carry option — charge directly from any USB-C source without a separate charger. External charger setups are better if you rotate multiple cells and want to charge several simultaneously in a smart charger. For most buyers with one or two lights, built-in USB-C wins on convenience.
    Smart Charger Guide — Fenix ARE-A2, ARE-X2 & Nite Core Intellicharge i4＋

    Smart chargers auto-detect cell type and capacity for safe, efficient charging. Here's how the three charger options compare:

    ChargerChannelsCompatible CellsBest ForPrice
    Fenix ARE-A22-channel (dual)18650, 26650, and other Li-IonTwo-cell charging, standard home and travel use$24.95
    Fenix ARE-X22-channel (dual)18650, 21700, 26650, Li-Ion and NiMHUniversal dual charger — wider cell compatibility including 21700$19.95
    Nite Core Intellicharge i44-channel (quad)Li-Ion, NiMH, NiCd — multiple formatsCharging 4 cells simultaneously, mixed cell type households$26.50
    Tenergy TN270 Li-ion Fast Charger2-channel18650, 26650 Li-IonFast charging option, budget price point$14.95
    Streamlight 18650 Charger Kit2-channel18650 Li-Ion + includes 2 cellsAll-in-one charger and cell kit for Streamlight 18650 lights$42.95
    Which Charger to Buy?For most buyers with Fenix lights running 18650 cells: the Fenix ARE-X2 at $19.95 is the best value — dual channel, wider cell compatibility including 21700, and priced lowest among the smart chargers. For households with 4+ cells to charge simultaneously: the Nite Core Intellicharge i4 at $26.50 is the practical upgrade. The Streamlight kit at $42.95 is purpose-built for Streamlight 18650 light users who need cells and charger together.
    Streamlight Replacement Battery Packs — Stinger, Stinger DS & Strion＋

    Streamlight duty lights use proprietary battery packs — not standard 18650 or CR123A cells. When your Stinger or Strion dims and won't hold charge, the replacement pack is the fix. Here's what's in the catalog:

    ProductCompatible LightChemistryPrice
    Streamlight Stinger NiMH Replacement Battery StickStinger (original)NiMH$21.99
    Streamlight 78105 Battery PackStinger DS — includes carrier and 2 SL cellsLi-Ion (SL cells)$42.99
    Streamlight Stinger Rechargeable Lithium IonStinger series Li-Ion compatibleLi-Ion$29.99
    Streamlight Strion Replacement BatteryStrion seriesLi-Ion$32.99
    How to Know When to Replace a Streamlight Battery PackStreamlight battery packs typically need replacement after 2–3 years of regular duty use. Signs: the light dims sooner after a full charge than it used to, the light won't hold a full charge even after conditioning, or the pack feels warm even on a light charging session. Replacing the pack at the first sign of degradation is far cheaper than replacing the entire light.
    Battery Storage, Safety & Shelf Life — What You Need to Know＋
    • CR123A Lithium Primary: 10-year shelf life at room temperature. Store in a cool, dry location — not in a hot car or freezer. No charging required; dispose after use per local battery disposal regulations.
    • 18650 Li-Ion Rechargeable: Self-discharge at ~2–3% per month when stored. For long-term storage (emergency kits, spare cells), store at 40–60% charge level — not full, not empty. Check and top up every 3–6 months. Store at room temperature, not in heat.
    • 21700 Li-Ion: Same storage principles as 18650 — 40–60% charge for long-term storage, room temperature, check periodically.
    • Never mix old and new cells: In lights that take multiple cells (2x CR123A, 2x 18650), never mix old and new cells in the same light. Mismatched cells can cause voltage imbalance, overheating, and damage to the light.
    • Use a protection circuit: Quality 18650 cells (Fenix, Nite Core) include a built-in protection circuit (PCB) that prevents overcharge, over-discharge, and short circuit. Avoid unprotected cells in lights that don't have built-in protection.
    • Damaged cell disposal: Never use a dented, punctured, or leaking Li-Ion cell. Dispose at a battery recycling location — do not put Li-Ion in household trash.
    Emergency Kit Battery RuleCR123A primary cells for any light in your emergency kit or go-bag. Li-Ion cells self-discharge over months — a rechargeable light in an emergency kit may have a dead battery when you reach for it. CR123A cells are ready after 10 years in storage. Replace annually regardless of use to maintain peak performance.
    Battery & Charger Quick Reference — Find What You Need in 30 Seconds＋
    I need…Best ChoicePriceKey Spec
    CR123A for a SureFire or tactical lightSureFire SF12-BB 12-pack$28.99$2.42/cell, 10-year shelf life, professional standard
    CR123A budget bulk purchaseTenergy Propel 12-pack$24.95$2.08/cell, good value for non-duty applications
    18650 with built-in USB-C (max capacity)Fenix ARB-L18-3500U$26.993,500 mAh, USB-C built-in, no separate charger needed
    18650 for external charger setupFenix ARB-L18-2600 or ARBL18 3500mAh$10.95–$24.99Standard or high capacity, charger-compatible
    21700 Li-Ion cellFenix L215000 USB 21700$26.955,000 mAh, USB rechargeable, for compatible Fenix lights
    Smart dual charger (best value)Fenix ARE-X2$19.95Dual channel, 18650 + 21700 + NiMH compatible
    Smart quad chargerNite Core Intellicharge i4$26.504 cells simultaneously, mixed cell types
    Streamlight Stinger replacement packStreamlight Stinger NiMH or Li-Ion$21.99–$42.99Match to your specific Stinger model
    Streamlight Strion replacement batteryStreamlight Strion Replacement Battery$32.99Li-Ion, Strion series compatible
    Not Sure What Your Light Takes?Call 888-225-9775 — our team can identify the right battery or replacement pack for any Streamlight, Fenix, Nite Core, or SureFire light in your kit.

    Flashlight Batteries & Chargers: Frequently Asked Questions

    Answered by the Knifeworks team — we stock and use these batteries in our own lights.

    What is the best CR123A battery to buy?＋

    For SureFire lights and any professional or duty flashlight, SureFire SF12-BB at $28.99 for a 12-pack is the standard — $2.42 per cell, consistent performance, 10-year shelf life, and rated for extreme temperatures. For non-duty applications where you want CR123A at a lower cost, the Tenergy Propel 12-pack at $24.95 is a practical budget alternative. If you only need 2 cells for an emergency kit or to try CR123A, the SureFire SF2-CB 2-pack at $6.99 is the entry point. Buy the 12-pack if you use CR123A lights regularly — the shelf life means no waste.

    What is the best 18650 battery for a Fenix flashlight?＋

    For most Fenix lights, the Fenix ARB-L18-3500U at $26.99 is the best choice — 3,500 mAh for maximum runtime and built-in USB-C charging so you never need a separate charger. If you already have a smart charger and prefer to charge cells externally, the Fenix ARBL18 3500mAh at $24.99 delivers the same capacity at a slightly lower price. For lights where 2,600 mAh is sufficient and you want a lower-cost option, the Fenix ARB-L18-2600 at $10.95 is a practical budget 18650. Always check your specific Fenix light model's battery specification before ordering.

    What is the difference between 18650 and 21700 batteries?＋

    18650 and 21700 are different physical sizes — they are not interchangeable. The 18650 is 18mm diameter × 65mm length; the 21700 is 21mm diameter × 70mm length. 21700 cells are physically larger and typically hold more capacity (4,000–5,000 mAh vs. 2,600–3,500 mAh for 18650). The Fenix L215000 21700 in the catalog holds 5,000 mAh. Only use the cell size your specific light is designed for — check your light's product listing or manual. Most lights are built for one size or the other, not both.

    Do I need a smart charger for 18650 batteries?＋

    For cells with built-in USB-C charging (Fenix ARB-L18-3500U, ARB-L18-2600U), you don't need a separate charger — plug into any USB-C source. For cells without built-in charging, a smart charger is strongly recommended over cheap chargers or charging via the light itself. Smart chargers like the Fenix ARE-X2 ($19.95) and Nite Core Intellicharge i4 ($26.50) auto-detect cell chemistry and charge state, preventing overcharge and extending cell life. The Fenix ARE-X2 at $19.95 is the best-value entry point for an external smart charger in the catalog.

    What replacement battery does the Streamlight Stinger use?＋

    The original Streamlight Stinger uses the NiMH Replacement Battery Stick at $21.99. The Stinger DS and newer Stinger models use the 78105 Battery Pack at $42.99 (includes carrier and 2 SL cells) or the Li-Ion Stinger Rechargeable at $29.99. The Strion series uses the Strion Replacement Battery at $32.99. Always verify your specific Streamlight model before ordering — the Stinger, Stinger DS, Stinger LED, and Strion lines use different battery packs. Call 888-225-9775 if you need help identifying your light's replacement battery.

    How long do CR123A batteries last in storage?＋

    SureFire CR123A lithium batteries have a 10-year shelf life when stored at room temperature in a dry location. This makes them the ideal battery for emergency kits, go-bags, and vehicle emergency lights — you can buy a 12-pack today, put it away, and have working batteries a decade later. The 10-year rating applies to storage; in active use the runtime depends on the specific light and output mode. Do not store CR123A batteries in extreme heat (hot car) or freeze them — room temperature storage is optimal.

    Can I use rechargeable CR123A (RCR123A) batteries in my SureFire?＋

    Only in SureFire lights specifically listed as RCR123A-compatible. RCR123A cells have a higher voltage (3.7V) than standard CR123A primary cells (3.0V) — using an RCR123A in a light designed for primary CR123A only can damage the light or LED driver. SureFire publishes compatibility information for their specific light models. When in doubt, use primary CR123A cells. Call 888-225-9775 if you're unsure about your specific SureFire model's rechargeable cell compatibility.

    What is free shipping at Knifeworks?＋

    Knifeworks offers free ground shipping on qualifying orders over $99 to the 48 contiguous United States. Orders placed before 2PM CST ship same business day from Columbia, Louisiana. Call 888-225-9775 for questions about a specific order or shipping timeline.

    SureFire CR123A · Fenix 18650 · Nite Core 18650 · Smart Chargers · Streamlight Replacement Packs · Free Shipping Over $99

    Flashlight Batteries & Chargers — In Stock and Ready to Ship from Columbia, Louisiana

    Knifeworks carries SureFire CR123A cells, Fenix and Nite Core 18650 and 21700 rechargeable cells, smart chargers, Streamlight duty light replacement packs, and USB-C charging accessories. Free ground shipping on qualifying orders over $99. Questions? Call 888-225-9775 — we use these batteries in our own lights.

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