{"product_id":"delipow-4000mah-21700-battery-40a-rechargeable-battery-with-flat-top-3-6v-lithium-widely-compatible-led-flashlights-emergency-lights-portable-devices-headlights-toys-remote-controls-etc","title":"Delipow 4000mAh 3.6V 21700 Rechargeable Battery – High Drain Max 40A Flat Top for Turbo Flashlights, RC Models \u0026 Power Tools","description":"\u003ch2\u003e\u003cspan class=\"\"\u003ePure Flat‑Top Power for Extreme Current Demands\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan class=\"\"\u003eWhen your gear demands instantaneous high current — a turbo flashlight blasting lumens, an RC truggy exploding out of a corner, or a cordless impact driver driving screws into hardwood — the\u003cspan\u003e \u003c\/span\u003e\u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eDelipow 4000mAh 21700 battery\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003edelivers without hesitation. Engineered with a single, no‑compromise flat‑top design, this cell is purpose‑built for the tightest battery tubes, the most demanding pogo‑pin contacts, and the custom spot‑welded packs of serious enthusiasts. It is rated for\u003cspan\u003e \u003c\/span\u003e\u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e30A continuous discharge\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003ewith a\u003cspan\u003e \u003c\/span\u003e\u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e40A max pulse\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e, all while storing a genuine\u003cspan\u003e \u003c\/span\u003e\u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e4000mAh\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eof energy (approximately 14.4 watt‑hours at 3.6V nominal). This is the sweet spot for users who need high‑drain performance without sacrificing meaningful runtime.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003e\u003cspan class=\"\"\u003eUnprotected, Flat‑Top — Why It Matters\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan class=\"\"\u003eThe Delipow 21700 comes as an unprotected bare cell with a completely flush positive terminal. We intentionally omit the external protection PCB to keep the overall length at the industry‑standard 70.0mm — critical for fitting into precisely machined flashlight tubes, compact power tool battery shells, and densely packed RC battery trays. Removing the PCB also eliminates the added internal resistance that can choke current flow during high‑drain pulses, ensuring your devices get every last amp they demand. The flat‑top terminal is the universal standard for high‑performance devices: it mates perfectly with pogo‑pin contacts, recessed flat PCB pads, and nickel strip spot welds without the added height of a button top that can prevent caps from closing or cause intermittent contact. Naturally, this design requires you to use a quality charger with precise 4.2V termination and to only install the cell in devices that have their own low‑voltage cutoff — a feature already present in virtually all modern turbo flashlights, brushless RC ESCs, and power tool motor controllers.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003e\u003cspan class=\"\"\u003eWhere the Delipow 40A Flat‑Top Cell Excels\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan class=\"\"\u003eIn a FET‑driven turbo flashlight (Emisar D4SV2, Noctigon K1, custom SBT90.2 builds), the Delipow 4000mAh flat‑top cell delivers the instantaneous 20–30A surges needed to keep the LEDs at full blaze without triggering early step‑down. Its flush terminal ensures a perfect fit in the ultra‑tight battery tubes typical of these lights. In a 1\/10 scale RC truggy or monster truck, a 2S or 3S pack built from these cells provides relentless punch off the line and strong mid‑range torque that lasts an entire heat — and the flat tops weld cleanly into stick or saddle packs. For cordless power tools — drills, impact drivers, mini circular saws — the high discharge rate prevents motor stalling under load, while the 4000mAh capacity lets you drive dozens of screws or make numerous cuts before reaching for the charger. The flat‑top design is also the standard for rebuilding 18V\/20V tool batteries, where cells are spot‑welded in series.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003e\u003cspan class=\"\"\u003eSafety and Longevity Without the PCB\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cspan class=\"\"\u003eDelipow's advanced NMC (Nickel‑Manganese‑Cobalt) chemistry provides a flat 3.6V nominal discharge curve, excellent thermal stability, and an impressive cycle life. The cell is rated for over\u003cspan\u003e \u003c\/span\u003e\u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e500 full charge\/discharge cycles\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003ewhile retaining at least 70% of its original capacity. Low self‑discharge means a spare pack stored at 3.6–3.7V will be ready months later. Built‑in passive safety layers include a\u003cspan\u003e \u003c\/span\u003e\u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003ePTC thermistor\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003ethat increases resistance during over‑current, a\u003cspan\u003e \u003c\/span\u003e\u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eresealable safety vent\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003ethat releases gas if internal pressure builds dangerously, and a\u003cspan\u003e \u003c\/span\u003e\u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eCID (Current Interrupt Device)\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003ethat physically disconnects the internal electrode under extreme pressure. The rugged nickel‑plated steel can withstands drops, vibrations, and the temperature swings typical of power tools and outdoor RC use.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003ch2\u003e\u003cspan class=\"\"\u003eKey Features\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eExtreme High‑Drain Output: 30A Continuous \/ 40A Pulse\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eFeeds the most demanding turbo flashlights, RC models, and power tools without voltage sag. 30A continuous keeps devices at full power; 40A pulse handles instantaneous startup surges.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eGenuine 4000mAh Capacity (14.4Wh)\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eProvides useful runtime even in high‑current applications — about 10–15 minutes of continuous turbo in a flashlight, multiple RC heats, or dozens of tool operations per charge.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eUnprotected Flat‑Top Design — The Enthusiast Standard\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eFlush positive terminal ensures a perfect fit in ultra‑tight flashlight tubes, recessed contacts, and spot‑welded packs. Eliminates the added length and resistance of a protection PCB. Requires a 4.2V Li‑ion charger and device with low‑voltage cutoff.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eStable NMC Chemistry \u0026amp; Flat Discharge\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eMaintains a consistent 3.6V nominal voltage with minimal sag. Light output, motor RPM, and tool torque stay predictable from fresh off the charger to nearly empty.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eUltra‑Low Internal Resistance (≤18mΩ)\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eVoltage drop at 30A is only ~0.54V. Keeps heat generation low and devices in regulation longer.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e500+ Cycle Life \u0026amp; Low Self‑Discharge\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eRecharge over 500 times with minimal capacity fade. Stores for months at ~3.6–3.7V, always ready for the next race, project, or outage.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eMulti‑Layered Passive Safety\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eBuilt‑in PTC thermistor, resealable vent, and CID protect against over‑current, over‑pressure, and short circuits.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eRugged Nickel‑Plated Steel Can\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eCorrosion‑resistant and impact‑resistant. Withstands the vibrations, drops, and harsh conditions of power tools, RC vehicles, and outdoor use.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003ch2\u003e\u003cspan class=\"\"\u003eTechnical Parameters\u003c\/span\u003e\u003c\/h2\u003e\n\u003cdiv class=\"ds-scroll-area ds-scroll-area--show-on-focus-within ds-scroll-area--enabled _1210dd7 c03cafe9\"\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cspan class=\"\"\u003eParameter\u003c\/span\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cspan class=\"\"\u003eSpecification\u003c\/span\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eBattery Model\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eDelipow 21700 4000mAh High Drain\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eBattery Type\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e21700 Li‑ion (unprotected, bare cell)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eNominal Capacity\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e4000mAh (14.4Wh at 3.6V)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eNominal Voltage\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e3.6V (also commonly labeled 3.7V)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eFull Charge Voltage\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e4.2V ± 0.05V\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eDischarge Cut‑off Voltage\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e2.5V (use only with low‑voltage protected devices)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eStandard Charge Current\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e2.0A (0.5C)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eMax Charge Current\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e4.0A (1C)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eMax Continuous Discharge\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e30A (7.5C) — sustained high drain\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eMax Pulse Discharge\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e40A (\u0026lt;5 seconds)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eInternal Resistance\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e≤18mΩ (AC 1kHz, bare cell)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eProtection Circuit\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eNone — requires external over‑discharge protection\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003ePositive Terminal\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eFlat Top (flush) — no raised nipple\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eDimensions\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eApprox. 21.2mm dia. × 70.0mm length\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eWeight\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eApprox. 68g\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eCycle Life\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e≥500 cycles (≥70% initial capacity at 0.5C charge\/discharge)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eOperating Temp. (Charge)\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e0°C to 45°C\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eOperating Temp. (Discharge)\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e-20°C to 75°C\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eStorage Temp. \u0026amp; Humidity\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e-5°C to 35°C, \u0026lt;75% RH (recommend 3.6–3.7V storage)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eChemistry\u003c\/span\u003e\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eNMC (Lithium Nickel Manganese Cobalt Oxide)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003chr\u003e\n\u003ch2\u003e\u003cspan class=\"\"\u003eApplications\u003c\/span\u003e\u003c\/h2\u003e\n\u003col start=\"1\"\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eTurbo Flashlights \u0026amp; High‑Lumen Hot‑Rods\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eFor flashlights pulling 15–30A on turbo — Emisar D4SV2, Noctigon KR1\/K1, Fireflies, and custom FET‑driven builds — this flat‑top cell delivers the instantaneous current needed for maximum brightness without premature step‑down. The flush terminal ensures a perfect fit in the tightest battery tubes where button tops simply will not fit.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eRC Cars, Trucks \u0026amp; Drones\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eBuild a 2S or 3S Li‑ion pack for 1\/10 and 1\/8 scale vehicles. The 30A continuous discharge feeds brushless motors with relentless punch, while the flat‑top design allows clean, low‑profile spot welds for stick packs, saddle packs, and drone battery builds.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eCordless Power Tools\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eReplace worn‑out cells in drills, impact drivers, circular saws, and angle grinders. The high drain rate handles the startup spikes and heavy loads of professional tools, and the flat‑top terminal is the standard for welding into 5S1P or 5S2P configurations for 18V\/20V platforms.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eHigh‑Power Portable Fans \u0026amp; Cooling Devices\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eLarge portable fans that draw 3–8A on high speed run powerfully and consistently with this cell. The flat top mates seamlessly with recessed contacts in many high‑output fan battery bays.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eDIY High‑Current Power Banks \u0026amp; Inverters\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eBuild a portable power station or high‑current power bank that can fast‑charge multiple devices. The flat‑top cell is ready for spot welding into series\/parallel configurations without the interference of a button top.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eProfessional \u0026amp; Industrial Equipment\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003ePortable barcode scanners, thermal printers, and medical devices that require both high current pulses and dependable runtime are well‑served by this flat‑top 4000mAh cell.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003chr\u003e\n\u003ch2\u003e\u003cspan class=\"\"\u003eFAQ\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ1: Is this cell really capable of 40A? I see 30A continuous and 40A max.\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eA: Yes. The cell is rated for\u003cspan\u003e \u003c\/span\u003e\u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e30A continuous discharge\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003eand can safely pulse up to\u003cspan\u003e \u003c\/span\u003e\u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e40A\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e\u003cspan\u003e \u003c\/span\u003efor short bursts (under 5 seconds). We specify both figures so you know exactly what to expect. For applications that demand sustained 40A+, consider ultra‑high‑rate cells like the Samsung 30T or Molicel P42A.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ2: Why is the battery unprotected and only available in flat top?\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eA: Delipow designed this cell specifically for high‑drain applications where a protection PCB would add unwanted length and resistance, and where a button top would prevent installation in tight compartments or interfere with spot welding. The flat top is the universal standard for enthusiast flashlights, power tool rebuilds, and custom battery packs. It's completely safe when you use a quality 4.2V Li‑ion charger and only install it in devices with built‑in low‑voltage cutoff. The cell's PTC, vent, and CID provide passive safety.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ3: Will this flat‑top cell work in my flashlight if it originally had a button‑top battery?\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eA: It depends on the light. If your flashlight uses a spring‑loaded positive contact with a physical reverse‑polarity ring, a button top may be required to make contact. However, most high‑performance and enthusiast flashlights are designed specifically for flat‑top cells, as they offer lower resistance and a more compact fit. Check your device manual: if it specifies \"flat top\" or \"unprotected flat top,\" this cell will work perfectly. If the light has a mechanical polarity ring and the flat top doesn't reach, you may need a button‑top cell instead.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ4: Can I use this in a device that takes 18650 batteries?\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eA: No. A 21700 cell (21mm × 70mm) is physically larger than an 18650 (18mm × 65mm). Your device must explicitly support the 21700 form factor. Do not force a 21700 into an 18650 tube.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ5: How does the 3.6V nominal voltage compare to 3.7V cells?\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eA: 3.6V and 3.7V are often used interchangeably for lithium‑ion cells; the actual voltage depends on the specific chemistry and manufacturer rating. This cell is fully compatible with all 3.7V nominal devices. You charge it to 4.2V and discharge to 2.5V, just like any standard Li‑ion cell.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ6: How hot does the cell get at 30A continuous?\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eA: With ≤18mΩ internal resistance, heat generation is moderate. The cell will become warm — typically reaching 60–70°C after several minutes of sustained 30A — but stays within safe limits. Allow cooling between heavy discharge runs for best longevity.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ7: Can I charge this battery at 4A?\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eA: Yes, 4A (1C) is the maximum charge current. For maximum cycle life, we recommend the standard 2A (0.5C) charge rate. Faster charging generates more heat and may slightly reduce long‑term capacity.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ8: How should I store spare cells?\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eA: In a plastic case or silicone sleeve, away from metal and moisture. For storage over one month, bring the voltage to ~3.6–3.7V (about 50% charge). Check every 3 months and recharge if below 3.0V. Never store fully depleted.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ9: Can I fly with this battery?\u003c\/span\u003e\u003c\/strong\u003e\u003cbr\u003e\u003cspan class=\"\"\u003eA: Yes. At ~14.4Wh, it's well under the 100Wh IATA limit. Carry in hand luggage with terminals insulated.\u003c\/span\u003e\u003c\/p\u003e","brand":"DELIPOW","offers":[{"title":"Default Title","offer_id":51454094344438,"sku":"OAS170","price":6.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/2753\/6886\/files\/delipow-21700-4000mAh-40A-flat-top-main_fcbcb541-98f6-4c34-a0f5-6d3d0d8e352c.webp?v=1786965248","url":"https:\/\/oneandes.com\/products\/delipow-4000mah-21700-battery-40a-rechargeable-battery-with-flat-top-3-6v-lithium-widely-compatible-led-flashlights-emergency-lights-portable-devices-headlights-toys-remote-controls-etc","provider":"OneAndes","version":"1.0","type":"link"}