{"product_id":"2-pack-eve-21700-lithium-battery-40p-power-50a-discharge-lithium-battery-with-flat-top-for-drone-tool-electric-car","title":"2-Pack EVE 21700-40P 4000mAh 3.7V Flat Top Battery – 35A Continuous \/ 40A Pulse for Drones, Power Tools \u0026 RC Cars","description":"\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eDouble the Power, Double the Endurance\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eThis 2‑pack of EVE 21700‑40P cells delivers the ultimate high‑drain solution for your most demanding devices. Each cell combines a genuine \u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e4000mAh capacity\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e with a ferocious \u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e35A continuous discharge\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e and the ability to \u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003epulse up to 40A\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e for instantaneous surges. Whether you’re building a high‑performance FPV drone pack, rebuilding a cordless drill battery, or powering a 1\/8 scale RC truggy, these flat‑top cells provide the relentless current and meaningful runtime that ordinary batteries simply cannot match. The two‑pack configuration means you always have a spare ready to swap, keeping your gear in action when it matters most.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eWhy EVE 21700‑40P? The Perfect High‑Drain Flat‑Top\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eThe EVE 40P is engineered specifically for applications that demand extreme current without compromising safety or cycle life. Using advanced INR (Nickel‑Manganese‑Cobalt) chemistry, it achieves an ultra‑low internal resistance of \u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e≤14mΩ\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e, minimizing voltage sag even under sustained heavy loads. At a full 35A draw, the voltage drop is a mere 0.49V, ensuring your drone motors maintain peak RPM, your power tool doesn’t stall under torque, and your RC car accelerates with ferocious speed. The cell’s flat‑top design is the universal standard for high‑current devices: it mates perfectly with pogo‑pin contacts in drone battery trays, recessed flat pads in power tool packs, and nickel strips for spot‑welded custom builds. There is no raised button to interfere with tight‑fitting compartments or to create uneven pressure during pack assembly.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eUnprotected by Design — Pure, Unfiltered Current\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eLike all high‑performance cylindrical cells, the EVE 40P is supplied as an unprotected bare cell. We intentionally omit the external protection PCB to keep the overall length at the standard \u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e70.0mm\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e — critical for fitting into compact drone frames, densely packed tool battery shells, and RC battery trays. Removing the PCB also eliminates the extra electrical resistance that can limit current during high‑drain pulses, ensuring your devices get every single amp they demand. Naturally, this design requires responsible use: always charge these cells with a quality charger that terminates at exactly 4.2V, and only install them in devices that have built‑in low‑voltage cutoff — a feature already present in virtually all modern drones, brushless power tools, and RC electronic speed controllers. The cell itself incorporates a built‑in PTC thermistor, resealable safety vent, and CID for passive multi‑layered protection.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eWhere 35A Continuous and 4000mAh Shine\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eThe 4000mAh capacity (approximately 14.8 watt‑hours) provides a meaningful runtime advantage over lower‑capacity high‑drain cells. In a racing drone, this translates to competitive flight times without sacrificing the instant throttle response that the 35A discharge enables. A cordless impact driver built with these cells will drive hundreds of screws on a single charge. An RC monster truck will tear through a full heat and still have power to spare. Even in high‑power portable fans or DIY power banks, the combination of high current and decent capacity means you can run demanding loads without voltage collapse. With two cells in the pack, you can build series or parallel configurations or keep a fully charged spare ready for zero‑downtime operation.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eLong‑Term Reliability and Safety\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eThe EVE 40P is rated for over \u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e500 full charge\/discharge cycles\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e while retaining at least 70% of its initial capacity. Its low self‑discharge rate means you can store spare cells at the recommended 3.6–3.7V for months, and they will still be ready when you need them. The nickel‑plated steel can resists corrosion, impacts, and the vibrations typical of drones, power tools, and RC vehicles. Built‑in passive safety layers — a \u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003ePTC thermistor\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e, a \u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eresealable safety vent\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e, and a \u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eCID (Current Interrupt Device)\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e — provide robust protection against over‑current, over‑pressure, and short circuits.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eKey Features\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e2‑Pack Value: Twice the Power\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eTwo identical EVE 40P cells. Keep one in your device and one fully charged — ideal for extended missions, back‑to‑back heats, or all‑day job site use.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e35A Continuous \/ 40A Pulse High‑Drain Output\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eGenuine high‑rate discharge handles the most demanding drones, power tools, and RC models without voltage sag. Instantaneous torque and full‑throttle acceleration are always available.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e4000mAh Genuine Capacity (14.8Wh per cell)\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eProvides a balanced runtime for high‑current applications — competitive drone flights, dozens of screws driven, or full RC heats.\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\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eStandard 70mm length and flush positive terminal ensure perfect fit in tight battery compartments, pogo‑pin contacts, and spot‑welded packs. Eliminates added PCB resistance for maximum power delivery.\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 (≤14mΩ)\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eVoltage drop at 35A is only ~0.49V. Minimal heat generation and sustained performance even under extreme loads.\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 INR (NMC) Chemistry\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eMaintains a consistent 3.7V nominal voltage with a flat discharge curve. Light output, motor RPM, and torque stay predictable throughout the discharge.\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. Holds charge for months in storage at 3.6–3.7V — always mission‑ready.\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 safety 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. Designed to handle the vibrations, crashes, and harsh conditions of drones, tools, and RC vehicles.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eTechnical Parameters\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\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\u003cspan class=\"\"\u003eBattery Model\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eEVE 21700-40P\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eBattery Type\u003c\/span\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\u003cspan class=\"\"\u003ePack Count\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e2 cells\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eNominal Capacity per Cell\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e4000mAh (14.8Wh)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eNominal Voltage\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e3.7V\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eFull Charge Voltage\u003c\/span\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\u003cspan class=\"\"\u003eDischarge Cut‑off Voltage\u003c\/span\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\u003cspan class=\"\"\u003eStandard Charge Current\u003c\/span\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\u003cspan class=\"\"\u003eMax Charge Current\u003c\/span\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\u003cspan class=\"\"\u003eMax Continuous Discharge\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong\u003e\u003cspan class=\"\"\u003e35A\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e (8.75C) — verified high drain\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eMax Pulse Discharge\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong\u003e\u003cspan class=\"\"\u003e40A\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e (\u0026lt;5 seconds)\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eInternal Resistance\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003e≤14mΩ (AC 1kHz, bare cell)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eProtection Circuit\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong\u003e\u003cspan class=\"\"\u003eNone\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e — requires external over‑discharge protection\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003ePositive Terminal\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\n\u003cstrong\u003e\u003cspan class=\"\"\u003eFlat Top (flush)\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e — no raised nipple\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eDimensions per Cell\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eApprox. 21.4mm dia. × 70.0mm length\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eWeight per Cell\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eApprox. 69g\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eCycle Life per Cell\u003c\/span\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\u003cspan class=\"\"\u003eOperating Temp. (Charge)\u003c\/span\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\u003cspan class=\"\"\u003eOperating Temp. (Discharge)\u003c\/span\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\u003cspan class=\"\"\u003eStorage Temp. \u0026amp; Humidity\u003c\/span\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\u003cspan class=\"\"\u003eChemistry\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan class=\"\"\u003eINR (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\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eApplications\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e1. Racing Drones \u0026amp; FPV Quadcopters\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eBuild a 4S or 6S high‑discharge pack for freestyle, racing, or cinematic drones. The 35A continuous output feeds brushless motors with the instant punch needed for hairpin turns and explosive climbs, while the flat‑top terminals make spot‑welding clean and reliable.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e2. Cordless Power Tools (Rebuilds \u0026amp; Upgrades)\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eReplace worn‑out cells in high‑torque drills, impact drivers, circular saws, and angle grinders. The 40P handles the 20–35A startup spikes of professional tools, and the 4000mAh capacity provides useful runtime. The flat‑top design is the standard for welding into 5S1P or 5S2P 18V\/20V packs.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e3. RC Cars, Trucks \u0026amp; Boats\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eBuild a 2S or 3S pack for 1\/10 and 1\/8 scale vehicles. The relentless current delivery means explosive acceleration, strong mid‑range torque, and enough capacity for a full race heat or extended bashing session.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e4. High‑Power Portable Fans \u0026amp; Cooling Devices\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eLarge industrial‑grade fans that draw 10–20A run effortlessly on these cells. The 4000mAh capacity provides hours of strong airflow on job sites, in workshops, or during outdoor events.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e5. DIY High‑Current Power Banks \u0026amp; Portable Inverters\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eBuild a portable power station that can fast‑charge multiple devices or run a small AC inverter. The high drain rate ensures stable output, and the 2‑pack gives you the core cells to start your project.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e6. Electric Scooters \u0026amp; Light EVs (Small Packs)\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eFor small electric scooters or hoverboards that use 21700 packs, the 40P is an excellent choice for rebuilding with high‑performance cells that deliver both current and capacity.\u003c\/span\u003e\u003c\/p\u003e\n\u003chr\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eFAQ\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ1: Is the 40P really capable of 35A continuously? How does it compare to the 50E or 40T?\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eA: Yes, the EVE 21700-40P is rated for \u003c\/span\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003e35A continuous discharge\u003c\/span\u003e\u003c\/strong\u003e\u003cspan class=\"\"\u003e, with pulse capability up to 40A. It sits between the high‑capacity 50E (5000mAh, 10A) and the ultra‑high‑drain 40T (4000mAh, 35A, but higher pulse). The 40P offers a balanced 4000mAh with strong 35A continuous — perfect for users who need both high current and decent runtime.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ2: Why is this battery unprotected and only available in flat top?\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eA: The EVE 40P is designed for high‑drain applications where a protection PCB would add unwanted length and resistance, and where a button top would interfere with tight compartments or spot welding. The flat‑top, unprotected design is the universal standard for drones, power tool packs, and RC models. It’s completely safe when used with a quality 4.2V charger and in devices that have built‑in low‑voltage cutoff. The cell’s own PTC, vent, and CID provide passive protection.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ3: Can I use this flat‑top cell in a device that originally used a button‑top battery?\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eA: It depends on the device. Many high‑performance drones, tool packs, and RC vehicles are specifically designed for flat‑top cells. If your device’s positive contact is a spring with a physical reverse‑polarity ring, a button top may be required to bridge the gap. Check your device manual: if it specifies “flat top” or “unprotected flat top,” these 40P cells are the correct choice.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ4: Can I use these 21700 cells in a device designed for 18650?\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. Never 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 hot does the 40P get at 35A continuous?\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eA: With an ultra‑low internal resistance of ≤14mΩ, heat generation is well‑managed. The cell will become warm — typically reaching 65–75°C after several minutes of sustained 35A — but stays within safe operating 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=\"\"\u003eQ6: Can I charge these batteries at 4A?\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eA: Yes, 4A (1C) is the maximum charge current. For optimal cycle life, we recommend the standard 2A (0.5C) rate. Fast 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=\"\"\u003eQ7: How should I store the spare cell?\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eA: Keep it in a plastic battery case or silicone sleeve, away from metal objects and moisture. For storage longer than one month, bring the voltage to about 3.6–3.7V (roughly 50% charge). Check every 3 months and recharge if the voltage drops below 3.0V. Never store a fully depleted cell.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"ds-markdown-paragraph\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eQ8: Can I bring these batteries on an airplane?\u003c\/span\u003e\u003c\/strong\u003e \u003cbr\u003e\u003cspan class=\"\"\u003eA: Yes. Each cell is approximately 14.8Wh, well under the 100Wh IATA limit for carry‑on luggage. Insulate the terminals and carry them in your hand luggage.\u003c\/span\u003e\u003c\/p\u003e","brand":"EVE","offers":[{"title":"Default Title","offer_id":51454109286646,"sku":"OAS181","price":16.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/2753\/6886\/files\/EVE-2pack-21700-50A-extreme-power-main_57022201-8bf5-4d55-a745-8a746c497525.webp?v=1786965291","url":"https:\/\/oneandes.com\/products\/2-pack-eve-21700-lithium-battery-40p-power-50a-discharge-lithium-battery-with-flat-top-for-drone-tool-electric-car","provider":"OneAndes","version":"1.0","type":"link"}