{"product_id":"nitecore-ums2-2-slot-smart-charger-2x-samsung-20s-flat-top-18650-battery-kit-30a-high-drain","title":"NITECORE UMS2 2-Slot Smart Charger \u0026 2x Samsung 20S Flat Top 18650 Battery Kit (30A High Drain)","description":"\u003ch2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\" data-sourcepos=\"6:1-6:19;175-193\"\u003eWhy This Bundle\u003c\/h2\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"8:1-8:460;195-654\"\u003eThe Samsung 20S is one of the hardest-hitting 18650 cells available — built for devices that demand serious continuous current. A cell this powerful deserves a charger that can monitor it closely and charge it safely. This bundle pairs 2 genuine Samsung 20S Flat Top batteries with the NITECORE UMS2, a QC-enabled dual-slot charger with a detailed LCD display, independent bay control, and multiple layers of protection — ready to use straight out of the box.\u003c\/p\u003e\n\u003cp data-sourcepos=\"8:1-8:460;195-654\"\u003e\u003cstrong\u003e\u003cspan class=\"\"\u003eThis listing is for Flat Top. Looking for Button Top? \u003ca href=\"https:\/\/oneandes.com\/product\/nitecore-ums4-4-slot-smart-charger-ui1-portable-charger-6x-samsung-25r-button-top-18650-battery-bundle\/\"\u003eClick here to buy: \u003c\/a\u003e\u003ca href=\"https:\/\/oneandes.com\/product\/nitecore-ums2-2-slot-smart-charger-2x-samsung-20s-button-top-18650-battery-kit-30a-high-drain\/\"\u003e Samsung INR18650-20S Button Top + Nitecore UMS2\u003c\/a\u003e\u003ca href=\"https:\/\/oneandes.com\/product\/nitecore-ums4-4-slot-smart-charger-ui1-portable-charger-6x-samsung-25r-button-top-18650-battery-bundle\/\"\u003e Bundle.\u003c\/a\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003ch2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\" data-sourcepos=\"12:1-12:50;661-710\"\u003eSamsung INR18650-20S (Flat Top) Specifications\u003c\/h2\u003e\n\u003cdiv class=\"overflow-x-auto w-full px-2 mb-6\" data-sourcepos=\"14:1-25:152;712-1309\"\u003e\n\u003ctable class=\"min-w-full border-collapse text-sm leading-[1.7] whitespace-normal\"\u003e\n\u003cthead class=\"text-left\"\u003e\n\u003ctr\u003e\n\u003cth class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\" scope=\"col\"\u003eItem\u003c\/th\u003e\n\u003cth class=\"text-text-100 border-b-0.5 border-[hsl(var(--border-300)\/0.6)] py-2 pr-4 align-top font-bold\" scope=\"col\"\u003eSpec\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003cbr\u003e\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eModel\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eSamsung INR18650-20S (Flat Top)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eRated Capacity\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e2000mAh (min.)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eNominal Voltage\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e3.6V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eMax Continuous Discharge\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e30A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eCharge Cutoff Voltage\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e4.20V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eDischarge Cutoff Voltage\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e2.5V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eChemistry\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eIMR (Lithium Manganese, high-drain)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eCell Size\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003e18650 (approx. Φ18.43mm × 65.0mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eTerminal Type\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eFlat Top — level positive terminal, suited for devices requiring full-surface contact\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eTypical Use\u003c\/td\u003e\n\u003ctd class=\"border-b-0.5 border-[hsl(var(--border-300)\/0.3)] py-2 pr-4 align-top\"\u003eBattery pack assemblies, power tools, high-output flashlights, electric mobility systems, and other extreme high-current applications\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003cbr\u003e\n\u003c\/table\u003e\n\u003c\/div\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"27:1-27:197;1311-1507\"\u003e\u003cem\u003eNote: This is an extremely high-drain cell — avoid mixing with batteries of a different brand, model, or charge state, and inspect the wrap for damage before every use to prevent short circuits.\u003c\/em\u003e\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003ch2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\" data-sourcepos=\"31:1-31:30;1514-1543\"\u003eThe Charger: NITECORE UMS2\u003c\/h2\u003e\n\u003cul class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\" data-sourcepos=\"33:1-40:109;1545-2595\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"33:1-33:181;1545-1725\"\u003e\n\u003cstrong\u003eUSB-C input with QC support\u003c\/strong\u003e: up to 4,000mA total output; up to 3,000mA on a single bay with a QC 2.0+ adapter, or 1,000mA per bay (2,000mA total) with a standard 5V\/2A source\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"34:1-34:111;1726-1836\"\u003e\n\u003cstrong\u003eIndependent dual-bay control\u003c\/strong\u003e: charge and monitor 2 batteries separately, without one affecting the other\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"35:1-35:202;1837-2038\"\u003e\n\u003cstrong\u003eDetailed real-time LCD display\u003c\/strong\u003e: shows battery health (Good\/Poor), internal resistance, charging current, voltage, battery type, charged capacity, charging time, cut-off voltage, and charging mode\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"36:1-36:116;2039-2154\"\u003e\n\u003cstrong\u003e3 automatic charging modes\u003c\/strong\u003e: CC, CV, and -dV\/dt, selected automatically based on battery type and charge level\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"37:1-37:96;2155-2250\"\u003e\n\u003cstrong\u003eManual adjustment\u003c\/strong\u003e: set charging current and cut-off voltage for specialized battery types\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"38:1-38:200;2251-2450\"\u003e\n\u003cstrong\u003eSafety features\u003c\/strong\u003e: automatic internal resistance detection, reverse-polarity and short-circuit protection, over-discharged battery activation\/restoration, and automatic termination on full charge\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"39:1-39:36;2451-2486\"\u003e\u003cstrong\u003eFire-retardant PC\/ABS housing\u003c\/strong\u003e\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"40:1-40:109;2487-2595\"\u003e\n\u003cstrong\u003eUniversal power input\u003c\/strong\u003e: works with wall adapters, power banks, car chargers, and solar panels via USB-C\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003ch2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\" data-sourcepos=\"44:1-44:53;2602-2654\"\u003eNITECORE UMS2 – Supported Battery Types \u0026amp; Voltage\u003c\/h2\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"46:1-46:110;2656-2765\"\u003e\u003cstrong\u003eCompatible with 3.6V\/3.7V Li-ion\/IMR\/LiFePO4 batteries\u003c\/strong\u003e, including the Samsung 20S (18650) in this bundle:\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"48:1-48:176;2767-2942\"\u003e10440, 14500, 14650, 16500, 16340 (RCR123), 16650, 17350, 17500, 17650, 17670, 17700, 18350, 18490, 18500, 18650, 18700, 20700, 21700, 22500, 22650, 25500, 26500, 26650, 26700\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"50:1-50:73;2944-3016\"\u003e\u003cstrong\u003eAlso compatible with 1.2V Ni-MH\/Ni-Cd batteries:\u003c\/strong\u003e AA, AAA, AAAA, C, D\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"52:1-52:92;3018-3109\"\u003e\u003cstrong\u003eOutput current:\u003c\/strong\u003e QC Mode — 3,000mA×1 \/ 2,000mA×2 · Standard Mode — 2,000mA×1 \/ 1,000mA×2\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003ch2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\" data-sourcepos=\"56:1-56:23;3116-3138\"\u003eCompatibility Notes\u003c\/h2\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"58:1-58:201;3140-3340\"\u003eThe UMS2 uses spring-loaded contacts that accommodate Flat Top batteries securely without any adapter. Samsung 20S Flat Top cells measure about 65.0mm, well within the UMS2's compatible battery range.\u003c\/p\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003ch2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\" data-sourcepos=\"62:1-62:19;3347-3365\"\u003eWhat's Included\u003c\/h2\u003e\n\u003cul class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\" data-sourcepos=\"64:1-67:18;3367-3483\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"64:1-64:44;3367-3410\"\u003eSamsung INR18650-20S Flat Top Battery × 2\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"65:1-65:28;3411-3438\"\u003eNITECORE UMS2 Charger × 1\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"66:1-66:27;3439-3465\"\u003eUSB-C Charging Cable × 1\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"67:1-67:18;3466-3483\"\u003eUser Manual × 1\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cstrong\u003e\u003cspan class=\"\"\u003eThis listing is for Flat Top. For Button Top\u003ca href=\"https:\/\/oneandes.com\/product\/nitecore-ums2-2-slot-smart-charger-2x-samsung-20s-button-top-18650-battery-kit-30a-high-drain\/\"\u003e click here\u003c\/a\u003e\u003c\/span\u003e\u003c\/strong\u003e\n\u003cbr\u003e\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003ch2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\" data-sourcepos=\"71:1-71:15;3490-3504\"\u003eSafety Tips\u003c\/h2\u003e\n\u003cul class=\"[li_\u0026amp;]:mb-0 [li_\u0026amp;]:mt-1 [li_\u0026amp;]:gap-1 [\u0026amp;:not(:last-child)_ul]:pb-1 [\u0026amp;:not(:last-child)_ol]:pb-1 list-disc flex flex-col gap-1 pl-8 mb-3\" data-sourcepos=\"73:1-77:187;3506-4128\"\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"73:1-73:105;3506-3610\"\u003eStore batteries in a proper case, keeping them away from loose metal objects to prevent short circuits\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"74:1-74:63;3611-3673\"\u003eNever disassemble, puncture, burn, or submerge the batteries\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"75:1-75:75;3674-3748\"\u003eCharge only with a genuine, compatible charger such as the NITECORE UMS2\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"76:1-76:193;3749-3941\"\u003eThe Samsung 20S is an extreme high-drain cell intended strictly for compatible, purpose-built devices designed for 30A continuous discharge — do not use in unauthorized or modified equipment\u003c\/li\u003e\n\u003cli class=\"font-claude-response-body whitespace-normal break-words pl-2\" data-sourcepos=\"77:1-77:187;3942-4128\"\u003eFlat Top batteries are commonly used in devices with spring or flat-contact battery holders (e.g., battery packs and power tools) — check your device's terminal requirements before use\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr class=\"border-border-200 border-t-0.5 my-3 mx-1.5\"\u003e\n\u003ch2 class=\"text-text-100 mt-3 -mb-1 text-[1.125rem] font-bold\" data-sourcepos=\"81:1-81:7;4135-4141\"\u003eFAQ\u003c\/h2\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"83:1-84:181;4143-4398\"\u003e\u003cstrong\u003eQ: Can the NITECORE UMS2 charge Samsung 20S Flat Top batteries safely?\u003c\/strong\u003e A: Yes. The UMS2 automatically detects Li-ion\/IMR chemistry and applies the correct charging voltage (4.2V) and current for 20S cells, with real-time monitoring on its LCD display.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"86:1-87:195;4400-4666\"\u003e\u003cstrong\u003eQ: What's the difference between Flat Top and Button Top batteries?\u003c\/strong\u003e A: The only difference is the shape of the positive terminal — Flat Top is level for full-surface contact, while Button Top has a raised nub. Capacity, voltage, and discharge rate are identical.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"89:1-90:142;4668-4879\"\u003e\u003cstrong\u003eQ: Will Flat Top batteries sit properly in the UMS2 charger bays?\u003c\/strong\u003e A: Yes. The UMS2's spring-loaded contacts are designed to accommodate both Flat Top and Button Top cells without any adapter or modification.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"92:1-93:200;4881-5133\"\u003e\u003cstrong\u003eQ: Can I charge both batteries at the same time?\u003c\/strong\u003e A: Yes. The UMS2 has 2 independent bays. With a QC adapter you'll get up to 2,000mA per bay simultaneously (or 3,000mA if only one bay is in use); with a standard 5V\/2A source, up to 1,000mA per bay.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"95:1-96:173;5135-5358\"\u003e\u003cstrong\u003eQ: How do I know if a 20S battery is degraded?\u003c\/strong\u003e A: The UMS2's LCD display shows battery health as \"Good\" or \"Poor\" along with internal resistance readings, making it easy to spot cells that have aged or lost performance.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"98:1-99:327;5360-5748\"\u003e\u003cstrong\u003eQ: Is 30A continuous discharge safe for everyday devices?\u003c\/strong\u003e A: No — the Samsung 20S is one of the highest-drain 18650 cells available and is intended strictly for devices specifically engineered for extreme continuous discharge, such as certain power tools, high-output flashlights, and professional battery pack assemblies. Always confirm your device's current requirements before use.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"101:1-102:110;5750-5922\"\u003e\u003cstrong\u003eQ: Can I power the UMS2 with a power bank while traveling?\u003c\/strong\u003e A: Yes. The UMS2 has a USB-C input and works with wall adapters, power banks, car chargers, and solar panels.\u003c\/p\u003e\n\u003cp class=\"font-claude-response-body break-words whitespace-normal\" data-sourcepos=\"104:1-105:114;5924-6063\"\u003e\u003cstrong\u003eQ: What's in the box?\u003c\/strong\u003e A: 2 Samsung INR18650-20S Flat Top batteries, 1 NITECORE UMS2 charger, a USB-C charging cable, and a user manual.\u003c\/p\u003e","brand":"Nitecore","offers":[{"title":"Default Title","offer_id":51454223024374,"sku":"OAS1671","price":48.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0819\/2753\/6886\/files\/nitecore-ums2-samsung-20s-flat-top-2pack-kit-main_0cdf1022-5576-4efd-814b-dd324c6fe496.webp?v=1786968575","url":"https:\/\/oneandes.com\/products\/nitecore-ums2-2-slot-smart-charger-2x-samsung-20s-flat-top-18650-battery-kit-30a-high-drain","provider":"OneAndes","version":"1.0","type":"link"}