Samsung 25R 2500mAh 20A Flat Top Battery 2-Pack with Nitecore UM2 Smart Charger – High-Drain Power Bundle for EDC Lights, Drones, and Custom Packs

What’s in This Bundle:

• 2x Samsung 25R 2500mAh 20A Flat Top Batteries – Factory-fresh, high-drain 18650 cells.

• 1x Nitecore UM2 Intelligent Dual-Slot Charger – Smart charging with LCD display and QC 2.0 fast input.

• 1x USB-C Charging Cable – Ready to plug into wall adapters, power banks, or laptops.
  (Note: This kit does not include an AC wall adapter.)

Product Description:

If you're building a custom battery pack or running high-performance EDC gear, you need a cell that delivers under load. The Samsung 25R has been the trusted standard for years, and for good reason. It puts out a genuine 20A continuous discharge—enough to handle heavy-duty flashlights, drones, or DIY power packs without voltage sag or overheating.

This bundle gives you two brand-new 25R flat-top cells and the Nitecore UM2 charger. The UM2 takes the guesswork out of charging. It detects battery chemistry automatically—Li-ion, IMR, LiFePO4, or Ni-MH—and applies the exact charging profile the cell needs. The LCD panel shows you voltage, current, and capacity in real time, so you're not left wondering.

It supports QC 2.0 input, pushing up to 1500mA per slot. That means a 3500mAh cell can reach 80% charge in just over two hours. It also includes an IMR-optimized charge program for high-drain cells, and a repair mode that can revive over-discharged batteries you'd normally throw away.

Reliable power doesn't need to be complicated. This kit gets it right.

Key Benefits:

• 20A continuous output – Stable, sustained current for high-drain builds.

• Up to 35A pulse burst – Handles sharp power spikes when you need them.

• Fast QC 2.0 charging – 1500mA per slot cuts down charge times.

• Smart battery detection – The UM2 reads your battery and picks the right charging mode.

• LCD real-time display – View voltage, current, and capacity instantly.

• Built-in repair mode – Revives over-discharged or dead cells.

• Comprehensive safety – Reverse polarity, short-circuit, and overheat protection.

Technical Specifications:

Battery - Samsung 25R (Flat Top):

• Brand: Samsung SDI

• Model: INR18650-25R

• Capacity: 2500mAh

• Voltage: 3.6V / 3.7V

• Continuous Discharge: 20A

• Pulse Discharge: Up to 35A (short bursts only)

• Standard Discharge: 10A (for longer cycle life)

• Internal Resistance: ≤18mΩ

• Chemistry: Li-ion NMC

• Cut-Off Voltage: 2.5V

• Operating Temp (Discharge): -20°C to 75°C

• Cycle Life: 250+ cycles at 20A

• Weight: 45g

Charger - Nitecore UM2:

• Input: DC 5V/2A, 9V/2A (QC 2.0)

• Max Output: 1500mA per slot

• Total Output: 3000mA

• Display: LCD (voltage, current, capacity)

• Protection: Reverse polarity, short-circuit, overheat, over-charge

Complete Battery Compatibility List:

• Dimensions: 152mm × 73mm × 40mm

• Weight: 148.3g

Applications:

• EDC flashlights and headlamps

• Drone and UAV battery systems

• DIY 12V and 24V battery pack builds

• Portable power stations and solar generators

• High-drain remote-controlled models

Frequently Asked Questions (FAQ):

Q1: What's the real-world difference between 20A continuous and 35A pulse?
A: The 20A rating is the safe, long-term current you can pull without damaging the cell. The 35A rating is what the battery can deliver in short, milliseconds-long bursts—like starting a drone motor. You shouldn't run it at 35A continuously; that would overheat the cell and shorten its life. Treat it as a 20A battery and you'll be fine.

Q2: Can I use the UM2 charger with LiFePO4 batteries?
A: Yes. The UM2 automatically detects LiFePO4 cells and switches to the correct 3.2V charge profile. No manual setup is required.

Q3: What should I do if the charger shows "EE EE" on the screen?
A: That's the charger's way of saying it found a battery that's been over-discharged or is possibly damaged. The UM2 has a built-in repair mode—just press and hold the "V" button to try to revive a deeply drained cell.

Q4: Can I charge different battery sizes at the same time?
A: Absolutely. The UM2 has two independent slots, so you can charge an 18650 in one slot and a 21700 in the other without any issues. Check the compatibility list above to ensure both sizes are supported.

Q5: Can I power the UM2 from a power bank or solar panel?
A: Yes. The USB-C input makes it compatible with wall adapters, power banks, car chargers, and even portable solar panels—ideal for field use or road trips.