Product Overview
UM-18650X2 Series-Wired 2-Cell 18650 Battery Holder, 7.4V Nominal, Wire Leads, Mounting Holes
Condition
Unused. Part of the PartsMine house line, stocked new and sold by the piece. Black molded plastic body with legible markings: 3.7V, UM-18650X2, SIZE 18650 OR EQUIV, CGS diamond logo, and polarity symbols embossed. Two coil springs and gold-tone button contacts intact. Red and black wire leads attached with stripped ends ready for connection.
Same or next business day shipping from our Idaho warehouse. Reliable parts since 1999. Honest pricing, no nonsense.
Covered by our no-hassle satisfaction guarantee.
Product Overview
PartsMine UM-18650X2-Flat is a two-cell 18650 battery holder wired in series, producing a nominal 7.4V output from two standard 18650 lithium-ion cells. Pre-attached red (positive) and black (negative) wire leads with stripped ends connect directly to a switch, regulator, or PCB. Two integrated mounting holes allow secure chassis or enclosure installation. Housing is black molded plastic with nickel-plated steel coil spring contacts and gold-tone button terminals. Compatible with flat-top and button-top 18650 cells; buyers using protected cells (67-69mm) should verify fit before installing.
Key Features
- Series wiring configuration - nominal 7.4V output from two 3.7V 18650 cells
- Pre-attached red and black wire leads with stripped ends - ready for direct connection
- Black molded plastic housing - durable and lightweight
- Nickel-plated steel coil spring contacts and gold-tone button terminals
- Two integrated center mounting holes for chassis or enclosure mounting
- Molded polarity markings and cell size designation inside the holder
- No built-in BMS - buyer supplies their own protection circuit when using unprotected cells
- Compatible with standard 18650 lithium-ion cells (flat-top or button-top)
Applications
- Powering an Arduino, ESP32, or Raspberry Pi project - drop in two 18650 cells, connect the leads to a buck/boost regulator, and have a portable 7.4V supply ready for a custom enclosure
- R&D bench work - insert two cells, clip the leads to a breadboard terminal block, and swap depleted cells toollessly during testing cycles without disturbing the circuit
- RC vehicle, robotics, or motorized builds where a series 7.4V pack matches common ESC and motor driver input ranges
- Portable LED lighting rigs, camera rigs, or field instruments that run on 7.4V lithium packs
- Prop builds, cosplay electronics, and wearable projects where a lightweight, snap-in cell holder beats a fixed battery pack
Frequently Asked Questions
Is this holder wired in series or parallel, and what voltage does it output?
Series. The contact layout routes the positive terminal of one cell to the negative of the next, producing a nominal 7.4V output from two standard 3.7V 18650 cells. It is not a 3.7V parallel holder.
Will protected 18650 cells fit?
Standard unprotected 18650 cells (approximately 65mm) fit without issue. Protected 18650 cells include an integrated protection circuit board that extends total length to 67-69mm. Fit may be extremely tight or impossible depending on the cell brand. Verify your cell's physical length before purchasing if you intend to use protected cells.
Does this holder include a battery protection circuit or BMS?
No. There is no built-in Battery Management System or protection circuit. When using unprotected cells, the buyer is responsible for implementing low-voltage cutoff and overcurrent protection in their circuit.
What gauge and length are the wire leads?
Wire gauge and lead length are not confirmed for this listing. The leads are pre-stripped and ready for connection. If exact wire specs are critical to your design, contact us before ordering.
Can this power an Arduino or ESP32 directly?
Yes, with a voltage regulator between the holder and your board. The series output is nominal 7.4V, which exceeds the direct input limits of most microcontroller boards. A buck converter or 5V regulator inline brings it into range for Arduino, ESP32, and similar platforms.
Two cells in, leads out, project running - that is the whole idea. Whatever you are building, this holder takes the wiring headache off the list so you can focus on the parts that actually require your attention.
