Battery Cells

Lithium Battery Cells for Custom Packs, Repairs & High-Drain Builds

Every battery pack starts with the cell, and the cell you choose determines almost everything about how that pack performs — how much capacity it holds, how much current it can safely deliver, and how long it lasts before capacity starts to fade. At Mach 1 Lithium, this collection brings together individual battery cells across the formats DIY builders and repair techs actually use: 18650, 26650, and LiFePO4 chemistry cells from established manufacturers, sold individually or in packs so you can buy exactly what your build needs.

Understanding the Formats in This Collection

Cell size and chemistry aren't interchangeable, and picking the right one starts with knowing what each is actually built for. Our EVE 33V 18650 3200mAh 10A Battery and EVE 25P 18650 2500mAh 20A Battery Cells represent two different priorities within the same 18650 format — the 3200mAh cell favors higher capacity for longer runtime, while the 25P's 20A continuous discharge rating suits builds with heavier current draw, like high-torque tool batteries or e-bike packs. Similarly, our Samsung 30Q 18650 3000mAh 15A Battery balances the two, a common choice for builders who want dependable output without over-specializing for one use case.

If your project calls for LiFePO4 chemistry instead — valued for its stability and long cycle life over standard lithium-ion — our 26650 LiFePO4 Battery Cell 3.2V 3400mAh and K2 26650 3.2V 3800mAh LiFePO4 Battery Cells are built in the larger 26650 form factor, giving you more capacity per cell while keeping the safety margin LiFePO4 is known for. This makes them a strong fit for solar storage builds, backup power packs, or any application where you're cycling the battery frequently and want it to hold up over years rather than months.

If you're not sure which format or chemistry actually fits your project, our guide on what makes 18650 batteries good breaks down the specs that matter — capacity, continuous discharge rating, and internal resistance — so you're buying based on what your build needs rather than just the biggest mAh number on the label.

Buying Cells That Actually Match Across a Pack

One detail that trips up a lot of first-time builders: cells in a multi-cell pack need to be matched in capacity and internal resistance, or the pack will discharge unevenly and one weak cell can drag down the performance of the whole group. Buying cells from the same batch and manufacturer — rather than mixing loose cells pulled from different sources — is one of the simplest ways to avoid this problem before it costs you a rebuild.

From Loose Cells to a Finished Pack

Cells are only the starting point. Once you've picked the right ones for your voltage and capacity target, you'll need to join them into a pack, insulate the connections, and typically add protection circuitry before it's ready for regular use. Our Spot Welders collection has the tools for joining nickel strip to cell terminals without overheating them, and our guide on what DIYers and pros need to know about battery spot welders covers the technique if this is your first weld job. From there, our Heat Shrink & Connectors collection protects the exposed joints, and a Battery Management System keeps the finished pack balanced and safe during charge and discharge cycles.

For the complete picture of what a build requires start to finish, our DIY Battery Building hub lays out every component in order, so you're not left guessing what to add to your cart alongside the cells.

Why Builders Source Cells From Mach 1 Lithium

Sourcing cells from unreliable sellers is one of the most common ways DIY builds go wrong — mismatched capacity, inflated discharge ratings, or cells that are simply older stock than advertised. Every cell in this collection is sold with its actual specs, not inflated marketing numbers, because a pack built on honest data about its cells is a pack you can actually trust once it's sealed up and in use. Whether you're repairing an existing battery or starting a build from a bare cell count, this is where that build starts.