Built by a Builder, for Builders
21700Supply started in a small town in Iowa — not in a warehouse, not by a reseller. By someone who was already building battery packs and got tired of not being able to source quality, authentic cells without a runaround.
A Family Business Built on Builds.
We are a father and son team out of small town Iowa. Between us, we have spent years building custom battery packs — Milwaukee M18 rebuilds, DeWalt 20V replacements, electric scooter packs from scratch. That hands-on experience is the foundation of everything we do here. Right now, 21700Supply is focused on selling the cells themselves: tested, graded, and exactly as rated. Down the road, the goal is to launch our own line of pre-built Milwaukee and DeWalt replacement packs built the right way. Until then, we sell the best cells we can find so you can build them yourself.
Why It Matters
We Only Sell Real Cells
The battery market is full of rewrapped cells, inflated specs, and mystery sourcing. We know because we built packs with those cells — and learned the hard way what bad stock does to a build. Every cell we sell is sourced directly, capacity-tested, and graded before it ships. No mystery wraps. No inflated specs. Just the cell, exactly as rated.
Where We Come From
Built on Real Experience.
Power Tool Pack Background
Years of rebuilding Milwaukee M18 and DeWalt 20V packs gave us a ground-level understanding of what cells actually perform — and which ones don't.
Electric Scooter Builds
Custom pack builds for electric scooters taught us cell selection, S/P configuration, and how much cell quality matters when a build has to perform reliably.
Cell Testing & Grading
Every cell we sell is capacity-tested before it ships. We post batch data so you know exactly what you're getting — no guessing, no inflated specs.
What's Next
Our goal is to launch our own line of pre-built Milwaukee M18 and DeWalt 20V replacement packs. Built right, tested, and backed by the same standards we apply to every cell we sell today.
Gallery
What We've Done
Ready to Build?
We sell the cells. You do the build. Shop our tested 18650 and 21700 stock.