K2 26650 LiFePO4 Battery Cells
If you're building a custom battery pack in Dallas or anywhere in Texas, choosing the right cells matters. The K2 26650 3.2V 3800mAh cells offer solid capacity and reliability for DIY solar banks, RV power, deer feeders, and power tool rebuilds. This guide walks you through what makes 26650 cells different, how to size your project, and what else you need to complete a safe build.
What Are K2 26650 LiFePO4 Cells?
26650 cells are larger cylindrical batteries than the common 18650 format. The "26650" refers to dimensions: 26mm diameter and 65mm length. K2 26650 cells use LiFePO4 (Lithium Iron Phosphate) chemistry, which means they run at 3.2V nominal and deliver long cycle life with excellent thermal stability.
The K2 version offers 3800mAh capacity per cell at $8 each. Compared to smaller 18650 battery formats, 26650 cells pack more energy into each unit, which can simplify your build if you need higher capacity without adding too many cells in parallel.
These cylindrical cells work well for projects where you want to build your own configuration rather than buying a pre-assembled pack. Texas DIY builders use them for everything from off-grid solar storage to portable hunting power.
K2 vs Real Cell 26650 – Which Should You Choose?
Mach 1 Lithium carries two 26650 options: K2 at 3800mAh for $8, and Real Cell 26650 at 3400mAh for $4.50. Here's how to pick.
K2 26650 (3800mAh, $8): Higher capacity means longer runtime per cell. Best for projects where you want maximum energy density and don't mind paying a bit more per cell. Good for solar banks, RV house batteries, and applications where space is tight but you need serious amp-hours.
Real Cell 26650 (3400mAh, $4.50): Lower cost per cell. Best for budget builds, testing/prototyping, or applications where you can add more cells in parallel without space concerns. Works fine for deer feeders, small camping power packs, or tool battery rebuilds where total cost matters more than squeezing every mAh into the pack.
If you're building a 12V 100Ah solar bank, the capacity difference adds up. K2 cells would need fewer parallel groups to hit your target, which can simplify your BMS and wiring.
Common Uses for 26650 Cells in Dallas
Solar battery banks: Off-grid cabins, RV house batteries, and backup power systems. 26650 cells in series/parallel configurations can replace lead-acid batteries at a fraction of the weight. Check out deep cycle battery options if you want pre-built alternatives.
Deer feeder batteries: Long-lasting power for remote feeders. LiFePO4 cells handle temperature swings better than lead-acid and don't need maintenance. Browse hunting and camping power solutions for ready-made options.
Power tool battery rebuilds: Some builders use 26650 cells to upgrade old NiCad or NiMH tool packs. You'll need to match voltage and fit, but the capacity boost can be worth it.
Portable power packs: Custom camping/tailgating batteries. Build exactly the capacity and voltage you need instead of settling for off-the-shelf limits.
If you'd rather skip the DIY route, Mach 1 offers 12V LiFePO4 batteries that are ready to use.
$1.45 USD
$5.15 USD
$8.00 USD
$4.99 USD
$4.51 USD
$4.99 USD
What Else You Need for a DIY Build?
Buying cells is step one. Here's what else you need to complete a safe, functional battery pack.
Battery Management System (BMS): Protects your cells from overcharge, over-discharge, and short circuits. Pick a BMS that matches your series count (4S for 12V, 8S for 24V) and can handle your max current draw. Check battery management systems for options that fit 26650 builds.
Spot welder or pre-tabbed cells: You'll need to connect cells with nickel strips. A Sunco spot welder makes clean, strong connections without overheating cells. Read the battery spot welder guide for tips on technique and safety.
Nickel strips: Pure nickel (not nickel-plated steel) conducts better and handles high currents. Get the right width for your pack's amp draw.
Cell holders or heat-shrink tubing: Keeps cells organized and insulated. Heat-shrink tubing is cheap and effective for small packs.
Charger: Use a LiFePO4-compatible charger set to 3.65V per cell max. Don't use a standard lithium-ion charger (4.2V) or you'll damage the cells.
Browse the full DIY battery building collection for everything you need in one place.
Shipping & Availability in Dallas
Mach 1 Lithium ships nationwide, including to Dallas and all of Texas. LiFePO4 cells are safer to ship than standard lithium-ion because they're more thermally stable, but they still follow USPS/UPS hazmat guidelines.
Assumption: Standard ground shipping to Texas typically takes 3–5 business days from Mach 1's warehouse, though exact times depend on your location and carrier. Check the product page for current shipping estimates.
Bulk orders: If you're building a large pack (20+ cells), consider ordering everything at once. Shipping costs per cell drop when you consolidate, and you'll have all your components ready to go instead of waiting on multiple shipments.
If you need help sizing your order or confirming compatibility, reach out to Mach 1 support before you buy. It's faster to ask upfront than to reorder later.