BAK 21700 Batteries

BAK 21700 cells are a builder's workhorse — dependable, established lithium-ion cells that cover everything from runtime-focused packs to tabless high-drain output.

BAK is one of the longer-running names in cylindrical lithium-ion, with cells found across e-bikes, power tools, and energy storage worldwide. For a pack builder, that maturity translates to predictability: cells that behave consistently and deliver solid value rather than chasing headline numbers.

Stepping up from 18650, the BAK 21700 range gives you options at both ends — higher-capacity cells when runtime is the goal, and tabless high-drain cells when you need strong, sustained current. Either way you get the extra capacity and energy headroom the 21700 format brings over 18650.

Why builders choose them

• Established, proven cells from a long-standing manufacturer
• 21700 capacity and energy advantage over 18650
• Both high-capacity and tabless high-drain options available
• Dependable, value-driven cells for serious builds

Built for

• E-bike and light EV battery packs
• Power-tool packs and high-drain rebuilds
• Energy storage and portable power
• Custom 21700 pack assembly