Ampace 21700 Batteries

Ampace 21700 batteries are high-drain, tabless lithium-ion cells built for demanding pack builds — pairing the added capacity of the 21700 format with the low internal resistance and strong sustained output that tabless construction delivers.

Ampace is a newer name in cylindrical lithium-ion, focused specifically on high-power tabless cells. Its 21700 line — represented by cells such as the JP40 (4000mAh, 70A class) — is aimed at builders who need genuine current delivery and a balance of capacity, without stepping up to the cost of the longest-established high-drain brands.

What sets these cells apart is the tabless design. A conventional cell connects its electrode through a single welded tab, which creates a resistance bottleneck and a hot spot under heavy load. A tabless cell connects along the full edge of the electrode instead, dramatically lowering internal resistance. In practice that means less voltage sag under current, cooler operation, and more stable sustained output — exactly what high-drain packs ask for.

Key features

• Tabless construction for low internal resistance and reduced heat under load
• High continuous-current capability for demanding, high-drain applications
• 21700 format — more capacity and energy headroom than 18650
• Strong performance-to-value position among modern high-drain cells

Common applications

• Power-tool battery packs and rebuilds
• E-bikes, e-scooters, and light electric mobility
• High-drain RC and hobby builds
• Custom and professional 21700 pack assembly