Description
Upgrade your 8-Channel Lithium Battery Tester to support 21700 cells with this dedicated 4-slot adapter module.
This expansion base allows your native 18650 tester to properly fit and test 21700 lithium-ion cells. The module replaces the standard 18650 holders and provides the correct spacing and mechanical support required for accurate and stable testing of 21700 batteries.
Important
Each module supports 4 cells only.
To fully convert an 8-channel tester for 21700 use, you need 2 modules.
This is a mechanical adapter base. It does not include the tester.
Why You Need It
If you are testing modern high-performance 21700 cells such as Samsung 50S, Molicel P45B, EVE 50PL, JP40, JP50, or similar models, proper cell contact and alignment is critical for accurate internal resistance and capacity readings.
Trying to fit 21700 cells in 18650 slots leads to poor contact, unstable readings, and possible mechanical stress. This adapter solves that cleanly.
Key Features
• Designed specifically for the 8-Channel 18650 Lithium Battery Tester
• Supports 21700 lithium-ion cells
• 4 independent slots per module
• Strong mechanical support and proper terminal alignment
• Plug-and-play installation
• Clean and professional fit
Compatibility
Compatible with the 8-Channel 21700/18650 Lithium Battery Auto Charge/Discharge Tester sold on DIY500AMP.COM.
Not compatible with other testers unless dimensions match exactly.
What’s Included
• 1x 4-Slot 21700 Adapter Module
To convert the full 8-bay tester, order quantity: 2
Important Notes
• Tester not included
• Power supply not included
• For 8-cell 21700 testing, two modules are required
• External discharge function remains available through the tester




