18650 Battery Tester can be used with 21700 battery holders. Cycle charging and discharging: only support charging-discharging-charging 1 cycle in automatic mode, do not support multiple cycles. Charging current: each channel independently maximum about 1A, and charging current is not adjustable.
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18650 Battery Tester + Portable Storage Protective Case Box For aaa/aa/18650/9V Battery Organizer Container Cover For Battery
Aliexpress UK
18650 Battery Capacity Internal Resistance Tester X1. Note: Lithium iron phosphate battery charging is not supported. Information link.
eBay
18650 Lithium Battery Capacity Tester Module Digital Two Channel 18650 Battery Power Detector Tester Module Type-C Interface
Aliexpress UK
Does not support lithium iron phosphate battery charging. Supports individual charging and up to 9 charging/discharging cycles in automatic mode. Maximum charging and discharging current is about 1A.
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DIY 12V 3S Power Wall Battery Holder 18650 Battery Pack Flushing Protection BMS 18650 Battery Box Can Be Stacked
Aliexpress UK
• Accurate Battery Testing : The 18650 Lithium Battery Capacity Tester Module MAh MWh Digital Battery Power Detector Module 18650 Battery Tester provides accurate testing of battery capacity, ensuring that you know exactly how much power is left.
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4 Channel 18650 Lithium Battery Capacity Tester Module Digital 18650 Battery Power Detector Tester Module Type-C Interface
Aliexpress UK
18650 battery capacity internal resistance tester X1. 4 Channel Battery Tester Data link: （English）. 2 Channel Battery Tester Data link: （English. Note: lithium iron phosphate battery charging is not supported.
eBay
Selianenergy 100PCS MNC 18650 Battery 3.7V Rechargeable Lithium Ion Battery for Flashlight Battery cell DIY 12V 24V 48V
Aliexpress UK
Load power: 10W 8Q. automatic save without operation 5 seconds after the value setting is complete. Long press: data zero.
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18650 rechargeable battery 3.7v 3200mAh 10A Batterie de décharge INR18650-MH1 18650 rechargeable battery lithium ion battery
Aliexpress UK
Does not support lithium iron phosphate battery charging. Supports individual charging and up to 9 charging/discharging cycles in automatic mode. Maximum charging and discharging current is about 1A.
eBay
8 Channel 18650 Battery Capacity Internal Resistance Tester DC 5V 10A Automatic Charging and Discharging Module 2.4 Inch Screen
Aliexpress UK
Red light=lithium ternary battery. 1: Press and hold the key for 2 seconds to enter the setting state: the mode light (battery 1 type) flashes, and the string number light is always on; Briefly press the key to select the battery type.
eBay
18650 Battery Rechargeable Battery 3.7V 18650 9800mAh Capacity Li-ion Rechargeable Battery For Flashlight Torch Battery+Charger
Aliexpress UK