8.4V 2A Charger for 2S 7.4V Li-ion Battery Packs – 5.5×2.1mm

8.4V 2A Charger for 2S 7.4V Lithium-Ion Battery Packs

Charge compatible 2S lithium-ion and lithium-polymer battery packs with an 8.4V charging voltage and DC 5.5 × 2.1 mm connector.

This charger is designed for 2-series lithium battery packs with a nominal voltage of 7.4V and a fully charged voltage of 8.4V. It can be used with compatible battery packs assembled from 18650 or 21700 lithium-ion cells.

Common compatible applications may include DIY 2S battery packs, portable electronics, LED bicycle-light battery packs, hobby projects, and other equipment that uses a compatible 7.4V lithium battery pack.

Important: Compatibility requires the correct battery chemistry, pack voltage, charging current, connector size, and polarity. Please compare the specifications of your original charger and battery before use.

Product Specifications

• Charger output voltage: 8.4V DC
• Maximum charging current: 2A
• Compatible battery configuration: 2S
• Compatible nominal battery voltage: 7.4V
• Compatible fully charged voltage: 8.4V
• Connector size: DC 5.5 × 2.1 mm barrel plug
• Designed for lithium-ion and compatible lithium-polymer battery packs
• Suitable for compatible 18650 and 21700 cell-based battery packs
• US wall plug

Common Applications

• 2S 7.4V lithium-ion battery packs
• DIY 18650 battery packs
• DIY 21700 battery packs
• Compatible LED bicycle-light battery packs
• Portable electronics and lighting projects
• Hobby and custom battery-powered equipment

Compatibility Requirements

Before ordering, confirm that your battery or original charger requires all of the following:

• 2S lithium-ion or lithium-polymer battery chemistry
• 7.4V nominal battery voltage
• 8.4V charging voltage
• Up to 2A charging current
• DC 5.5 × 2.1 mm barrel connector
• Matching connector polarity

The battery pack should contain a properly installed and functioning battery management system, or BMS, designed for 2S lithium-ion charging.

Not Compatible With

• Single-cell 3.7V or 4.2V lithium batteries
• 3S, 4S, or higher-voltage lithium battery packs
• 12V lead-acid batteries
• NiMH or NiCd battery packs
• LiFePO4 battery packs requiring a different charging voltage
• Devices with a different connector size or polarity
• Battery packs that cannot safely accept a 2A charging current

What Is Included

• One 8.4V 2A lithium battery charger with US wall plug

What Is Not Included

• Lithium battery pack
• 18650 or 21700 battery cells
• Connector adapters
• Other accessories

Safety Information

Use this charger only with a compatible, properly assembled 2S lithium battery pack. Do not use it with damaged, swollen, overheated, leaking, improperly wired, or unprotected battery packs.

Charge lithium batteries on a nonflammable surface and do not leave them unattended while charging. Disconnect the charger if the battery or charger becomes unusually hot, emits an odor, changes shape, or behaves abnormally.

Additional Parts and Resources

For battery-building components, BMS boards, connectors, holders, conductive materials, and related supplies, visit RenewSpark.

For helpful battery tools, calculators, technical information, and additional resources, download the RenewSpark Tools app.