What is a Power Bank Module?

A power bank module is the printed circuit board (PCB) that handles charging, voltage conversion, and protection in a power bank. Think of it as the brain and safety systems combined.

What You’ll Need for a DIY Power Bank

• The module: The PCB you buy online.
• Batteries: Most commonly 18650 lithium-ion cells; purchased new or salvaged (only if tested healthy).
• Battery holder or soldering tools: Modules may have solder pads or pre-attached wires — prepare accordingly.
• Enclosure: Plastic, metal, or 3D-printed case sized to fit cells and the module.

Key Specs to Check Before Buying

• Input/output specs: Look for supported charging input (for example, 5V/2A) and output current (for example, 5V/2.1A). Advanced modules may include Quick Charge (QC) or USB-C Power Delivery (PD).
• Cell count compatibility: Modules are built for a specific number of cells (1, 2, 4, 6 × 18650, etc.). Match this to your desired capacity.
• Features: LED indicators vs. digital displays, built-in flashlight, passthrough charging, etc.
• Protection: Confirm the listing explicitly mentions over-charge, over-discharge, short-circuit and over-current protection.

Where to Buy & Price Expectations

Common places to find modules:

• Local marketplaces: Sites like Jumia and Konga often carry basic modules and parts. Expect affordable, quick-shipping options.
• International marketplaces: AliExpress, Banggood and similar stores offer a wider selection, including PD/QC-capable modules — but allow time for shipping and possible customs.

Typical price range (local markets): ₦800 to ₦3,000 for common modules. Advanced modules with PD/QC will cost more and may be easier to find internationally.

Safety Tips & Final Notes

• Only use batteries in good condition. Test salvaged cells for capacity and internal resistance before use.
• Observe correct polarity when connecting cells to the module.
• Never short battery terminals — use insulated tools and holders.
• Work in a well-ventilated area and keep a basic fire extinguisher nearby when first testing new assemblies.
• If you are new to electronics, consider practicing on inexpensive modules and holders before building a high-capacity pack.