Li-ion Battery Case Adapter — Rechargeable Battery Holder with USB Output

Turn Your Rechargeable Cells Into a Portable Power Bank

The Li-ion Battery Case Adapter is the smart way to repurpose your rechargeable lithium-ion cells into a portable USB power source. Load it with compatible Li-ion cells, and it instantly becomes a compact power bank with USB output — complete with a built-in protection circuit to keep your devices and cells safe. When the cells wear out, swap them. No waste. No replacement cost. Just reliable portable power on your terms.

Key Benefits

• Li-ion Cell Compatible — works with standard rechargeable lithium-ion cells; use cells you already own
• USB Output — charge phones, earbuds, and other USB devices directly from the adapter
• Built-In Protection Circuit — over-discharge, overcharge, and short circuit protection for both cells and connected devices
• Replaceable Cells — swap out worn cells instead of replacing the entire unit; more sustainable and cost-effective
• Compact Housing — lightweight, portable design that doesn't add unnecessary bulk
• LED Indicator — visual status indicator for power and charging state

Whether you're a DIY electronics enthusiast, a prepper building a custom power kit, or someone who wants a power bank with truly replaceable cells — this adapter delivers. It's the most flexible and sustainable approach to portable USB power. Load it with high-capacity cells for maximum runtime, or use cells you already have on hand. When they wear out, swap them and keep going.

Frequently Asked Questions

What cells are compatible?
Standard rechargeable lithium-ion cells in the compatible format. Check the product specifications for exact cell size compatibility (e.g., 18650, 21700).

Are cells included?
No — cells are not included. You'll need to source compatible rechargeable Li-ion cells separately.

Does it protect against over-discharge?
Yes — the built-in protection circuit prevents over-discharge, which can permanently damage lithium-ion cells.

Can I charge the cells while they're in the adapter?
This depends on the specific model. Check the product details for charging capability — some adapters support in-case charging via USB input.

How do I replace the cells?
Open the case, remove the old cells, and insert new compatible Li-ion cells with correct polarity. No soldering required.

SPECIFICATIONS

Cell Type: Rechargeable Li-ion (not included)
Output: USB
Protection: Over-discharge, overcharge, short circuit
Indicator: LED status
Design: Compact, replaceable-cell housing
Weight: 0.22 lbs / 0.102 kg (without cells)