PowerbankCase · Replaceable 21700
Swap the cell.Keep the module.
An assembled power bank module that takes one replaceable 21700 cell. Choose green or gray, buy the parts separately, or pick a kit with the cells and charger you need. No soldering required.
One module. One replaceable cell.
Each module holds one 21700 cell. The cell compartment opens so you can replace the cell when needed and keep using the same module.
Disconnect your device before changing cells. Follow the polarity marks and the supplied instructions when inserting a compatible cell.
USB-C and Lightning, built in
Rotate the built-in connector to use USB-C or Lightning with a matching device. The module also has a separate USB-C port.
Check the connector fit with your phone case before use. Charging speed depends on your device and the supported input and output ratings.
A four-level battery indicator
The module uses four indicator levels to show the remaining battery charge at a glance.
The indicator gives a charge-level estimate. It does not display a precise battery percentage or live port wattage.
Charge your spare cells separately
The separate charging case has four slots for flat-top 21700 cells. Choose it on its own or include it with the Complete or Duo kit.
A charger is not included with the bare module, Starter kit, or Travel kit. Review the package list for the option you select.
Buy the parts you need
Modules, cells, and the charging case are available separately. Add another module or replace a cell without buying a full kit.
21700 cells
Choose one cell or the four-cell pack pictured. Seller-rated 5,000mAh per cell.
Shop cellsChoose what comes in your kit
Starter, Travel, and Complete kits come with a green or gray module. The Duo kit includes one of each color. Cell counts below include the cells used inside the modules.
Starter kit
Module + cells
1 module + 1 cell
Start with one module and the cell it needs.
$49
Bought separately: $51. Save $2 with this kit.
Travel kit
Module + cells
1 module + 4 cells total
One cell for the module and three spare cells.
$69
Bought separately: $78. Save $9 with this kit.
Complete kit
Charger included
1 module + 4 cells total + charging case
Add the four-slot charger to your module and spare cells.
$99
Bought separately: $117. Save $18 with this kit.
Duo kit
Charger included
2 modules (Green + Gray) + 4 cells total + charging case
Two modules, four cells to share, and one four-slot charger.
$129
Bought separately: $156. Save $27 with this kit.
Visit the product listing for current kit and individual-part prices, package contents, and current checkout availability. Review the order total before payment.
The module and charger at a glance
- Cell format
- One 21700 cell per module
- Colors
- Green or gray
- Built-in connectors
- Rotating USB-C and Lightning
- Additional port
- USB-C
- Battery indicator
- Four levels
- Charging case
- Separate four-slot charger
- Module dimensions
- 49.4 × 26 × 90mm
- Charging case dimensions
- 96 × 64 × 65mm
Dimensions and the supplied cells' 5,000mAh rating are stated by the seller. A four-cell pack totals 20,000mAh across four separate cells; the module uses one cell at a time. Device charging capacity also depends on voltage and conversion losses.
Your module and kit questions, answered
What each kit includes, how cells fit, and what to check before ordering.
Does the modular power bank need soldering?
No soldering required. The PowerbankCase charging module arrives assembled and uses one replaceable 21700 cell. Follow the supplied cell setup instructions.
Which kit includes the cells and charging case?
Starter includes one module and one cell. Travel includes one module and four cells. Complete adds a four-slot charging case to Travel. Duo includes two modules, one green and one gray, four cells, and a charging case. Counts include any fitted cell. Standalone modules do not include batteries.
Can I use any 21700 battery?
Each module uses one replaceable 21700 cell. The separate four-slot charging case supports flat-top 21700 cells only. Contact support@powerbankcase.com with the manufacturer and model before choosing third-party cells; the format name alone does not establish compatibility.
What do the battery indicators show?
Four battery-level indicators show the module's charge level, illustrated at 25%, 50%, 75%, and 100%. Follow the supplied instructions to interpret their behavior.
Does the four-cell pack make one 20,000mAh power bank?
No. Each supplied cell has a nominal 5,000mAh capacity, and the module uses one cell at a time. Four cells are separate batteries, not a 20,000mAh battery inside one module. Nominal cell capacity is not the rated usable USB output capacity.
Which charging connections does the module have?
The rotating built-in connector offers USB-C and Lightning, and the module has a separate USB-C port. Check your device and phone-case fit. Confirm the input and output ratings for your intended connection; maximum charging power and protocol claims are not established here.
Is worldwide shipping included?
Yes. Free worldwide shipping is included. Review Shipping & Delivery and Returns & Warranty before payment. Contact support for dispatch and delivery estimates.
How do I order?
Review the configuration and current checkout availability on the product page. When checkout is available, choose your configuration, add it to your cart, and review the order total and payment methods before paying. If checkout is unavailable, no payment is collected; adding to cart or creating an account does not place a paid order.