DIY Battery Charger Case PD 100W Fast Charging for 4PCS 21700 Polymer 20000mA Battery Power Bank Box for Macbook Need Welding

Welding and installation video URL(1): https://video.aliexpress-media.com/seller/play/5000196630297.mp4
Welding and installation video URL(2):https://video.aliexpress-media.com/seller/play/5000196634143.mp4

It only the power bank case,batteries need to be welding and not included.
The battery needs to be connected in series circuit . Connect the positive pole of the battery to the "B+"end on the back of the motherboard, and the negative pole of the battery to the "B -" end on the back of the motherboard.
After welding, it is necessary to connect the power supply to charge the power bank and activate the power bank.Then it can be used normally.
Features:
A DIY power back case, can charge 4pcs 21700 batteries ( Batteries need to be welded and not included)
Support full protocol two-way PD fast charging 100W.
100W output supports PD QC- AFC SCP- multi-protocol fast charging for Laptop/phone/iPad universal
You can take it on the plane without declaration, safe and reliable
Transparent body, imported high-quality LED screen can check the remaining power in real-time
Specifications:
Item:for 4pcs 21700 Battery Charger Box
Capacity:20000mAh
Material: ABS-PVC
Color: Black
Size: approx 153x55x34MM
Input: DC 5V/3A ,9V/3A ,12V/1.5A ,10V/2.25A
Output:
Type-C 1:5V/3A,9V/3A,15V/3A,20V/5A
Type-C 2:5V/3A,9V/3A,15V/3A,20V/3A
USB:5V/3A,9V/2A,12V/1.5A,10V/2.25A
Quantity: 1Set DIY Kits (Not includes the battery and charging cable)
Note:
1.Transition: 1cm=10mm=0.39inch
2.Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid.
3.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!
Package Includes:
1Set x Power DIY Kits
Q&A
1.Q:Does this product include accessories required for welding?
A:The package only includes some accessories such as the motherboard and casing as shown in the main picture,
and the wires and other accessories required for welding are not included.
2.Q:What if there is no response when clicking the button after the battery is soldered to the motherboard?
A:In some cases, the motherboard needs to be activated after welding is completed. Charge it with a charger for 3-5 seconds to activate.
3.Q:The power display of the power bank quickly dropped to 1% and can still be used. What is the reason for this?
A:This situation is because the motherboard and battery have not yet fully matched. You can fully charge the power bank and then exhaust the battery inside it. Cycle this process 3-5 times, and the power display of the power bank will return to normal.