Why does the power bank discharge quickly when charging other devices?

Usually, an external battery could supply 60%-70% power to other devices. Approximately 30-40% of the battery capacity is lost in circuit heat and voltage conversions, which means that a fully charged PowerCore 10000 can only offer 6000-7000mAh battery capacity to your devices. Therefore, please get to know the battery capacity of your device first to find out the correct charging times the power bank should provide.

 

If you now get fewer full charges for your devices than you used to get via the power bank, or you find the power bank is losing power much more quickly than before, please try the following tips to see whether it is helpful:

  • Make sure you do not leave a USB C to lightning cable in the portable battery (with USB C PD port) when the power bank is not used. The USB C to lightning cable will drain power automatically even though there is no device connected.
  • Do not use the devices when they are charged via the power bank to see whether it helps.
  • Charge the PowerCore fully again, try another cable and try the power bank on another device to see how it works.
 

If the troubleshooting does not solve the problem, please contact us for further assistance.

Unresolved icon
89 undefined
Which Anker power banks are allowed on a flight?
61553 views13 likes/2025-04-07 18:26:51
What is Trickle Charging Mode?
53700 views28 likes/2025-04-18 15:18:53
Power Banks’ Charging Issues
51874 views10 likes/2025-04-07 17:53:24
Anker Warranty Policy
11251 views1 likes/2025-12-29 17:30:41
How to verify the authenticity of Anker products?
13814 views1 likes/2025-12-29 17:31:54
How to Recharge Anker 525 Power Bank (PowerCore 20K)
13354 views2 likes/2025-04-07 17:16:08
Warranty Claims for Quality-Related Issues
10306 views2 likes/2025-12-29 17:31:50
Introduction to the Anker 737 Power Bank 24K (A1289)
32694 views3 likes/2025-04-07 17:53:47
Play videoQuick Start Guide Anker Nano Charger (45W, Smart Display, 180° Foldable)
Quick Start Guide Anker Nano Charger (45W, Smart Display, 180° Foldable)
Play videoAnker Prime Power Bank (26K, 300W)Quick Start Guide
Anker Prime Power Bank (26K, 300W)Quick Start Guide
Play videoAnker Prime Power Bank (20K, 220W)Quick Start Guide
Anker Prime Power Bank (20K, 220W)Quick Start Guide
Contact Us
anker link

USA:
For Anker Charging: 1-800-988-7973

Mon - Fri: 6 AM - 5 PM (PT)

anker link

Mon - Sun: 8 AM - 4 PM (PT)

Buy on the Anker Store
anker link

Hassle-Free Warranty

anker link

30-Day Money-Back Guarantee

anker link

Fast, Free Shipping

anker link

Lifetime Customer Support

Amazon American Express Apple Pay Diners Club Discover Google Pay Mastercard PayPal Shop Pay Venmo Visa