PiPower turns off a few seconds after power loss

I’m using a PiPower with a RPi 3B. The PiPower is supplied by a 5V 3A USB-C power brick.
Batteries are high quality matched pair of 3000mAH.
When powered up, the batteries charge correctly and the charge light goes out once charged. All 4 battery level LEDs are lit, power is supplied to the RPi.
If I remove the power to the PiPower the battery level LEDs remain lit for a few seconds and then go out, the RPi stops.
Checking the batteries in other equipment shows that they are fully charged and hold their charge normally under load.
Do I have a defective board?
Thanks in advance

Please recorde video of your process and sending it to us. This will help us analyze the issue and assist you in finding a solution.

Thanks for the reply.
Here is the video

(Attachment PXL_20240520_091548518.TS (1).mkv is missing)

Here’s an mp4 version

(Attachment PXL_20240520_091548518.TS (1).mp4 is missing)

Emailing video didn’t work, trying here on the forum - which of course is not allowed because I’m a new user.
Please correct so that I can upload.

You can send to service@sunfounder.com or upload the recorded video to your own OneDrive account. Please share the video file link with us and grant us access permissions.

Here’s a share link


1.Please confirm that the battery is making good contact with the pipower’s battery compartment. After connecting the battery, please use a multimeter to measure the total voltage of the battery. (Please see video link for more info:video.mp4 - Google Drive)
2.After connecting the battery, please open the slide switch on the pipower.


Problem solved!
While trying to make a video I noticed that the battery voltage dropped from 8.3V to 7V momentarily when load was applied or charging removed.
Swapped out each battery in turn and found the culprit. Although it is almost brand-new and supposedly made by Toshiba, it must have a defect that makes it cut out under load.
PiPower now working normally again.

Many thanks for your time and patience

If there is anything else we can assist you with, please do not hesitate to let us know.