If it looks too good to be true then it probably is!
I guess the adage if it looks too good to be true then it probably is!
Buying 10x 18650 batteries with ostensibly three times the typical capacity for batteries of this type for not much more than the price of a single battery of a reputable brand fits this adage.
In tests on two of these batteries on low power computing devices (TTGO ESP32 module), including fully recharging them before use (based on the charger detection of fully charged), these batteries will only power the device for a three or four hours doing the demo "hello world" display, whereas a 3000mAh battery from a reputable brand will power my fully fledged project which includes an addon RTC clock module an SD card reader and multiple sensor devices whilst connected to the WiFi for 24 hours.
If they weren't so cheap I would probably bother to send them back to the vendor.
Verified purchase: YesCondition: New