Certainly didn't expect the $7 gold battery to have lNFC out 4200mah.
Turns out to be only about 70% capacity to stock, and charges at same rate.
Quite distinctly, the battery is made out of 2 smaller batteries laid laterally. You can see the dividing line and bent the battery slightly.
No NFC, no flickering voltage inconsistencies, usable up to 0%.
Good enough as a cheap short term backup for $7.
Next up, is a $5 0.65A battery dock charger. Wonder how long it takes to charge a flat to full.
My guess 8 hours.