@neverdie according to a few datasheets 2v at 200lux. The solar cells delivered were HENGYANG SC-3514.
On my windowsill, 2.5v typical in-direct sunlight, 2.7v is the highest I've recorded in direct sunlight.
So far, most of my Aliexpress buys have been fine for my needs. Haven't really gotten close to making a "production ready" module, so for prototyping it's been fine.
One exception: I thought I had a genius idea to repurpose these $1 solar powered keychain flashlights. They had an amorphous solar panel, rechargeable battery, button, leds and a housing...for $1. I bought 20 of them. First one I opened up, I realized it's a lie!
The solar panel is just glued to the circuit. The battery is just a normal non-rechargeable CR2016.