Just received my Sofirm SP31 as per the $10 deal on Amazon. Very nice floody light. However I’m playing with it on an LG H2. The Sofirm-branded battery is still charging. I’m just curious if anyone has any knowledge about the supplied Sofirm 2800 mah button top that comes with the light. With or without the battery, it was a great deal. I’d just like to know if anyone can confirm the battery as a keeper. Thanks in advance. 
My Opus 3100 gave me 2680 on the one I got when I ran a discharge test on it. However the Opus only charges to 4.15v so the battery wasn’t fully charged. At least capacity wise it seems to be fairly labeled.
Yeah, it’s as rated. I run a flat top in my SP31 though: That protected one sticks a quarter/half inch out the back and I don’t want to compress the springs that much. Works great in my Zanflare F1 which accepts much longer cells gracefully. I considered it a free bonus with the light. And the light is comparable to a BLF A6. It’s good for $10.
The cell is mediocre it has extremely high internal resistance so its only good for low drain devices. Also the harder you push the cell the more capacity you will lose.