[Samsung Galaxy Note 8 Accessories] Notasaurus:
This is the one I bought: Galaxy Note 8 Battery Case, Himino 5500mAh Extended Battery Charger... https://www.amazon.com/dp/B07595GR35/ref=cm_sw_r_sms_awdo_nPy1zb075DR74

They all seem to be the same. Including the Zerolemon one which isn't available. Of course that's on the outside, perhaps the Zerolemon uses better cells. And I may switch to the Zerolemon one in the long run. Below is the review I left on Amazon.

The case is mediocre at best. This is just my first day with the case and my initial impression isn't great. The case back is soft touch plastic and it doesn't offer any grip. The sides of the case offer slightly more grip. The phone is held in the case securely and if you follow the instructions of pushing the phone out by the camera opening it can be removed easily enough. There is minimal front protection, the top and bottom lip only protrude about .5mm to .75mm above the glass. I can only slide 3 sheets of xerox paper between the phone screen and my desk when I lay it face down. 4 sheets will move the phone. If you drop your phone in this case, the sides should be ok but if it lands on the face I would expect the glass to break. The added weight won't do it any favors either.

On that note, I don't consider the weight a plus or minus. It's a heavy case, it's a big battery. You can carry around a battery pack of the same weight maybe a little less or you can have a convenient case that attaches directly to your phone and add the weight of the battery to your phone. Overall I feel the added weight is a fair trade off for the extra battery life.

To test the charging ability of the case,

I've discharged my phone to 10% and then turned the power off to see maximum charge I can get from the case into the phone. When I'm checking phone % charged, I'm just clicking the power button once which when powered off and charging provides a temporary screen with the phones current battery percentage. Through the charge cycle my phone remained in the "powered off" state, even though at some level it's technically not off since it still shows the charge percentage.

34% on the phone and the indicator on the back of the case turned green. The bottom of the phone case has become pretty warm over the +25% charge so far. Not necessarily hot but definitely uncomfortably warmer than I would want if this was in my pocket. Which with insulation would probably get even warmer.

43% and the indicator just turned blue. Blue means 25-50% remaining and the last "25%" (green) only provided about 10% actual charge for the phone (for the record I charges the case for 6hrs before first use and made sure it stopped charging and had time to cool down before using it).

92% and the indicator is still blue, the case temp has decreased, likely due to the phone accepting a charge more slowly as the battery fills up.

100% with the indicator still blue. Case is cool to the touch.

Definitely seems to be some discrepancy between the LED indicator percentage and the actual percentage remaining in the case battery.

This leaves me with a few thoughts. Perhaps there is a problem with some of the cells leading to quick percent changes through the 100% down to 50% (White and Green) portion of the charge cycle. Maybe the quick charge function of the phone is maxing out the charge circuit and it is running far below peak efficiency leading to more heat and less power being transferred. I'll charge the case over night and if possible turn off quick charge on the phone to see if it I can get better performance out of the White and Green portion of the charge cycle. But so far the case provided one full charge in about 2hrs 14mins with the phone off and supposedly has >25% left in the tank.

Overall I don't expect to use this case as my primary case. While the extra battery life is nice, the lack of sufficient screen protection and limited grip make this a need to use only case. My Note 8 doesn't have a problem lasting through my day and I usually have enough battery life left to get me through the night and well into the next day. I bought this case for the times when I travel where I usually use my phone constantly and battery life can become a challenge and for that I think it will be sufficient. I've rated it 3 stars to be fair as I think 2 is too low, but if I could I would rate it 2.5.