[Lithium-ion] To test I fully charged them and a GoPro battery, then setup my Hero4Silver to video (2.7K30P,ProTune). came back every couple hrs and replaced and switched batteries and started again. On the capacity testing it looks like the videos ran within a couple minutes of each other. My watson Hero3 batteries have held up over the last 3 years like the GPs, I hope that these will achieve the same life span. As I usually swap batteries at 2 bars I like to have 3 or 4 per GoPro.

[0.1 lb] Seems to be fine and last as long as the GoPro battery, so far.

[3.8 V] So I reached out to Gradus Group (Watson distributor for B&H) regarding the battery/charger issues I had on vacation in Venice. I wasn't able to troubleshoot the issue, as I couldn't charge the battery in the GoPro 9 using the USB-C cable. GoPro 9 told me to use only GoPro batteries and then shut down, and wouldn't charge the Watson battery, nor could I charge it with the Watson dual battery charger.

Fast forward to today, Gradus Group sent me a replacement battery and charger. I placed the new battery in the charger, and it charged normally. The original Watson battery initially didn't draw a red (dead) or green (charged) light. When I checked on the charger a while latter, both batteries displayed green lights. Placed both batteries in the GoPro, neither triggered the earlier message to use only OEM batteries and both read 100% on the back screen. I labelled the original Watson battery with a white label to I can differentiate it from the replacement Watson battery. I will see if there is any difference in function moving forward.

Overall, I think Gradus Group handled the situation as well as could be expected. They assured me that this was an isolated incident for them (no history of failure or problems in the battery line [GoPro 9] or charger). They apologized for my inconvenience and sent a new replacement battery and charger.

Thanks Liam and Steve.

[Lithium-ion] just buy a bunch of these because gopro is a battery monster

[0.1 lb] It is very helpful to be able to switch out battery packs, and I love the slimmer design from the Hero 3

[0.1 lb] A suitable and quality alternative to OEM batteries. I've used Watsons for years with no complaints.

[Lithium-ion] Holds a charge for a while and saves you a few bucks. Very happy with Watson batteries.

[0.1 lb] If you own a Hero 4 you should always have extra batteries and these are the ones.

[0.1 lb] Now I have 4 batteries but I also have the LCD consumer too

[0.1 lb] I sometimes use a GoPro to get a different point of view angle for wedding videos. These batteries work as well as the originals.