Here is a review of V-mount batteries from Cinegears. These are long-lasting batteries that can be used for your cinema camera (ex. URSA Mini cameras), lights and other things.
I’ve already reviewed other products from Cinegears. This is definitely a premium brand, and I’ve always been very impressed with their gear.
You can get these batteries here:
B&H Home Video
Adorama
Here are the reviews of other Cinegears products:
Here is the info on my DIY CFast to SSD storage solution.