Have 5 of them and their CS is great. I've always ran lithiums but decided to try the rechargeable battery packs. Bought two knockoffs on Amz last summer & very impressed with them. Ordered another bundle of 4 more last week for $80. That'll give me 6 battery packs, so will always have an extra ready to go.
For whatever reason, the battery packs don't fall off as quick as regular lithium batteries. My experience has been that lithiums usually go from 30% to 0 overnight. I purposely let one of the packs go as long as possible. Changed one out last week that progressively went down to 1% and still was taking pics.