I have a Watson LPE6 battery that I've used in a 5D3 and a 5D4 with no problem. The Watson held a charge almost as well as a Canon battery. At least it did for 4 years, now seems to lose charge quicker. Maybe it's just getting old. One of the Canons is at least 4 years old and will still take 2500 shots on one charge. That is now showing only 1 bar for rechargablility. Watson is good, Canon is better.