Very good battery obviously used extensively and keep their word. That said, if the use that we want is a moderate use, it is better to fall back on the batteries "low end", even changing more often if you do not mind because the price difference will be justified no. Personally, I've used on a wireless system adapted to my guitar, so I have no right to what they it rip me during a concert and I do not change every two hours either. With these batteries, I was totally serene, they held just over 8 hours (after about 6 hours by security I have removed and then used in repetition), autonomy was higher by approximately 2 hours compared to conventional batteries. I am very satisfied, but that satisfaction has a price. So you really know what use you intend for them.