I ordered both 9V batteries as well as AA’s.
I haven’t used the 9V yet but the charge on the AA’s last much longer than I’ve ever had with rechargeable batteries. So I believe it’s a very wise decision to use these. They seem a bit costly but I feel they are well worth it to not have to continue purchasing shirt life batteries.

I use 9V wireless Shure ULX microphones with my PA system and have been looking for a reliable, cost-effective solution to having mics go dead over the course of a 4-set show. Putting brand new alkaline batteries in before we start playing works, but that gets expensive and contributes to e-waste. Starting a show with half-spent batteries is just asking for trouble, because they’ll probably die in mid-song somewhere, particularly given bandmates’ inability to remember to turn them off at breaks. I’ve tried about all the rechargeable NiMh and Lithium-Ion batteries out there, but some don’t hold a charge, some were DOA, and a couple actually worked, but never enough to feel good about.

I don’t normally succumb to the clickbait ads on Facebook, but when I saw the Pale Blue ad, and their clever notion of making a battery that recharges via a standard USB micro connector, I was intrigued. I ordered 4, and they weren’t cheap, but I took a chance. At the first show, as usual, bandmates left the mics on during breaks, but I decided that would be a good real-world test. The mics have a 3-segment battery level meter and every time I looked at them over the course of the show, they all showed 3 bars of battery life. When we turned them off at the end, 4 hours later, they still all showed 3 bars. The same thing happened at the next show. That’s only 2 data points (well, 8, because we used 4 mics twice), but this just may be the solution I’ve been looking for,

Life in a lav mic is never easy. The 9Vs and AAs breezed through 4+ hours of operation barely diminished. What I appreciate most is, chargers and all, the compact space needed in the audio bag and that I can charge them on the way to the gig.

We use these batteries to power some of our rental equipment. They're the only rechargeable 9V batteries (out of dozens we've tried) that hold a full charge and deliver enough power.

Pale Blue 9V is perfect for acoustic electric guitars and active pickup guitars that require a battery. Standard batteries leaked and corroded one of my acoustic electric guitars that is played less often than the others. After repairing the guitar, I decided that all of my guitars with built in tuners and active pickups deserved to have the best, so I replaced them all with Pale Blue. Now I don’t have to worry about damaging my expensive guitars with harmful (environmentally and monetarily) batteries.
Do yourself a favor and protect your investments and the environment.