Kratax Lithium Batteries AA Rechargeable 4 Count 1.5V 3500mWh Li-ion Rechargeable Batteries with 2H Battery Charger, 1600 Cycles Long-Lasting, Constant Voltage Output for XBox Controller, Electric Toy

Charged super fast and the battery is still full, only been a couple days but better than regular batteries in my opinion, my last set of batteries were just regular disposables and they'd only last the day, I use them in my steelseries xl pro controller and they have not let me down yet, so I'd say yes, 10/10 would recommend

They are a little pricey! But they work fine!

I have about 20 of these now and none have failed. I use them mostly in audio devices (wireless microphones, portable recorders, and mixers, etc.) They clearly have much more power than NiMH rechargeables, and because they deliver 1.5V instead of the 1.2V you get from other rechargeables, some devices work considerably better (shavers, portable LED lights, etc.) The only real downside is that because these cells have their own internal voltage regulator for a constant 1.5V, you never know how much charge remains. If your device shows the battery level, it will always show full until the charge is completely gone. Also, note that any rechargeable AA or AAA Li-Ion cell requires a charger that dows 1.5V. You should not try to charge them on a charger meant for NiMH.

I needed more and more for the Blink cameras. I bought these last year so I went back to add more. The old batteries that I used for the last year and they lasted the year without needed replacement (what I wanted as some of these are in the woods and snow and mess of the woods from the yard. That's for a good product and good delivery.

Update 8/13/2022: the camera is not responding, so I swap in the other two and got it up again. It’s been consistently lasting 30 days. Pretty good. Definitely save some money.Update 7/13/2022: today the camera is not responding. I swap in the other two batteries aTo get it back online again. So it lasts exactly one month in a high traffic area (35-40 events a day, record the maximum one minute each time). So there you go, these rechargeable batteries last 4 weeks versus Energizer 7 weeks. These rechargeable make don’t last as long, but will save month in the long run.Original review 6/12/2022:I bought these for my Blink XT2 cameras. The Energizer ultimate lithium are too expensive and my camera happens to be in high traffic area. I will eventually pull a usb cable in the future, but for now I’m giving these rechargeable lithium batteries a try.After I receive these (4 pack), I installed two, and also put the other two in charger, so I can run a comparison. The first two runs fine, but the red low battery symbol stayed for entire day and doesn’t seem to go away. I then swap out and put the other two, freshly charged, into the camera. It took maybe 10 minutes for the low battery symbol to go away, so there you go. Make sure you charge them when you receive.No idea how long it’s going to last. For comparison, the energizer lasts about 7 weeks. I will report back on how long these rechargeable can do.

Charger works really well…However 3500 be a bit of a stretch…They run outta gas real quick…I’ll try them in a different appliance….Just to be fair

Good batteries

So I've purchased around 50 of these over the last year for my business - we use them in wireless mics, clickers, and wireless in-ear monitors. They work well and last a long time however there is something I noticed that is a potential problem - these DO NOT charge like a regular li-ion battery. I purchased some larger smart chargers to charge them and I found that they do not fully charge. I believe this is due to the charging regulator inside the batteries themselves. A typical li-ion charges at 4.2 volts - but these, if you read the fine print, need to be charged at 5 volts. So I can use the larger smart chargers to charge them initially up to roughly 97%, but to get them to 100% charge, I need to put them into the "dumb" chargers that come with the batteries as those run off USB (5 volts). Kind of a pain but still a money saver over alkalines, especially when you consider we'd go thru several hundred alkalines a year prior to moving to these...UPDATE: Just had the 1st casualty. Battery rolled off the table and dropped on the concrete floor (about 3') and the end broke open. It's completely dead. Hopefully it's just a fluke...