These are great rechargeable batteries and they work as described.

These are great rechargeable batteries and they work as described.  Read Less

First, I love these batteries. They bring new life to devices that perform poorly with 1.2 volt NiMH batteries like audio and v...  Read More

First, I love these batteries. They bring new life to devices that perform poorly with 1.2 volt NiMH batteries like audio and video recorders. However, there are things you should know before committing to using any 1.5 volt rechargeable lithium battery:1. The AA's I've received in the last two shipments are 2,000mAh rather than the advertised 1,850mAh. That's mentioned in the Amazon ad, but it's in the middle of the product page and hard to find.2. When using any recording product (audio recorders, video cameras, wireless microphones, etc.), the device's battery meter will not accurately represent the power remaining. That's because the voltage of this type of battery puts out a constant 1.5 volts until they're depleted, at which time the voltage will rocket to 0 volts. Usually, a recorder will detect the consistent voltage decline of normal (alkaline or NiMH) batteries and leave enough in reserve to finish writing the digital file to memory before automatically shutting down. These batteries won't do that, which means the current recording file will likely become corrupted when the power expires. Therefore, it's best to start and stop the recorder from time to time or determine how long the batteries will provide power to your device and set a timer to remind you when to press stop, power down, and change out the batteries.3. Unlike others I've used, these batteries lack the lip at the top of the battery. I usually grab that lip with my fingernail whenever I change the batteries in a device. Without that lip, these batteries may be difficult to extract (depending on your device.)4. Some devices can charge NiMH batteries when connected to AC. But rechargeable lithium batteries can't be charged in any device and can only be charged by connecting them via their built-in USB connector. I'm not sure if attempting to charge (either on purpose or by accident) these batteries would result in damage or fire, so make sure to identify if you have such devices and take great care to remove rechargeable lithium batteries before connecting a power supply.5. Photography strobes will not work with rechargeable lithium batteries. You'll only get a flash or two before the 'battery depleted' indicator lights up, so NiMH batteries are best for strobes.Based on all that, I will buy even more of these batteries for my wireless microphones and trail cameras. They're fantastic in devices that can benefit from 1.5 volts nominal.  Read Less

I've got AA battery-powered temperature sensors in both my refrigerator and freezer. Most types of batteries don't work well on...  Read More

I've got AA battery-powered temperature sensors in both my refrigerator and freezer. Most types of batteries don't work well once they get below 0°F but I've read that lithium can still operate down to -40°F. That made these AA'a the perfect choice for my situation: They're Lithium and they're rechargeable so economical in the long run.I've had them in use continuously for the last month and they've been perfect. When I used to use NiMh rechargeables or alkalines, the temperature readouts, especially from the freezer, would often become intermittent especially below zero. That has stopped happening completely. Once I charged the Blackubes up using the 4-headed USB cable that comes with them, they have performed perfectly, 24/7, ever since.  Read Less