Coast AA USB-C Rechargeable Batteries, ZITHION-X, Lithium Ion 1.5v 2400 mAh, Long Lasting, Charges Under 2.5 Hours, Charging Cable Included, 4-Battery Pack

I have a bunch of both the AA and AAA. Didn't realize how many I needed so I set this up on Subscribe and Save and replace a few each month. These last just as long in everything I have tested them in as the Energizer E2 ultimate lithium. So far I have tested these in my headlamps, flashlights, remote controls, wireless keyboard and mouse and battery powered shades (using Panasonic Eneloop D cell adapters). The battery powered shades go up and down at exactly the same rate and respond just as quickly to the remote as the previous Duracell D cells. Expensive, but they charge quickly and I keep an extra set on hand for the headlamps I use every day so I always have some charged and ready to go. Waiting for them to make a 9V. I'm not using them for safety items like smoke alarms or my Spot device. I still use the Energizer E2 ultimate lithium for those.

These work like a charm and battery seems to have good life

So far I have been very pleased with these. They power my Bose noise cancelling headset in my helicopter helmet and they have really impressed me with how long they last. First impression is they last longer than good quality alkaline versions and they charge quite quickly with the helpful charge status lights.

I've tried rechargeable lithium AA/AAA batteries from EBL, Hixon, Deleepow, Soshine, and XTAR. While the XTARs were the best experience out of those, all of them fell short in key ways. They all self-discharged rapidly. Their capacity claims are purportedly for the lithium cell inside, not the power you can expect to be delivered to the device after conversion. So rather than claim the companies are lying about the internal cell I'll just say that their designs are terribly inefficient at stepping down the 3.7v of the internal lithium cell, with the exception of XTAR which was just mildly inefficient. The biggest issue being a significantly cheaper Ni-MH cell will outperform every one of these batteries in runtime (the XTAR being the best performer had less runtime than a standard Eneloop in an LED flashlight), the only situation where these lithium cells make sense is where having a constant 1.5v is critical to the devices operation, but this also makes it impossible to know how much power is remaining in the batteries as you use them. The XTARs (newest model as of this review) have a feature that drops the voltage to 1.2v as the internal cell battery voltage runs low, but this is so close to empty that it might as well be empty in any high-drain application where these batteries would be an appropriate choice over Ni-MH.These Coast batteries are a huge leap in the right direction. Using my SkyRC NC2200 I am getting between 2600-2800mah when discharging at 500mah, more power than is stated by the manufacturer. They also seemed to artificially lower their voltage on a curve as the battery discharges. My Garmin eTrex SE has a feature to tune the battery gauge to specific battery chemistries, and to my surprise the only accurate setting was the one for Alkaline.The built-in charging is important for my use as well. I plan on using these for multi-day camping / backpacking trips. I only want to carry one battery bank and one type of cable for the trip and charge all my devices that way to minimize items and weight. With these batteries my handheld GPS and headlamp can last multiple days use, I can tell when they need to be charged, and if they need to be charged I can do so without an extra charger or cable in my bag.There are a couple of cons. The biggest is the price. $10 per cell is kind of insane, but just try and find another rechargeable lithium AA that compares right now. Another con is weight. These weigh considerably more than disposable lithium cells which are also more energy dense. For backpacking, it would be seriously worth the effort to understand how long your AA devices last and if you should just go disposable and bring a couple extra disposables. Another con is that these cells are now only on-par with some of the high capacity Ni-MH batteries which are considerably cheaper.

Delivered at 1.5 volts. Charged to 1.6 and they stayed at 1.58 when unused for a few weeks. In my Logitech remote they are reading 1.38 volts after a month.I guess I should compare them to NMHi batteries in the remote. Do far, I'm happy.

They do not hold the charge. Total waste of money......I am not recommending this product..

I use these for EDC and professional photography. The ability to travel without a rechargeable charger or spare alkalines is ideal. Coast has really done an excellent job, especially when these are on sale.

Build quality is questionable. Feels like a factory designed product, cable quality is poor, USB port is very tight and sticky. Not sure, but they don't seem to last as long as my other batteries.