12Pcs 3600mWh Rechargeable AA Lithium Batteries 1.5V with Charger, 8 Bay Individual Battery Charger with Fast Charging

I used these for my surveillance cameras and they last about a week depending on the tragic on my road.

My main use for these batteries is for the Blink Outdoor 4 cameras, so need the batteries to have longevity and especially to get thru the winter when changing batteries in cold weather, ice, and snow can be more challenging and problematic. Lithium batteries have consistent power output in cold weather, where alkaline and Ni-Nh decline power output declines significantly in the cold even when fully charged. I chose these batteries for the aforementioned reasons and also because of the high 3600 mWh (total energy a battery can store and deliver) so they'd last thru the winter without having to be swapped out. First, some terminology for consistency: • mWh stands for milliwatt-hours and represents the total energy a battery can store and deliver. • mAh stands for milliampere-hour and represents the battery's capacity, indicating how much electrical charge a battery can hold. These are packaged nicely with a well built charging box. However, they don't charge anywhere close to the 3600 mWh advertised on Amazon; closer to an average of 200 mWh less, which is a huge difference (see screenshots below). I used a XTAR VX4 Battery Capacity Tester and Charger, which you can get on Amazon (www.amazon.com/dp/B0D6VS3XLY). Lithium batteries discharge at a consistent 1.5V from beginning to end, even when the charge is very low near 100% depletion, so a regular battery tester doesn't work as it would show a battery as being consistently and fully charged until there was about 0% charge left (eg. a 10% charged battery would still show as 100% fully charged). This tester determines the mAh and the mWh by first fully charging the battery(s), then fully discharging them (the battery levels are determined here), then fully charging them again so you can use them (C-D-C). The mAh is not provided on Amazon's website, so I calculated it using the standard formula of mAh = mWh divided by the battery volts. So, 2400 (mAh) = 3600 (mWh on website) / 1.5 (battery's volts). Upon testing these batteries, the mAh averaged about 2300 vs. the 2400 it was supposed to be, so a lot less capacity. This isn't a huge difference, but it's still significant. The mWh averaged 3450 vs. the 3600 it was supposed to be, again lower than advertised; not huge but still significant. I included screenshots of all battery test results below (mAh and mWh are in separate screenshots). For comparison, the labels I put on the batteries show what the first mWh charge was (these numbers are not mAh in the mAh screenshot). At first when I saw the battery test results, I thought it was just a few of them, perhaps defective, but all 12 tested in the same range, so that doesn't look like a defect but more like false advertising. The Energizer Ultimate (non-rechargeable) Lithium AA Batteries have an advertised mAh of 3500, which equates to a mWh of 5250 (mWh = mAh x 1.5 volts), far superior to these rechargeable. The cost savings of using rechargeables may be good, but battery performance is more important to me, so the Energizer one-time use are the way to go. I've returned these. Below are reviews of other Li-Ion rechargeable batteries that I've tested, none that charge close to their advertised capacities: My XTAR Lithium (Li-Ion) AA Battery Review: https://www.amazon.com/gp/customer-reviews/RSUM0LDFT2FPX My SincehHoly Lithium (Li-Ion) AA Battery Review: https://www.amazon.com/gp/customer-reviews/R390K7RXXBV8VN My Delgeo Lithium (Li-Ion) AA Battery Review: https://www.amazon.com/gp/customer-reviews/R2OPXD8DHSCY37 My RayHom Lithium (Li-Ion) AA Battery Review: https://www.amazon.com/gp/customer-reviews/R2Z9KF179P01ZH My XTAR VX4 Charger & Battery Capacity Tester Review: https://www.amazon.com/gp/customer-reviews/RXTAHAOCCR0F5

I’ve had these for a long time for my grandpa, and they’ve held up really well. The battery life is excellent, and they’re super easy to grab out of the box and swap in the old batteries when it’s time for a change.

I had two batteries fail in less than 6 months.

One battery would not charge!