Duracell Recharge Ultra Type AA Batteries 2500 mAh, pack of 4 with Duracell Power Bank 3350 mAh

This review is for the AA battery! It looks vigorous and full of energy, to be honest. Regarding the performance, I am sharing some data in the hope to help potential buyers.1. 2500 mAh, true or not ?I tested 2 randomly chosen batteries: 2624 mAh and 2649 mAh, respectively. A bit more specific, I used a specialized charger with a test mode which full discharges then charges to report battery capacity, running at 500mA discharge rate, room temperature.Among tested batteries, Duracell is the only brand with the battery capacity always more than it says!2. Does it hold?Once fully charged, I removed the batteries from the charger, and measured the voltage over a period of about 5 weeks (37 days). As you can see, the voltage does drop a bit the first few days but stabilized in about one week's time and changed little for the rest 4 weeks. Really impressive and useful: the voltage remains @1.30v after 37 days.3. Internal resistance, what is it?This is more technical but high resistance may cause the battery to heat up and the voltage to drop under load. The typical internal resistance for new NiMH rechargeable AA/AAA batteries is between 10mΩ and 100mΩ. Faulty rechargeable batteries have a much higher internal resistance.The tested Duracell AAA has a internal resistance of 15mΩ, both of them. For your reference, I have an old half-faulty battery measured at 120 mΩ.4. Will it last?Oh, no, forgive me, not in a position to test them over years! Duracell claims you could charge these batteries 400 times - I will leave this challenge to you.I am assured anyway, as the 5-YEAR guarantee seems to be the best you can get from the market.5. Am I paid by Duracell?Nope, purely out of interest, and solely out of my own pocket. I am testing other batteries and will upload my reports in due time.6. Are Rechargeable batteries better than Alkaline?Yes, most of the time. They’re safe, reliable, and most importantly environmentally friendly. They pay for themselves after a few recharges, even counting the cost of a charger.After testing AA/AAA batteries from EBL, AmazonBasics, Panasonic and Duracell, I am pretty sure it is time for rechargeable batteries and no more single-use ones to help our environment while saving you money!