AnkerNano Power Bank with Built-in USB-C Connector, 5,000mAh Portable Charger 22.5W, for iPhone 16/15 Series, Samsung, iPad Pro/Air, and MoreECOLOGO

I see a bunch of one-star reviews, mostly from people who seem confused about battery capacity, energy, power, voltage, current, etc.People complain that this little pocket-size battery won’t fully charge their iPad. That’s like buying a little one-gallon gasoline can for emergencies, and then complaining that it when you poured it into your truck’s empty gasoline tank it didn’t fill the tank all the way to the top.The cell inside the Anker Nano Power Bank is advertised as having a capacity of 5000 mAh. That means the cell can (for example) supply 5 A for one hour, or 2.5 A for two hours, or 1 A for five hours. Battery engineers like talking about mAh because it is useful for their circuit designs, but for the rest of us it’s not very useful, because knowing the energy in 5000 mAh depends on knowing what voltage we are talking about. For end users, it is more useful to compare batteries based on the energy they store rather than the amount of current they use to deliver that energy. So that means talking about watt-hours (Wh) instead of mAh.For this battery the cell voltage is about 3.6 V, so 5000 mAh gives you 18 Wh.But phones aren’t designed to take power at 3.6 V. Phones require 5 V (or higher). Voltage conversion circuitry is not perfectly efficient. The text on the battery itself claims, “2600 mAh @ 5V x 2.4 A,” which means it can deliver 2.6 x 5 = 13 Wh of energy. This means that the voltage conversion circuitry inside the Anker Nano is about 72% efficient, so the 18 Wh at 3.6 V becomes 13 Wh at 5V (28% of the energy is wasted as heat). In practice, measuring a couple of Anker Nano Power Banks using a USB energy meter, I found they actually deliver 12 Wh (2.4 A @ 5V for one hour). 12 Wh is close to the 13 Wh that Anker claims, but not quite.My iPhone 15 Pro Max has a battery capacity of 17.32 Wh. Charging a battery is also not perfectly efficient — charging makes your phone get warm, and that heat is more wasted energy. If we assume that battery charging is also 72% efficient, then the 12 Wh from the Anker Nano becomes 8.64 Wh in the phone battery, or about half of the my iPhone 15 Pro Max battery capacity. In my experience the Anker Nano does indeed charge my phone from empty to around 50%.Because the Anker Nano supports USB C voltage negotiation, phones that support higher voltages can request up to 10V, allowing the Anker Nano supply up to 22 W for faster charging than a normal USB 5 V supply.The Anker Nano Power Bank is great for unplanned situations where you unexpectedly find your phone battery is drained. The Anker Nano is a small battery that easily fits in a pocket or a bag, and you don’t need to remember to carry a cable with it, because the built-in USB C plug connects directly to the device being charged. If you prefer to use a cable, it also has a USB C socket for that.Last year at the end of a day of skiing I found myself trapped for two hours in a broken-down gondola with four other people. All of their phone batteries were drained, and they were concerned about how they could tell their friends where they were. I pulled the little Anker Nano out of my pocket and passed it around. Within a few minutes everyone had charged their phone 10-15%, enough to call their friends and let them know what was happening.

This is small and compact. Easily fits into my day pack without taking up much space or adding weight.I bought this as a second battery for when I'm traveling and exploring, and need to rely on having my phone charged up to access maps, directions, reservations, etc.I've only been able to test this a few times with my Google Pixel phone. Starting from 10% phone charge remaining, this battery was able to charge my phone all the way up while the screen was on and playing YouTube videos over WiFi before the battery was fully drained. To be completely fair, the battery was fully spent by the time it got the phone completely charged.With the screen off and the phone doing nothing, I bet this would charge the phone fully at least 1.5 times?

so far it’s good, i use it for work so it’s nice to not have to rely on a cord that gets in the way.

UPDATE:I've changed my review from 2 stars to 4 stars. Anker seems to be a legitimate honest copy -- they contacted me shortly after my review and offered to refund my money back. They seem to care about their customers, which is a rare thing nowadays with most other companies. So A+ on the customer service! It appears the item I received had a faulty battery. Since Anker stands by their product, and communicates back with the buyer and is honest, I wouldn't hesitate to try buying from this company again. It seems I was one of the rare 3 or 4 people out of a thousand to get a faulty battery. I guess it wasn't my day.OLD:I tested the “Anker Nano Power Bank with built in USB-C connector” and the results were not impressive at all. However, it's possible this maybe because I got a bad charger.Here's what my test showed:Using the power bank charged fully to 100%, I plugged the Anker power bank into my phone. My phone has a 5000mah capacity battery – the same amount of power that Anker claims the Nano can provide. The power bank charged exactly 1 hour and 8 minutes before it died at 0%. My phone was at 27% battery life before charging. After charging my phone with the Anker Nano, it was only able to get my phones battery up to 91% from 27%. So, that’s 27% to 91%. That means this Anker Nano power bank only provided 64% of charge...Doing the math, that means that this is either a bad product; there’s been some false claims, or I received a half functioning dud with a bad battery If the Anker Nano I received isn’t a dud, then that means this power bank is only capable of 3200mah and not the 5000mah power Anker claims or advertises.However, I understand most power banks will be about 10 to 15% off from the mah power that manufactures claim. But since the Anker Nano could only provide my 5000mah phone with 64% juice, that equals out to 36% deficiency in it’s mah power claims. That’s pretty high seeming this is suppose to be a well known and trusted top company.So overall, I’m not impressed at all and feel a little cheated after testing it out. There are several other brand options I could've choose from in around the same price range, so I’m not feeling certain I made the right choice and feel pretty dissapointed.PROS:-It’s compact. It looks nice.CONS:-1 hour and 8 minutes charge time before power bank dies.-Provides only 64% juice to a 5000mah phone battery before it dies.-Doing the math, 64% = 3200mah of power, not 5000mah of power as described by Anker’s description. (...however, it is possible mine may be a dud??)Conclusion: I plan to test some more Anker and other branded products in the future, and I will update once my comparison is complete. I am still searching for a lightweight charging option that works with at least 80% efficiency, as most good power banks do.

The USB connection broke off after about 5 months. I talked to the support team at anchor and they sent me a new power charger. I received it within 2 days. This company is above and beyond. I will definitely buy again. Thank you Anker.

Anker is my go-to brand for these power banks and cables. This one is awesome for two reasons - the size is perfect to stick in a pocket and carry around, and the built-in USB-C connector means no more worrying about cables.It sort of extends the bottom of the phone when it's plugged in which makes it very easy to use the phone while charging it.Of course, since it's small it has limited capacity, but it's enough to pretty much give me one full charge and that's all I really need routinely.