Anker 621 Magnetic Portable Charger (MagGo), 5,000mAh Wireless Power Bank with USB-C Cable, Magsafe-Compatible Battery Pack for iPhone 16/15/14/13/12 Series

This was my first Magsafe battery. I had some older Qi wireless chargers and was familiar with heating issues. But these were older and lower power. Without the Magsafe feature, they were finicky and fussy and didn't properly fit around camera lens protrusions. I barely used these devices. This Anker 621 has a lot of promise. The Magsafe feature locks tight and the dimensions do not interfere with the camera protrusions, even with a case on the phone. It's compact and slim, and most importantly, does not require wires. It can be easily carried in a backpack or pocket without an accessory bag for wires and cables. When I first unpacked the battery, I fully charged with with a USB-C PD charger. It charged at 1A/5V. I used it to inductively charge my iPhone 14 Pro intermittently over the next few days. After about 10% charge, I determined the heat buildup to be intolerable. Therefore, I only used the pack intermittently. That worked fine for me over several days. When the battery was empty, it took 20Wh to fully charge. The battery was advertised for 5000mAh, which is impossible to measure without disassembling the unit. However, we can calculate 20Wh / 5V / 0.9 = 4400mAh (where 0.9 is the efficiency of the voltage converter for USB). This is below advertised capacity, but there’s a lot of assumptions in the conversion. Then I used a USB-C cable to charge my iPad Mini. It transferred 14.8Wh at about 9 Watts before exhausting. The round-trip efficiency was high, because recharging took 14.8Wh to fully recharge. I suspect I didn’t get the full 20Wh capacity with the iPad because the higher charge demand choked the battery before it could get fully empty. Using the inductive charge mode, both devices get hot relatively quickly. The switching power electronics get particularly hot. I can easily feel where the transistor is located beneath the plastic shell. The inductive transmitter loop gets warm on the battery and the receiver loop gets warm on the phone. Lithium-ion batteries degrade proportionally to temperature (the Arrhenius relationship), accelerating +25% degradation rate for every 10C, this is bad for the phone. In summary, • The battery delivers 20Wh of energy. If using inductive (Qi and Magsafe), much of the energy is converted to heat, so perhaps only 10-15Wh is actually delivered to the battery. • If using high-current devices using a charge cable, such as an iPad, the high current chokes the battery a bit early, stopping at 15Wh. • My back-of-the-envelope calculation shows 4400mAh vs. rated 5000mAh. I suspect the battery is not delivering rated capacity. Anker should be rating these batteries in Joules (watt-hours) instead of Coulombs (ampere-hours). • Inductive charging is inefficient, losing a quarter to half of energy to heat. This is not Anker’s fault but a result of real-world physics. With my iPhone 14 Pro, I saw about 10C rise per 10% of battery charge. I never let it progress beyond this point. • Lithium-ion batteries accelerate aging degradation due to the Arrhenius relationship about +25% per 10C temperature rise. Therefore, prolonged use of inductive charging will ultimately age your battery prematurely. • This battery is very worthwhile because I don’t have to carry an accessory kit with wires to use. Just slap it on the back of the phone and go. Plus, if frees the connector to use with wired headsets when using.

Really good product. Delivered without damage and the build quality of Anker is great. Not too bulky! It gets heated a bit when overused, but the magnets are very strong! It always says slow charger while using this! Not even optimal speeds is concerning, but it saves the phone from shutting down.

UPDATE 3/11/2026 - Anker absolutely honored their commitment to their product and issued me a replacement. They were quick to respond and to mitigate the issue I had with their product. Thank you ANKER!! I’m a huge Anker fan and a loyal consumer of their products, so this is the first time I’ve encountered an issue with one of their products. The charging itself works fine, the problem is that the magnetic charger gets very hot, which disrupts charging until the temperature drops. I have another brand with the same specs that doesn’t have this issue.​​​​​​​​​​​​​​​​

Technology is being changed with the way they're charged and having to buy different cables for different products has gotten so annoying. Thank goodness for magnetic chargers and adapters. I love Anker products, however this one I will say was a bit disappointing, which is why I only gave it 4 stars. I bought the pastel purple one and thought it was a good size for portability and for my small purse. It is fairly light and compact which is nice. I'm a pretty big klutz when it comes to dropping things, but I have not dropped this yet. I hope I don't, but I know their products are fairly durable. It sticks very well to my phone and it does not fall off if you shake it so you know it won't fall off. Some cons about it that I have noticed is that it does heat up a bit while it is charging and it does charge quickly. However, even though you charge the charging bank and it is full (looking at the light indicator), by the time your phone is charged up to 80%, the light indicator only has about one or two left. If you want to use it if your phone is completely dead, it will charge it, but I think that it won't fully charge it which is disappointing. I have another bulkier portable power bank of a different brand and that one doesn't even use up that much charge in one go. It's still good and it does the job, but it's a bummer that I won't be able to get a full charge on my phone if I needed it to.

So handy to use if you forget your charging cord..it seems to charge phone quickly..you do have to charge the portable charger between each phnoe charging..for me it’s not a big deal..

works exactly as described. clicks right on to the back and starts charging, no more messy chords. This fits right on my phone while traveling

The size is perfect for travel as it’s not too heavy and is pretty thin. However, charging time isn’t fabulous and I only get one charge. If my phone were to die, I don’t think this would give me a full charge. I bought to take on a cruise as there usually aren’t outlets by the bed. Typically would start charging my phone at 30% and by the time it got to 90% the battery pack would be dead. Will keep for random occasion but not the best option.

I was between buying this and a mophie charging case. If I was going to buy this one, I was going to have to get a MagSafe case as I don’t have any. And with the new iPhone 17s out and my needing an upgrade on my phone. This portable charger seemed very promising with the amount of reviews it had and a 4+ star rating. And was cheaper than the mophie case, too! With all that being said, I decided purchasing this charger would be the best option. It was definitely the cheaper route even if I did have to buy a MagSafe case. No matter, I got an Anker case for about $20. And I would still be able to use the charger on my next phone. Now, I was in search of a portable phone charger/charging case as I was going to be going to Louder Than Life. For those that don’t know what that is, it’s a 4 day rock festival usually the last or second to last weekend of September in Louisville Kentucky. And as I mentioned, my phone needs an upgrade because on any regular day, I need to charge my phone by 1pm in the day. My phones battery life SUCKS. I purchase the charger about 5 days before I leave for the fest. It arrives the next day. I took it out, made sure everything was in there and went ahead and plugged it up so it could be fully charged. Charged it over night and the next day, around 1pm when I needed to charge my phone back up, I decided to use it. I was greatly disappointed to find that I had it charging for about an hour and it had barely powered my phone 10%. And at this point, I couldn’t really buy another charger for fear of it arriving after I left for the show. So instead, decided to put up and just go ahead and try and make do at the fest. Well, I get even more disappointed when using it at the fest. In kentucky, the weather can’t make its mind up to save its life. During the fest, the highs were 87-90 out. Pretty hot. But, I had gotten the top shelf vip and was able to have shaded areas and also very AC’d areas. Mind you, I only used the charger while outside in the shaded area. With nice wind flow and fans. On the first day of the 2 my husband and I went, I began using the charger at about 5pm. I had it on for an hour to two hours. And in those 1-2 hours, it had only charged my phone MAYBE 15% and had used over half of the portable batteries charge. I even had my phone on low battery mode. And not only that, it did cause my phone to be VERY hot. On the second day of the two me and my husband was there, I used the charger again about the same time but this time for only about 30-45 minutes. Still the same issue with how much the charger was actually charging my phone, but this time it caused my phone to pause charging till my phone cooled down. I was in literally the same spot I was in the previous day. So, it ended up turning it off and just taking it off my phone. Didn’t use it again till about 7:30 and used it when I wouldn’t be using my phone at all to record anything and charged it till the next band came on around 8:30. During that hour, I got a 10% charge. Also keep in mind, during the WHOLE time I was at the fest, my phone was in low battery mode. Idk if that makes a difference, but thought I’d add that. While it isn’t able to really charge your phone without over heating it, it does have a very strong magnetic grip. The one thing I didn’t like about the magnetic thing, and this just might be where I’ve never used a MagSafe portable charger and didn’t know that they do this, is that it kinda just swung around on the magnet. While using it, the charger would get crooked and I’d have to straighten it up. Or I’d put it in my purse and it’d be sideways on my phone. Again, that might be just a thing of MagSafe portable chargers and they all do it and not be something specific to this one. I be dumb sometimes lol. But I will say, I do like how slim it is. Not bulky and taking up a lot of room. I will also say that it’s quite durable. When we got home, my husband was trying to help get stuff out of the truck and it dropped out of my purse and was still good to go! Barely even scuffed up! Overall, I’m not quite sure this charger was worth it. Especially if it’s only providing 10-15% charge in 2 hours. I didn’t like chilling with my phone on 20% for hours all day. Especially in a big crowd like that when there’s chances of my husband and I getting separated and not being able to get back to him. And I also don’t like how hot it made my phone.. it can’t be good for the phone. So, just be weary! Heed the warnings! The AI generated review overview was correct!