You would think that reviewing a battery pack would be a simple exercise. In fact, on a normal tech podcast, it would go something like this: “I got this nifty Qi2 battery pack – it’s thin and light and it has a capacity of 5000mAh. It’s only $20!” But you just know that’s not how this review is going to go. First, let’s take a quick stroll down memory lane.
The OG MagSafe Battery Pack
When Apple came out with the first MagSafe battery pack for iPhone it seemed like a dream come true. But when you got into the details, the product was kind of odd. The battery only had a 1460mAh capacity, and to charge it you had to buy separately a 20W power adapter and a lightning cable. 20W today is common but back then it was something most people didn’t just have lying around.
It would charge your phone at a feeble 7.5W. But get this — it could charge at 15W, but only if it was plugged into that 20W power supply while charging your phone. That kind of defeats the purpose of a portable battery pack if you have to plug it in.
It weighed 4 oz and was .43 inches thick (0.43 x 2.50 x 3.75 Inches). At least it was expensive at $99.
It was a great idea and we all wanted one at first, but the limitations were far to great for most people to push the “buy” button. Apple eventually dropped the product.
Qi2 For the Win
With the introduction of the Qi2 standard, we can now have battery packs for our phones that deliver 15W of wireless power, and sport a USB-C charging port. Remember Qi2 exists because Apple gave its technology for MagSafe to the Wireless Power Consortium.
At one of the CES press events, we interviewed a representative of the Makeblock company who sells a line of laser cutters for home use under the brand xTool. The interview was especially fun because friend of the show, friend of ours, and podcaster Richard Gunther of The Digital Media Zone walked up and joined us. It turns out he has one of the xTool laser cutters and so I asked him to join in the interview. Sadly you don’t get to hear the interview just yet, but I promise there’s a reason all of this is relevant to talking about Qi2 battery packs.
The folks that make the xTool laser cutter gave Richard and me an XCOOL Qi2 battery pack. Get it? XCOOL sounds like xTool. And that’s what I’m actually going to review today.
XCOOL Specs
The XCOOL Qi2 battery pack has a capacity of 5000mAh (already quite a bit more than the anemic 1460mAh of the Apple MagSafe battery pack. Apple’s offering was a chubby .43 inches thick, while the XCOOL is only .31 inches thick. That doesn’t seem like much of a difference, but you notice 27% thinner. It’s only a smidge lighter though at 4.5 oz. In the hand it’s sleek and feels great in the hand. The Apple charger did have lovely rounded edges though, whereas the XCOOL has sharp edges like the current iPhones.
Since it’s Qi2, it delivers power to your phone at the full 15W fast charging without needing to be plugged into power. If you do plug it in, it can deliver 20W of charge. It has four white indicator lights to show you the charge level.
In the box, they include two optional accessories for your XCOOL battery pack. If you have a non-MagSafe case on your phone, or you’re using an Android phone, they include a magnetic ring to stick to your phone or case. They also include a USB-C charging cable for the battery, but no power adapter which is becoming the norm.
The other accessory is quite clever. It’s a very small strip of metal that you stick .5″ away from the bottom of the battery. A portion of the metal strip is hinged to fold out to form a kickstand. It sounds janky as I describe it, but it works surprisingly well in both landscape and portrait orientations of the phone. I like that it’s super thin so it adds no noticeable bulk to the battery.
The XCOOL 5000mAh battery pack lists for only $40 on Amazon, but as of the time of this writing it’s only $30. And as of the time of this writing, there’s a $10 coupon so it’s only $20. It comes in grey, green, black, white, red, silver, and purple for me and Sandy.
If 5000mAh isn’t enough for you, XCOOL also comes in a 10,000mAh format but that will bulk it up to .59 inches thick and 6.9 oz and it’s listed for $50 on Amazon, but there’s a $20 coupon bringing it down to $30.
Any normal tech podcaster/reviewer would stop here. But when I told a few people about this battery pack they told me they had a 5000mAh battery pack from Anker.
Anker
I know that Anker is a well-loved brand, so I looked up the 5000mAh Anker 621 Magnetic Portable charger. It lists for $40 on Amazon but is currently discounted to $28. That’s just a smidge more than the XCOOL. However, Anker’s 5000mAh battery is even chubbier than Apple’s old battery, coming in at .45 in vs .31 for the XCOOL. Anker’s battery is also a bit heavier at 5 oz vs. 4.5 for the XCOOL. The Anker 621 MagGo comes in the requisite purple, black, light blue, light green, and white.
If it weren’t for the thickness, I’d probably lean towards recommending Anker over XCOOL because of the brand even though it’s a smidge more expensive.
Testing
Before I could give the XCOOL the Podfeet stamp of approval I decided to actually charge my phone with the XCOOL battery. What I discovered surprised and dismayed me. The iPhone 16 Pro has a rated capacity of 3582mAh, and my battery health is still at 100%. I slapped the XCOOL on the back of the phone without a case to charge.
I expected the 5000mAh battery to easily fill the iPhone’s 3582mAh battery from its starting point of 14%, but the XCOOL was out of juice when the phone’s battery was at 84%. That means the phone only gained 70% of its capacity. 70% of 3582 is only around 2500mAh. That means I only got about half the capacity of the XCOOL battery.
The XCOOL, in spite of its name, did get a bit hot to the touch while charging the phone. I checked it with my handy dandy laser thermometer and it was a toasty 106.1°F. That’s not crazy hot, but any signs of heat mean loss. You may notice that your phone heats up when on a MagSafe charger but it doesn’t when it’s plugged in via USB-C or Lightning.
Remember that using MagSafe (or Qi2 to speak more generically) is using what’s called inductive charging. The phone and the charger both have a coil of wire in them. When electricity flows through that wire on the charger, it induces a magnetic field. When the coil in the phone senses the magnetic field induced by the charger’s coil, it causes the reverse effect — electricity flows through the coil in the phone, charging its battery. This process of inducing a magnetic field and converting it to an electrical current is inherently lossy.
What I didn’t appreciate was how lossy it might be. I didn’t think it would be a loss of 50% as I found in my test of the XCOOL battery.
It was time for more experiments. I asked Richard Gunther if he would be able to run the identical experiment for me. He ran his battery down pretty low, took the case off (so we don’t add more loss by an air gap.) He sent me the details of his phone, including the model (iPhone 15 Pro) so I could look up the capacity, and maybe equally important, he told me his battery health. His effective charge of his phone from the XCOOL 5000mAh battery pack was also right around 2500mAh (2472), or 50%. His battery also died before he got to the full charge of his iPhone.
My buddy Ron saw my XCOOL a few days earlier and bought one for himself, so I enlisted him in the experiment group. His results were better than mine and Richards. While he required about the same amount of charge on his iPhone as me and Richard, the battery still had one of its 4 lights on when his phone was 100% charged. We did some math to prorate the effective charge he could expect from his battery and it came out almost 2900mAh. That’s still only 58% of its rating.
Finally, I asked Sandy Foster to test her Anker 621 MagGo which you’ll remember is also 5000mAh. Again, with no case, she was able to get to 100% with 1 light still on the Anker. If we prorate her results like we did Ron’s, that means the effective charge capacity of the Anker was 3387mAh, or 67% of the promised 5000mAh. That’s a lot better than any of our tests with the XCOOL.
However, there’s an obvious flaw in my math and that’s assuming that 1 light of 4 being lit up is exactly 25% capacity left. What it really means is somewhere between 25% and 0%. The stats I collected really mean that the available charge is no more than 3387mAh for the Anker and no more than 2900mAh for Ron’s XCOOL.
I know I’m the only one still interested in the topic, but I ran the test on my XCOOL again, and also remembered Steve got an XCOOL too so I tested it on my phone. My results were pretty much in line with the others, showing 2687mAh for my second test, and 2328mAh for Steve’s XCOOL.
I put all of these results in an accessible Markdown table in the shownotes if you want to see all of the data I collected.
| Tester | 5000mAh Battery Model |
iPhone model |
iPhone rated battery capacity |
iPhone battery health |
Effective iPhone battery capacity |
iPhone charge start |
iPhone charge end |
Net charge gain (charger drained) |
Effective capacity Gain |
|---|---|---|---|---|---|---|---|---|---|
| Sandy | Anker 621 MagGo |
15 Pro | 3274mAh | 97% | 3176mAh | 20% | 100% | 80% | 3387mAh (Proration from 75%) |
| Allison | XCOOL | 16 Pro | 3582mAh | 100% | 3582mAh | 14% | 84% | 70% | 2507mAh |
| Richard | XCOOL | 15 Pro | 3274mAh | 91% | 2979mAh | 5% | 88% | 83% | 2473mAh |
| Ron | XCOOL | 14 Pro | 3200mAh | 83% | 2656mAh | 19% | 100% | 81% | 2868mAh (Proration from 75%) |
| Allison | XCOOL take 2 |
16 PRO | 3582mAh | 100% | 3582mAh | 17% | 92% | 75% | 2687mAh |
| Allison | XCOOL Steve’s |
16 Pro | 3582mAh | 100% | 3582mAh | 19% | 84% | 65% | 2328mAh |
Bottom Line
The bottom line is that whatever Qi2 charger you choose, don’t expect that the mAh rating is what you’ll actually get. Seems that something on the order of 50-70% of the rating is the best you can hope for. And Steve says I should apologize for fat-shaming the Apple battery pack by calling it chubby. I’m sorry.
I still like how slim the XCOOL battery is and it will definitely go in my backpack for conferences and whenever I’m near my grandchildren. Nothing burns a phone battery down faster than taking photos of grandchildren.