CES 2015: ibattz Claims Upcoming Power Banks Will Fully Charge in 15 Minutes [Updated]

Imagine I give you an 8oz glass, and keep a 24oz glass for myself. We pour 8oz into both glasses at the same rate.

Are you better off for being "full" while I still have room for 200% more ... ?

We both reached 8oz ... at the same time.

I like the visual analogy, but that is not analogous to how batteries work.

For simplicity and to borrow your numbers, let's say we have two batteries with capacities of 8 and 24. The closer each battery gets to full, the slower it charges (exponentially slower, it has to do with potential and resistance).

The 24 battery will get to 8 much faster than the 8 battery will get to 8. The 8 battery starting at 0 might take 5 minutes to get to 2, 10 more minutes to get to 4, 20 more minutes to get to 6, and 40 more minutes to get to full 8. Meanwhile, the 24 battery starting at 0 might take 5 minutes to get to 6, 10 minutes to get to 12, and so on; it will reach 8 much quicker because at 8 it is only 33% full and there is still a lot of potential with little resistance.

A better water analogy is this: picture two tubes of the same diameter, sealed at the top, one is 8ft tall and one is 24ft tall, both being filled from the bottom with same input nozzles of same flow rates. As the tubes fill, the air at the top gets compressed and pushes back on the water and slows the rate of filling. Because the 24ft tall tube has more air at the top, the rate will slow down less over the first 8ft. When the 8ft tube is nearly full, it has nearly 8ft of air compressed into a tiny bubble at the top. When the 24ft tube has 8ft, it has 24ft of air compressed into a 16ft space.

One often overlooked feature of a smaller battery is the ability to charge the small battery fast.

Imagine I give you an 8oz glass, and keep a 24oz glass for myself. We pour 8oz into both glasses at the same rate.

Are you better off for being "full" while I still have room for 200% more ... ?

We both reached 8oz ... at the same time.

oneMadRssn: Sounds like the initial "at least a smaller battery charges faster" comment is even more wrong that I realized!

If they're talking about a 5V 1A input, aren't they referring to how quickly the power bank charges up from the mains?

Mind you this is coming straight out of the press release. Presumably ibattz will want to shop for a better PR agency next year.

I never knew there were so many Ph.Ds specialising in battery engineering on these forums.

Am I missing something? Wouldn't the rate be limited by the iPhone? Last I checked I don't get 100% in 15 minutes even using the iPad 12W 2A adapter...

Their press release was totally wrong/misleading. We've added an update to our post.

I'm always skeptical of something that charges really fast. I used to use those Rayovac batteries with the 15 minute charger and those things would be trashed in no time. You would think you're actually saving money but in many cases the opposite was true. Batteries are very finicky and need to be conditioned over time. Actually I've turned into quite the battery snob…

If anyone is interested, today I have a PowerEx C9000 charger/analyzer that I really like. You can set the charge rate yourself and even recondition batteries and analyze their power output. I use Eneloops with them and it's the perfect combo. I got around my need of a 15 minute charger by just buying a ton of Eneloops and having some ready to go. Eneloops keep their charge for a ridiculously long time, so I get these little cheap battery magazines on Amazon and when the batteries are dead I put them back in but upside down so I know which ones I need to charge the next time I'm home. If anyone here uses high-powered flash units quite often they also have a line of Eneloop Pros that recycle quite quickly. Eneloops are pricier but I've never had to replace one and I've been using them for several years now. If one starts dipping in capacity I just use the PowerEx to recondition it and it's good to go.

Glad they updated the article for clarification. The iPhone 6 and 6 Plus only charge at two rates. One is fairly slow at regular iPhone rates and one is faster at iPad charging rates. That's it. There is no other rates available to the hardware to charge quicker.

I'm always skeptical of something that charges really fast. I used to use those Rayovac batteries with the 15 minute charger and those things would be trashed in no time. You would think you're actually saving money but in many cases the opposite was true. Batteries are very finicky and need to be conditioned over time. Actually I've turned into quite the battery snob…

If anyone is interested, today I have a PowerEx C9000 charger/analyzer that I really like. You can set the charge rate yourself and even recondition batteries and analyze their power output. I use Eneloops with them and it's the perfect combo. I got around my need of a 15 minute charger by just buying a ton of Eneloops and having some ready to go. Eneloops keep their charge for a ridiculously long time, so I get these little cheap battery magazines on Amazon and when the batteries are dead I put them back in but upside down so I know which ones I need to charge the next time I'm home. If anyone here uses high-powered flash units quite often they also have a line of Eneloop Pros that recycle quite quickly. Eneloops are pricier but I've never had to replace one and I've been using them for several years now. If one starts dipping in capacity I just use the PowerEx to recondition it and it's good to go.

Aaah, eneloop, best you can get, I also use them in all of my gear.
And, they aren't that much more expensive if you can find a good reliable seller on the internet.