Interesting idea, but by going with this design of a spare battery with exposed contacts means you're going to have to do something with that extra battery if you want to fly anywhere, at least in the US (See the regulation: 49 CFR 175.10(a)(18) ). Personally I feel if you need that much spare charge, two separate banks would be the simpler and cheaper option.
Feels like this is entirely misguided on their part. Battery packs are bulk commodity items now, they've become cheap and ubiquitous. Everyone has their own branded ones out there. And with that in mind, I just don't understand an expensive version. Honestly, even in the corner case that you need so much juice that multiple battery packs are reasonable then I'd rather have another complete back with it's extra ports available. Sure, a little more bulk but only slightly and this gives me a truly redundant solution that I can lend to someone or have a complete spare in the event of loss or damage.
In the end, given that battery packs are already light and small making a lighter smaller one isn't that big a deal. Any thing in the 10k mAh range is too big to keep in a pocket all day anyway, and once you're tossing the things in a bag then it really doesn't matter if it's a little big smaller or lighter.
[quotemsg=19802041,0,441161]Any thing in the 10k mAh range is too big to keep in a pocket all day anyway[/quotemsg]
People stuff 6" 'phones' in their pockets. I've seen 10Ah power banks smaller than those but haven't tested one yet to see if they can actually deliver. I do plan to address that later this year.
Looking forward to seeing your tests on some of those smaller 10Ah ones you mention. I rarely need an on the go charge(my old Zen did sometimes when I forgot to charge it), but it is always nice to have 5 volts for testing things.
Phones have a bigger footprint but a 10k or 12k battery back is MUCH thicker and MUCH heavier. Take it from someone with a big phone AND a 12k battery pack; only one of those happily lives in my pocket all day. Maybe on something with cargo pockets you could stick the battery in a pocket but it wouldn't be comfortable to sit on it.
My battery pack is almost an inch thick dude; and totally inflexible and heavy enough that it can pull your pants down. It's a whole other kettle of fish compared to a phone, even a big phone.
I'll just shove this into my pocket with loose change...
They need some kind of spring-loaded safety cover for those contacts, and at that price I would want so much more than what they're offering. Standard cylindrical cells? I would expect it to be using fancier (and higher density) packs using semi-prismatic cells or maybe higher-end well-engineered pouch cells.. Maybe support for Qi charging and higher amp output / higher volt QC capabilities. Otherwise... it's really no better than a typical 5200 pack in the $30 range.
[quotemsg=19805518,0,441161]Phones have a bigger footprint but a 10k or 12k battery back is MUCH thicker and MUCH heavier.[/quotemsg]
That depends heavily on the type of cells being used and by type, I mean the actual chemistry and geometry of the cell which dictate the cell's maximum charge/discharge current, cycle endurance and nominal capacity. There is a drastic energy density difference between high current, high endurance cells (thicker current-carrying electrodes and anode/cathode material) and those prioritizing energy density over all else.
Also, a power bank designed around pouch-style cells isn't constrained by the size of 18650 cells and can be made much thinner.
[quotemsg=19805743,0,5190]I'll just shove this into my pocket with loose change...[/quotemsg]
Based on my limited short-circuit tests, that should actually be fine as the output cuts off within 2ms from the short being detected and wouldn't cause your change to warm up noticeably.
Still, I am disappointed that there wasn't some sort of protocol between the pack and frame to limit current until the connection to an accessory is confirmed.