Nice round up of battery packs for keeping your devices running - sometimes for several days. (And one for $16!)

external (spare) batteries for phones, laptops and other devices

TRO

It's a shame external phone batteries generally only last 2-3 years.

I haven't figured out what's best for me yet. I like mine external battery chargers because they can charge while using the phone, but a spear battery is much smaller...

It's a matter of charge cycles as well as age. Also, they tend to gradually lose capacity with usage and time. Larger capacity batteries, in my experience, tend to be useful longer.

That's the downside of lithium ion and lithium polymer technology and low cost cells. They are typically made to a 300 cycle MTBF but remember they also loose a %of capacity no matter how they are used or not used. I've seen some higher end that last a little longer but your going to pay more.
That's one reason I stick with AA powered devices when possible.

I think I've linked to it before, but this is why on my long list of things I should do is making a Minty Boost charger.



I like the idea of being able to use AA's to recharge devices with internal batteries if needed.

I think there are commercial versions out there too, but building it seems like more fun .

Edited to add: here is a commercial version of this concept from Energizer which uses 3 AAs: Instant Charger

If your device has removable battery a charged spare battery is much smaller/lighter. An external pack needs to convert its internal lithium ion voltage 4.2v to USB 5v, then your device convert it back to 4.2v. You lose a lot of power in the process so you only get about 2/3 of the pack capacity.

I dunno. One potential problem is that, as soon as they change the connector on whatever device you wanna charge, your external power supply may suddenly become obsolete.

My best external battery pack is under the hood of my truck and starts the motor and is good for thousands of recharges. And when they change the connector on my device, I just get another charging cable.

sotto,

A little hard to carry in your pocket though! :-)

Respectfully,

Jerry

They are supposed to stick with microusb on the phone side for a while, but a USB to supermicroUSB cable will be easy enough to replace when they come out with it.




I have two of those under my hood, one is none and two is one right

I have this one, carry with 4 eneloops inside.

http://www.verbatim.com/subcat/accessories/power-pack-chargers/aa-power-pack/products/