so you've left your phone plugged into
the wall all night you wake up with it
fully charged and ready for a full day
of selfies catching pokémon and selfies
of catching pokémon but just a few hours
in you get the dreaded low battery
warning and there's nary an outlet in
sight this is where portable battery
banks can save the day you just whip it
out of your pocket and bam no solar
panel or flashbacks to playing with a
scary jack-in-the-box to get the juice
you so desperately need but with all the
options out there how do you know which
one to pick well aside from the usual
reading reviews and checking
manufacturer reputations just as you
would do with a graphics card a webcam
or an extra-large hamster wheel the most
obvious place to start is with the
battery's capacity it's typically
expressed in milliamp hours which
despite the name is actually not a unit
of time so I just must hate us right but
rather a unit that describes the amount
of electrical energy a device can hold
so you can think of a device whose
battery is rated for fewer milliamp
hours like an iPhone has a cup of water
and a battery bank rated for more
milliamp hours as a bucket of water so a
battery pack with a high milliamp hour
rating can hold enough energy that it
can power up your devices
multiple times or powerup devices like
tablets with a higher battery capacity
themselves so consumer grade battery
banks start around 2,000 milliamp hours
and go all the way up to over 9000 these
devices at the higher end of that range
are capable of charging your average
smartphone eight times or even more but
if you've had a few of them you might
have noticed that battery banks with the
same milliamp hour rating can vary quite
a lot in terms of performance so what
gives for one thing not all batteries
discharged at the same rate all the time
this is especially true if you're
charging devices that draw a lot of
current
such as high-end tablets this lowers the
effective capacity to below what it
would be if you were just charging low
current electronics there's also more to
life than just battery size there are
features to consider in this video here
we compared five rugged battery banks
that advertised everything from built-in
LED flashlights to shock and water
resistance though it should be noted
that some of these claims didn't end up
panning out in the real world and while
we're on that subject there's more to
life than manufacturer's ratings for
capacity to line has published a video
that's me comparing how many times six
different brands of battery banks could
recharge an iPhone se and while most
reputable brands were within fifteen
percent of each other the worst one
tested was less than one third as
effective as some of the others and it
doesn't get easier charging rate going
back to our water analogy is how quickly
you can pour from your bucket to your
cup and is a huge factor for folks who
want to plug in for 20 minutes while
getting ready for that big date and not
have to carry their charger around for
the rest of the night typically battery
banks have either one amp or two amp
outputs both of which are running at the
standard USB 5 volts if you have a
device that can accept two amps of
current as many newer ones can then a 2
amp output on your battery bank will not
only charge your device faster but it
will also keep it running if you need to
use it while it's charging keep in mind
though that chargers labeled as 4.8 amp
or some other high number are usually
referring to total current across all of
the port's which is great if you're
going to be plugging in multiple
power-hungry devices at once if the
regular USB spec isn't enough for you
though there are even some battery banks
that support rapid charging technologies
like Qualcomm quick charge and Samsung
fast charge that can power up your
devices even more quickly by increasing
from 5 volts up to as high as 20 volts
but those require both a device and a
charger that support
now go forth with this knowledge and
find yourself a battery bank that gives
you all the power you've ever wanted
just don't use it to try and invade
Russia in the winter time we all know
how that works out ,