Cellboost instant battery charger for cell phones
disposable battery charger comes in different models, each
different plug to fit a different type of cellphone.
They are very easy to
use - just plug them in to the phone. They are also
- street prices of about $6 each.
Best of all, they work
as promised, giving 60 minutes or more of extra talk time,
and up to 60 hours of standby time.
Unfortunately, they're also limited to only a single
use. Our own
Clipper Gear Cell
Phone Emergency Battery Recharger is probably a better
choice for most people and situations.
Now you no longer need to be
always charging your cellphone, even when the battery is still
Just slip one of these small and inexpensive Cellboosts into your pocket and you're protected if your battery
dies on you.
What you get
Cellboost is packaged
on a plastic card, but mercifully it is easy to open and get it
out - there are perforated tear lines on the back of the display
The unit measures slightly
over 1¼" x 2", and is just under ½" thick.
A protective cap (color
coded for different phone types) protects the plug that sticks
out of the top of the unit, and brings the total length of the
unit up to about 2¾". Each unit weighs a negligible 1¼
ounces - you could fill your pockets with these and not notice
There are almost no
instructions with the unit (and no real need for instructions,
either), other than a suggestion to wait two minutes before
turning on a cellphone if its battery is completely dead, and to
unplug the Cellboost after 60 minutes.
Each unit shows an
expiration date on it. The several that I got in early
2003 all showed a
September 2006 expiration, suggesting that the batteries inside
the Cellboost units last about 2.5 - 3 years.
How it Works and What it Does
Plug the Cellboost unit into
the charger socket of your cell phone, and it starts
transferring its charge from its internal (non-rechargeable)
batteries into your cell phone.
I tried Cellboosts with
three different brands of phone and type of plug (Siemens, Nokia
and Motorola). In all cases they plugged easily and firmly
into the phone's charger socket, making it possible to use the
phone while the Cellboost was plugged in to it, so you can start
using your phone again within seconds of plugging in the
The display card boldly
states the capacity of the Cellboost unit, giving 60 minutes of
talk time or 60 hours of standby time. A small asterisk directs
you to the necessary fine print which explains that these are
average times, based on phone model and optimal conditions.
This made me very skeptical.
I've never yet bought a cellphone that actually has as much
battery life as the manufacturer claims, and this 'optimal
conditions' phrase reminded me strongly of claims by
FRS and GMRS radio manufacturers about
their range capabilities - claims that my testing showed to
be exaggerated almost ten-fold in non-optimal conditions!
So, with considerable
curiosity, I set about testing these units, expecting results
way below the stated claims.
Test 1 - Nokia 3650
I discharged my
Nokia 3650 until the battery
was so dead that the unit switched off and wouldn't restart.
I then plugged in a
Cellboost unit. With the phone still switched off, I
charged it for two minutes, then turned the phone on, and placed
a phone call.
I left the Cellboost
connected into the bottom of the phone, and timed to see how
long I could talk on the call before the battery died on me.
The signal strength for the
T-Mobile GSM service I was using varied between 2/3 and maximum
as I moved the phone around a bit, to try and create a realistic
use environment. I also had the phone's Bluetooth switched
on (this drains the battery faster than if it is off).
After 52.5 minutes, the
This was more than
satisfactory, and closer to the claimed optimum performance than
I've ever experienced with cell phone batteries before.
But, wait - there's more!
Although the Cellboost
instructions said not to leave their battery plugged in for more
than 60 minutes, I left it plugged in, with the phone off.
After 12 minutes, I turned the phone back on again, and made
Incredibly, the phone lasted
another 27.5 minutes before the battery died and the call was
disconnected. This made a total of 80 minutes airtime,
using a phone that chews through battery life at a rapid rate.
And, I'm still not done.
I still had the Cellboost
plugged in. After 5 minutes of charging the dead phone, I
turned the phone back on. At this point, the phone told me
it was no longer getting any more charge from the Cellboost
unit, so I unplugged it. The phone continued to work on
standby for another 30 minutes before I gave up waiting for it
to die again.
better than expected.
Test 2 - Nokia 3650
I took my fully discharged
3650 and recharged it again with a Cellboost, leaving the
Cellboost connected to the phone for an hour. Then, in an
attempt to recreate a typical day of usage, I made several short
calls with periods of standby in between.
I was able to get 10 hours
of standby time and 16 minutes of talk time out of the charge
from the Cellboost.
The good news - this is
probably enough to get you through the rest of a day until you
can get to a charger if your phone dies on you early in the
morning. But it seemed to be rather less than the 60
minutes or 60 hours promise indicated.
Test 3 - Motorola V66
I discharged the battery in
my V66 until it was so dead that I couldn't turn the phone on.
I then plugged the Cellboost
unit into it, waited two minutes, and then turned the phone on
and made a call.
My test with the 3650 was
intended to be a tough test - with only fair signal strength
(the weaker the signal, the more power is used to send out the
radio transmissions). And the Nokia 3650 was set to use a
lot of power, more than most other phones would. Even so,
in this tough environment, I got 80+ minutes of talk time.
I now decided to make the
V66 test a 'best case scenario' - the lovely tri-band V66 that I
is a very light power user, and so I expected it to last at
least an hour and maybe even more.
I left the phone in an area
with perfect T-Mobile GSM reception, and turned off all the
other current draining features of the phone.
You'll remember that
Cellboost promise 60 minutes of talk time in optimum conditions.
Guess how long my V66 call lasted before the battery died?
Not 50 minutes. Not 60
minutes. Not 90 minutes and not 120 minutes. I got a
staggering 155 minutes out of the call!
This is amazing. A
device that is 250% better than the manufacturer claims!
However, while the Cellboost's performance is very credible, the
Recharger provides more than twice as much power and so
gives better emergency backup.
Facts and figures
With a new Cellboost unit
(for my 3650) I measured its voltage. Fresh, the unit was
giving off 6.33 volts, and when first connected to the phone
with a nearly flat battery, it was pumping about 350 mA of power
into the phone.
Both voltage and current
rapidly dropped off, within three minutes only 250mA of current
was flowing into the phone, and after 7 minutes it dropped to
150 mA, a level that stayed reasonably constant for the future.
By the time the Cellboost
had just about all the charge sucked out of it, the voltage had
dropped down to 4.83 V.
The standard Nokia wall
charger feeds in power at a much greater 795 mA, at a notional
6V. This discrepancy is a good thing - it means that the
Cellboost units are not harming the expensive battery inside the
cell phone; a fact that I also empirically confirmed by checking
that the phone's battery didn't get at all hot (heat buildup
during charging means you are seriously harming your
Getting the most from your
The batteries inside the
Cellboost recover some of their strength after they have had a
break from charging your cell phone.
The best idea is to charge
your phone with the Cellboost for about 20 minutes. This
will probably transfer about half the power from the Cellboost
to the phone. Then, when the phone dies again, plug in the
Cellboost unit again, and after another 20 minutes, you'll have
transferred perhaps half of the remaining half charge.
And so on. In a total
emergency, even a completely dead cellboost unit, that can no
longer charge a phone, will still recover a small amount and
give a precious minute or two or three of power before dying
once more. But normally, you'll probably choose to replace
your Cellboost after a couple of short (20 minute or less)
A look inside the unit
Reading the publicity
materials supplied by Cellboost, I came across the statement
Cellboost has a unique
means of instantly providing talk time and charging for
This intrigued me. A
'unique means'! Although the instructions warned not to
open the unit, I fearlessly went ahead and opened up a Cellboost to
see what unique technologies were inside.
Ummm. There were four
small batteries joined in series (to provide the power) and a 2
ohm resistor also in series (to provide a simplistic and
inefficient voltage control). Nothing else.
Unique? No. But,
the simplicity of the unit is not a bad thing, and in no way
detracts from its functionality.
The Cellboost units
generally cost the
same, no matter which model type you get (the only difference is
the adapter on the top, which varies to fit the different cell
phone charger sockets). I've seen them for sale as low as
$6 each at
PCMall.com. They're also available at a growing number
of electronics and phone retail outlets.
Sometimes your cell phone
can be an essential tool to help you resolve an urgent problem.
At such times, you can't afford to have your battery die on you.
For only about $6 each,
carrying a Cellboost with you means that, no matter what else
might be going wrong around you, there is no danger that your
cell phone will die. You'll get enough extra battery life
to spend an hour (or perhaps more) on the phone, or to have a
mix of talk time and standby time for close on an entire
The Cellboost is small and
light, simple and inexpensive, and works perfectly. On the
other hand, you need to have different Cellboosts for every
different type of cell phone you might have in your office or
family, and after using them once, you need to throw them away
and replace them.
Emergency Cell Phone Recharger uses inexpensive AAA
batteries, and has multiple adapters for different phones,
making it generally the better choice for most people and
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23 January 2004, last update
21 Jul 2020
You may freely reproduce or distribute this article for noncommercial purposes as long as you give credit to me as original writer.