8/15/2019 Battery Calibration
1/1
Battery discharges
FuU
battery ct
rscharges (
u.n til
laptop po
we
r
shutd
own. 0%} sho u'ld
be
r----------------- '1
a v o
because
th
is
stresses t h ~
battery
a lot and can even damage
t. It 's
recommen
ded to
perf
orm
part
ial
ct
rscharges to
capacity
levels o f
20
'
30% and frequent charges, instead o f performi
ng
a
fuJI
ctrschargi
ng
foJiowed by a
fu
.8
charg
i
ng,
Laptop batteries c o
nta
in a
capacity
gauge that
a lows
us
to
kn
ow
the
exact amount o f eMrgy
st
ored. However. d ue to the
charg
i
ng
/ctSCharg i
ng
cycles, t his
sensor tends
to be inaccurafe overtime.
Some
laptops include in the ir BIOS
to o
k to recatibrate this
battery
gauge, which
is
nothi
ng more
than a
fu U
discharge
followed
by
a fu fl c h a r g ~ .
So
to ca librate
the
gauge. it sho u.Jd
be perfor
med, in
v ry
30 ctrscharge
cycles,
a
full
discharge non-stop . followed by a
also
. no
n-st
op, fu U
charge.
An i
naccurate
gauge can lead to the fact that the the
battery
capacity va l
ues
are are w
rong.
The
battery may
report that it
st
ill
has
10% o f
capacity
w
hen
in fact it
has
a much lower val
ue, an
d this causes the com
puter
to
shut
down
unexpectedly
.
Discharge (or
charge)
cycles co nsist o f usi
ng
aD
that
battery
charge {100%) but not necessarily aft at
o nce.
For exam
pje. yo
u can
use
t h ~ la
pt
o p for
some
minutes in a day, usi
ng
hatf
its
capacity then
fu
lly charge
it.
If you ctd the same th i
ng
in the next day, it wouJd be co unted a
d 'ISCharge cycle and no t t
wo,
so
it
may take
se
veral
days
un
til a fu
U
discharge cyde
is
completed.
How to perform a calibration (full discharge)?
The
most adequate
method to do a fu UCISCharge (100% to a minimum o f 3%} co
nsists o f the followi
ng procedure
:
1. Fully charge the
batter
y to its maximum capadty ( 100 );
2
Let the battery •rest• fully charged for 2 hours or more in
order to cool down from the charging process. You may
use the computer normally within this period;
3
Unplug the power cord and set the computer to hibernate
automatically at 5 as described
by
the image
sequence below (dick images to enlarge) .
f
you cannot select
5
, then you should use the minimum value
allowed ,
but ne
ver below 5 ;
... =::::._-.=::...-
-
-
~ ~
4 le ave the computer discharging, non-stop, until
i t
hibernates itself. You may use the computer normally within
this
period;
5 When the computer shuts down completely, let t stay in the
hibernation state for 5 hours or even more;
6. Plug the computer to the A/C power to perform a full charge
non-stop until its maximum capadty { 100 ) . You may
use the computer normally within this period.
f t ~ r the calibration
process
the reported wear level
is
usualty high r
than
before. Th.is
is
n a t u r a since it now
reports
the
tru
current capacity
that
the
battery has
to hold charge. Lithium Jon batteries have a nmit am ount o f
d'rscharge cydes
(generally 200
to
300
cycles
) and they
wiD reta
in kss capacityov rtime,
t·1any people tend to th i
nk
calibrating g iv
es
high r wear level. then it's a
bad
thi
ng
*. This is w rong,
because
tike said,
th
calibration is meant
to
have your
battery
report
th
true
capacity
it
can
hcld,.
an
d it's meant
to
a vOO surprises Uke, for
examp
le..
being in the middle
of
a presentation and
sudden
ty the com
puter shuts
down at 30% o f
charge.
