<s>
Memory	B-Algorithm
effect	I-Algorithm
,	O
also	O
known	O
as	O
battery	B-Algorithm
effect	I-Algorithm
,	O
lazy	B-Algorithm
battery	I-Algorithm
effect	I-Algorithm
,	O
or	O
battery	B-Algorithm
memory	I-Algorithm
,	O
is	O
an	O
effect	O
observed	O
in	O
nickel-cadmium	O
rechargeable	B-Architecture
batteries	I-Architecture
that	O
causes	O
them	O
to	O
hold	O
less	O
charge	O
.	O
</s>
<s>
This	O
long-term	O
,	O
repetitive	O
cycle	B-Algorithm
régime	O
,	O
with	O
no	O
provision	O
for	O
overcharge	O
,	O
resulted	O
in	O
a	O
loss	O
of	O
capacity	O
beyond	O
the	O
25%	O
discharge	O
point	O
.	O
</s>
<s>
In	O
one	O
particular	O
test	O
program	O
designed	O
to	O
induce	O
the	O
effect	O
,	O
none	O
was	O
found	O
after	O
more	O
than	O
700	O
precisely-controlled	O
charge/discharge	B-Algorithm
cycles	I-Algorithm
.	O
</s>
<s>
In	O
a	O
follow-up	O
program	O
,	O
20-ampere-hour	O
aerospace-type	O
cells	O
were	O
used	O
on	O
a	O
similar	O
test	O
régime	O
;	O
memory	B-Algorithm
effects	I-Algorithm
were	O
observed	O
after	O
a	O
few	O
hundred	O
cycles	O
.	O
</s>
<s>
Phenomena	O
which	O
are	O
not	O
true	O
memory	B-Algorithm
effects	I-Algorithm
may	O
also	O
occur	O
in	O
battery	O
types	O
other	O
than	O
sintered-plate	O
nickel-cadmium	O
cells	O
.	O
</s>
<s>
In	O
particular	O
,	O
lithium-based	O
cells	O
,	O
not	O
normally	O
subject	O
to	O
the	O
memory	B-Algorithm
effect	I-Algorithm
,	O
may	O
change	O
their	O
voltage	O
levels	O
so	O
that	O
a	O
virtual	O
decrease	O
of	O
capacity	O
may	O
be	O
perceived	O
by	O
the	O
battery	O
control	O
system	O
.	O
</s>
<s>
A	O
common	O
process	O
often	O
ascribed	O
to	O
memory	B-Algorithm
effect	I-Algorithm
is	O
voltage	B-Algorithm
depression	I-Algorithm
.	O
</s>
<s>
To	O
the	O
user	O
,	O
it	O
appears	O
the	O
battery	O
is	O
not	O
holding	O
its	O
full	O
charge	O
,	O
which	O
seems	O
similar	O
to	O
memory	B-Algorithm
effect	I-Algorithm
.	O
</s>
<s>
This	O
is	O
a	O
common	O
problem	O
with	O
high-load	O
devices	O
such	O
as	O
digital	B-Device
cameras	I-Device
and	O
cell	O
phones	O
.	O
</s>
<s>
Voltage	B-Algorithm
depression	I-Algorithm
is	O
caused	O
by	O
repeated	O
over-charging	O
of	O
a	O
battery	O
,	O
which	O
causes	O
the	O
formation	O
of	O
small	O
crystals	O
of	O
electrolyte	O
on	O
the	O
plates	O
.	O
</s>
<s>
This	O
effect	O
is	O
very	O
common	O
,	O
as	O
consumer	O
trickle	B-Algorithm
chargers	I-Algorithm
typically	O
overcharge	O
.	O
</s>
<s>
Nickel	B-Device
–	I-Device
metal	I-Device
hydride	I-Device
batteries	I-Device
,	O
for	O
example	O
,	O
are	O
known	O
to	O
experience	O
this	O
form	O
of	O
capacity	O
loss	O
often	O
mistakenly	O
attributed	O
to	O
memory	B-Algorithm
effect	I-Algorithm
.	O
</s>
<s>
The	O
effect	O
can	O
be	O
overcome	O
by	O
subjecting	O
each	O
cell	O
of	O
the	O
battery	O
to	O
one	O
or	O
more	O
deep	O
charge/discharge	B-Algorithm
cycles	I-Algorithm
.	O
</s>
<s>
Some	O
rechargeable	B-Architecture
batteries	I-Architecture
can	O
be	O
damaged	O
by	O
repeated	O
deep	O
discharge	O
.	O
</s>
<s>
The	O
resulting	O
loss	O
of	O
capacity	O
is	O
often	O
ascribed	O
to	O
the	O
memory	B-Algorithm
effect	I-Algorithm
.	O
</s>
<s>
Battery	O
users	O
may	O
attempt	O
to	O
avoid	O
the	O
memory	B-Algorithm
effect	I-Algorithm
proper	O
by	O
fully	O
discharging	O
their	O
battery	O
packs	O
.	O
</s>
<s>
All	O
rechargeable	B-Architecture
batteries	I-Architecture
have	O
a	O
finite	O
lifespan	O
and	O
will	O
slowly	O
lose	O
storage	O
capacity	O
as	O
they	O
age	O
due	O
to	O
secondary	O
chemical	O
reactions	O
within	O
the	O
battery	O
whether	O
it	O
is	O
used	O
or	O
not	O
.	O
</s>
<s>
Unfortunately	O
the	O
number	O
of	O
operational	O
cycles	O
is	O
still	O
quite	O
low	O
at	O
approximately	O
400	O
–	O
1200	O
complete	O
charge/discharge	B-Algorithm
cycles	I-Algorithm
.	O
</s>
<s>
The	O
lifetime	O
of	O
lithium	O
batteries	O
decreases	O
at	O
higher	O
temperature	O
and	O
states	B-Algorithm
of	I-Algorithm
charge	I-Algorithm
(	O
SoC	O
)	O
,	O
whether	O
used	O
or	O
not	O
;	O
maximum	O
life	O
of	O
lithium	O
cells	O
when	O
not	O
in	O
use(storage )	O
is	O
achieved	O
by	O
refrigerating	O
(	O
without	O
freezing	O
)	O
charged	O
to	O
30%	O
–	O
50%	O
SoC	O
.	O
</s>
