<s>
A	O
battery	B-Algorithm
grip	I-Algorithm
is	O
an	O
accessory	O
for	O
an	O
SLR/DSLR	O
(	O
and	O
occasionally	O
other	O
cameras	O
)	O
,	O
which	O
allows	O
the	O
camera	O
to	O
hold	O
multiple	O
batteries	O
to	O
extend	O
the	O
battery	O
life	O
of	O
the	O
camera	O
,	O
and	O
adds	O
a	O
vertical	O
grip	O
with	O
an	O
extra	O
shutter	O
release	O
(	O
and	O
other	O
controls	O
)	O
,	O
facilitating	O
the	O
shooting	O
of	O
portrait	O
photography	O
.	O
</s>
<s>
Most	O
battery	B-Algorithm
grips	I-Algorithm
also	O
come	O
with	O
a	O
second	O
cassette	O
allowing	O
the	O
photographer	O
to	O
shoot	O
using	O
multiple	O
AA	O
batteries	O
.	O
</s>
<s>
Battery	B-Algorithm
grips	I-Algorithm
are	O
usually	O
designed	O
to	O
fit	O
only	O
one	O
or	O
a	O
few	O
specific	O
camera	O
models	O
,	O
since	O
they	O
must	O
match	O
the	O
body	O
's	O
shape	O
,	O
connectors	O
,	O
and	O
power	O
requirements	O
.	O
</s>
