The new version of the American
AN/PAS-13 thermal sight is a wonder to behold, as it enables infantry to see
through darkness, mist and dust storms, because it can make out differences in
heat. But these useful devices have a downside, they go through batteries at a
prodigious rate. The AN/PAS-13 actually comes in three sizes, to accommodate
longer ranges of some weapons. The smallest one, weighing 1.8 pounds, is used
on your basic M-16 or M-4 assault rifle. This sight has a range of 550 meters,
uses 4 AA batteries (lithium, as used in cameras). That gets you about 5.5
hours of use. These batteries weigh about twenty per pound and cost the
government about $1.50 each. Now consider that your average infantry battalion
will have several hundred of these sights. Do the math. It adds up. On many
operations, a unit will use more batteries than ammo. These batteries are
slightly heavier, and four times more
expensive, than 5.56mm rifle ammo.
The next version weighs 2.8 pounds, has a range of
1,100 meters and is used in 5.56mm and 7.62mm machine-guns. This sight requires
six AA batteries (for 6.5 hours). The heaviest version weighs 3.9 pounds, has a
range of 2,200 meters, and is used by heavy machine-guns and snipers. This one
also requires six AA batteries (for 6.5 hours).
When possible, the troops try to rely on the
thermal sights in armored vehicles, as these run off the vehicle electrical
system, and can go all night without worrying about any battery issues.
The new version of the sight will start showing up
in Iraq and Afghanistan by the end of the year. Unless there is a much improved
new version in the next few years (no one is sure, engineers can be
unpredictable), the army plans to buy as many as 150,000 AN/PAS-13 sights (at a
cost of over $10,000 each). Battery cost not included.