You're probably right about them being only
slightly valuable but it's
still interesting to look at. Most people today have nver seen the inside
of a battery and have no idea what they look like. This battery was built
by Willard. I took a picture today and posted it at
<http://www.classiccmp.org/hp/battery/willard.jpg>.
Congrats - you found one of the better batteries. Three of these fit
inside a CY-77/PPN-1 battery box for the AN/PPN-1:
http://users.bestweb.net/~toober/images/CY-77_PPN-1A.open.jpg
AN/PPN-1s are quite valuable ($3500 typical), but few collectors pay much
for the batteries - who wants to lug around three heavy batteries in a
closed box when playing soldier? Still, you could probably get $25 to 50
for your unit.
William Donzelli
aw288(a)osfn.org