A device for testing a battery, particularly a small, portable battery, comprising a flexible, transparent substrate on which is deposited a narrow band of {HEAD ~ a black light} absorbing {TAIL ~ material} 
A device for testing a battery , particularly a small , portable battery , comprising a flexible , transparent substrate on which is deposited a narrow band of { HEAD ~ a black light } absorbing { TAIL ~ material }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL