Another Idea｜Key Chain Battery Tester｜ Other Products

This self-contained battery tester is also a battery holder AND a key chain. Carry in pocket or purse to test if your battery is weak, dead, or at full power.
Features

Self-contained battery tester
Convenient for pocket or purse
Tests sizes 13, 312 and 675 (NOT compatible with size 10) 
Red light emitted to show battery life 
Storage compartment for 2 extra batteries 
Quick and easy to use 
Brand:ADCOSKU:3104Tags:Battery Accessories, Battery Testers, Ear Care & Hearing Aid Supplies, Hearing Aid Supplies, Magnets & Accessories, Small Item