Replace battery doesnt work in UK??

hiya, i bought a replace battery - SIDO Li-12B, 3.7V 1150mAh for my Sanyo DC in HONG KONG. i don't understand how come it worked in HK, but not in UK and USA.
i tested it in hk, but once i left and arrived in USA and UK 3 weeks later, it doesn't work.
well, the light on the battery charger is twinkled with red light when i place the new battery, but green for the old one.
does this make sense to u?
cheers!!!