astro 220 and dc20 question

[jjfree]

I have 2 astro 220's and 2 dc 20 collars, my question is about the battery charge meter on the 220 it doesn't show the battery fully charged. I replaced the battery on one of the collars acct. it wasn't showing to fully charge up and it still does not show but 2 bars when fully charged (as per the blue light going off while chargeing) the other collar has the original battery and it aslo doesn't show but 3 bars when fully charged. Are these false indications on the hand held. So far they still work but am still testing them without charging them and they have both been used about 5 hrs. and still work and no battery dead indication. Has anyone had this same thing occur?