HTC 3125 BATTERY / CRADLE WHATS NORMAL?

Question

JUST GOT A CRADLE FOR HTC 3125. NOTHING HAPPENS WHEN I PLUG IT IN NO LIGHT ON PHONE NO LIGHTS ON CRADLE CHANGE ....SO I TOOK BATTERY OUT AND PUT IN XTRA BAT SLOT ON BACK OF CRADLE AND THE LED ON THE CRADLE TURNED FROM GREEN TO RED...IS THIS NORMAL? OR DOES THIS MEAN THE BATTERY IS BAD? GOT THIS PHONE FROM A FRIEND TRYING TO DECIDE IF IT NEEDS NEW BATTERY OR IF SOMETHING IS WRONG WITH THE PHONE... OF COURSE THE CRADLE CAME WITH NO INSTRUCTIONS AS TO WHAT LIGHTS MEAN! :)