Here are a few troubleshooting thoughts:
1) Check your charger contacts for film/debris. Use a pencil eraser to clean them. (This can be done on the charger and the battery.) If the charge light comes on and stays on consistently you know you have good contact.
2) Be certain your radio is shut off when on the charger.
3) New batteries sometimes need initialized. It will sometimes take 3 or more chargings to fully charge the battery. Check the date code of the new batteries to be certain what you obtained is truely new/fresh. Contact the vendor where you purchased the batteries and let them know of your difficulties in charging the new batteries.