Blinking back up battery light.

I have had U-verse since about 2009 or 2010. When we started out we had the bundle with the TV, phone, and internet. Now we just have U-voice and the internet. I've noticed lately that I have had interrupted U-voice and internet service. After having several techs come out the problem seemed to be fixed. After the last tech came out and re routed my U-verse internet to a more stable line (according to them) I have noticed that the belkin BBU box battery light is blinking red. I have unplugged it and plugged it back in and it doesn't even sound the alarm anymore. Would this mean I need to buy a replacement battery? I have looked into them and found them via AT&T's support page but I thought I'd ask first.   

Thanks for the help everyone.