Possibly bad battery? Advice needed!

Let me start by saying with have a 2006 Prius with about 127,000 miles on it. We bought it used a few years ago, and up until now have had no problems with it or need for any repairs.

This past month we have noticed that the battery display shows that the battery drains quickly to two purple bars and then will rapidly recharge all the way back up to green in a few seconds. This has happened when first starting the car and also while driving. It has happened about 4 times in the past week or so, but we didn’t think too much of it at first. The weather is very cold here and we use the heat a lot. It also seems as if we are going through gas much faster.

Today on the way to the store we had to stop and get gas. After turning the car back on and beginning to drive a bunch of warning lights lit up, if I remember correctly it was the master light, an exclamation point in a circle, vsc and the engine light. We were really worried so we slowly drove the 10 minutes back home without issue. Once home we turned it off and let it sit, and when we turned it back on, just the master warning light and the engine light stayed lit.

I followed the instructions I found online to check the battery through the display menu. Hitting power once it showed the battery at 9V, hitting the power button a second time just brought up a blank display and then hitting power again while pressing the brake read the battery at about 14.1 V. Our closest Toyota dealership is about an hour away, so just driving that far and not knowing what it could be is rather scary.

Do you think the 12v battery going or is it the really expensive hybrid battery? Something else? Any help or info would be greatly appreciated.