[![Thumbnail](https://images.dlive.io/a0f3048e-82cf-11e8-ba94-0242ac110002)](https://dlive.io/video/molometer/40b58fa0-82cc-11e8-bbe8-435b8d3c86e8)

In the last few weeks I have had some problems with the Prius 12 volt battery going flat so five days ago I had figured out a way to resolve some of these issues. 
The Prius mark 1 (generation 1) that I have is almost an antique and so I began to think that maybe it's just getting old.  

But it turned out that the age has nothing to do with it. It is to do with the amount of work it is doing or not as the case may be. 
We have another Prius which I use more often as it has AC in this hot weather. Also I am a semi retired teacher and so the car doesn't get used every day and can sit for many days without being used at all.

The 12 volt battery in the boot which runs the computer, central locking and alarm system is pretty small. Little bigger than a motorbike engine and so discharges pretty quickly if it is not used.

As I explained in the [last Dlive video](https://dlive.io/video/molometer/44b7eac0-7dfa-11e8-bbe8-435b8d3c86e8) The Prius has no alternator but rather it charges the 12 volt battery from the main traction engine and while coasting and braking and it charges up really fast as you can see in this video.

I took it for a 10 minute drive and the battery was back to full power.

What's the lesson here?

Use it or lose it. Basically if you do not use the car on a regular basis then you have to make arrangements to keep the battery topped up by for example using a battery maintainer like this one. [Battery maintainer](https://amzn.to/2KQQApZ)

I have one of these that I usually put on the car when I leave it at the airport when going on a long trip (5 weeks+) and when I return the car is fine.

Sitting outside my house I didn't think to put the maintainer on to keep the battery charged up? It seemed like a load of faff to me as you never know when you are going to pop out somewhere. Then you have to unhook the battery maintainer etc. Faff!

I've never had many problems with the Prius but lack of use. It really doesn't like.

Hope this helps you with your hybrid folks. I know it's a bit of a niche topic but niches can be useful too. 

My video is at [DLive](https://dlive.io/video/molometer/40b58fa0-82cc-11e8-bbe8-435b8d3c86e8)