Can rarely usage of my prius c can cause problems ?

At some level, one reason the taxis go so far is that no one ever turns them off.

Your 12 battery should run at least once a week or you should consider a battery tender. Your Hybrid Battery should run once every 3 months or consider a Corolla.

(Philosophically, I do not understand buying a hybrid to let it sit. A Nissan Versa could sit as well)

 

50km once a week probably isn’t enough to charge the 12v battery back after week of sitting. So you probably need charger/tender. I’m with JimboPalmer that you probably would be better off with normal car if that is all the use it’s going to get.

 

That is maybe true for conventional car. 50m = 30mi or ~1hr, enough.

Agree with other comments if you drive so little Prius is overkill

 

ask a sales person at a toyota dealership.

 

Your 12 volt battery is likely to suffer, with a steady regimen like that. If you could go for a mid-week drive as well it'd help. I'd second getting a battery tender, some sort of "smart" charger, should be around 4 amp maximum. I'd recommend CTEK 3300.

Also, a digital voltmeter (cheap ones are around $20~30) will help you monitor the battery's status. A 12.6 volt or higher reading indicates a healthy battery. 12.4 level is "middle aged". 12.2 shows significant deterioration.

If you can't change your driving pattern, you might need need to hook up a charger (such as the CTEK) around the clock. There's no harm in that, it can't overcharge.

 

Except that on C you have to remove rear seat and plastics to get access to 12V battery. 20-30 min is enough to top off battery. I would not expect to battery last 6-7 years in such mode, but it should be fine for some time and it would be better off than on conventional car

 

^ Is there an under the hood jump point? Also, with the CTEK (and others) there's a short lead with pigtail connectors at one end, and connector for the CTEK charging cables at the other. You can hook up permanently to hard to access battery, run the lead out.

Personally I don't bother though, just connect up at under the hood jump point. Again, not sure if it's applicable on Prius c.

 

I have not looked but assuming 100mAmp draw, we are looking at 24*7=168hr, 168*0.1A = 16.8Ah.
Assuming 20A charge 1hr should be enough to recharge.

Now the numbers above are completely off the wall, I have not measured the draw on C. I could but too lazy to take off plastics. The other cars we looked at had ~50-100mA draw so my guess is as good as yours.

If I had to put battery on tender I would get a cheap ~$20 for motorcycle, made a hole in plastic and used connector cables which come with it for hooking. BUT IMHO it may be cutting close but not needed in this case.