Prius Not Driven for 7 Months

Jump starting the Prius is very risky. Reversing the leads just once could total the car. I don't think that's a good option.

It probably need a new 12 V battery. But asking someone (who's not a S.O.) to do it would be far beyond the call of duty!

One little thing to try first--if the car has SKS, it can be turned off with a switch under the steering column. Ask your friend to look in the owner's manual and check that out. That will reduce drain on the battery.

If that's been done, or doesn't work, I would give your friend a break and reduce the visits to once a month, maybe. You may want to be sure the car is protected against rodents, and the tires stay inflated. And try to forget about it and enjoy your trip.

Welcome to the forum, and safe travels.

 

I'm on my 3rd Prius and have had 12v battery issues on the previous two due to it not being my primary driving vehicle. I would say that at this point, I would just wait until your return. You will likely have to replace the battery when you get back. If you don't want to do that:

• Make sure that the smart key system, if applicable, is not turned on
  • At the very least, make sure that the key is kept far away from the Prius while not in operation
• The car will need jumped and driven for quite a bit. I've not been impressed with the 12v battery management in the Prius when it has to choose between 12v charging and hybrid battery charging. It needs a drive of an hour or so and not 'turned on' in my opinion.

Safe travels!

 

Ditto above. I would reduce the jump start frequency to once a month for your friend or none at all. It isn't going to matter much to your engine to sit 10 weeks. The battery is more crucial but since it is dead, it hardly matters anymore.

 

Yes, the battery charging is very gentle and relies on the car being driven regularly to keep the battery charged up. However, it doesn't actually need to be driven to charge the battery, it only has to be in READY. Therefore it is not necessary to be driven for an hour or any other length of time; just being turn on (in READY) will suffice quite well. All that being said, (and presuming the battery is still serviceable), it would require that the car be left in READY for 12-16 hours to get anywhere near a full charge, again presuming it is currently flat, given it can't currently start the car.

I second the advice of the preceding posters that have advised to just leave the car as is, and deal with it when you return. More than likely you will need a new 12 V battery.