Hi all, I'd love some insights into some problems I'm having with my daughter's 2013 Prius. She's been overseas for two months and I'm trying to take care of her car while she's gone. I have been taking it out for a ride every few days, for about 10-15 minutes. A few weeks ago it wouldn't start at all, was completely dead. I thought it might be due to the battery in the key fob so I replaced it but it still wouldn't start. I had someone jump start it, brought it to the mechanic, they said there was nothing wrong with it. They told me to try to drive it for longer amounts of time more often. Unfortunately, life and work got in the way and I wasn't able to take it out much more than every couple of days for 15 minutes or so. Today I went to start it and I couldn't even get the key fob to open the door. I opened it with the actual key and the car was completely dead once again, it wouldn't start. Once again I had it jump started. It took the jump and I drove it for a solid hour on the highway. I brought it home, parked it, and shut it off. Then I went back to it to see if it would start again. It flashed a red light that looks like a key light and said "key not detected". I put the fob right up to the power switch and got the car to start but I'm concerned that there's something wrong with either the fob itself or the car battery. I'm not sure where to go for help besides the dealership who I'm afraid will charge me a fortune. Any thoughts?
Hi Tabi'smom, Your problems are very likely due to the 12v battery discharging itself. Unfortunately, the Prius has a relatively small 12v battery since it isn't used for starting the engine like a normal "non-hybrid" car. A Prius 12v battery merely powers up the electronics and then the big hybrid battery is what spins the engine for ignition. Due to the small size, the 12v drains itself in about 6 weeks of low use/no use due to the small electronic devices it powers while the car is off. Driving the car for only an hour or so a week just isn't enough to keep it properly charged. If the car is parked at a location suitable for connecting a small battery charger, that could solve all your problems. Quite often, I've connected my 1.5 amp trickle charger to my second Prius just to keep the battery fresh. It sometimes can go months without being driven. You just need to remember to disconnect it prior to driving. I know that from personal experience!
Having the 12v battery consistantly die, is not good for the battery. Perhaps invest in a 4 amp battery charger and charge the battery for about 12 hours straight. That will give it a full charge. Maybe once a month charge it up again. If it won't hold a charge, or discharges quickly, it may be time for a new battery. You will likely have to charge it overnight because most places do not keep them charged up. A 1 or 2 amp trickle charger may help. You may have to remove the battery and charge it in your house. If you live in an appartment or have to park on the street. Also, how old is the battery? If it's 5 or more years old, it may need replacing.
Thank you so much. I don't drive a hybrid so I should have done more research before taking this car babysitting job on! My daughter will be home soon so I think I'll just try to use her car instead of mine until she returns so that I can keep the battery happy. But I'll recommend the small battery charger for her, that's a great idea. I really appreciate your help!
You might want to invest in one of those small jump packs. That will be able to get the car going if she gets stranded. But driving the car every day will certainly help.
I'm not sure when she last replaced the battery, I thought it was fairly recently though. I didn't want to ask her because I don't want to stress her out while she's away. I'm going to do the best I can to keep her car going until she returns and then I'll let her know what's been happening and that she should invest in a battery charger. If driving it every day until she returns doesn't prevent it from dying I'll need to get it to the mechanic to check the battery. Thank you so much!
Autozone or one of those places can check the battery for free. But they don't really understand what the 12v battery does in a Prius. It doesn't start the car, it just starts the computers. Just make sure no dome lights are on, and the doors and hatch door are closed completly. Hopefully, driving it daily will keep it charged enough.
