We will be taking ownership of a new 2010 Prius II in a day or two. The deal has been made, a deposit has been given, and leather seats are being installed. My voiced my concern about long-term storage of the Prius (six months over the summer in FL) to the service manager. He told me to disconnect the 12 volt battery and that the traction battery would be fine for that length of time. After reading some of the threads and posts, I am not sure the service manager was giving me the correct information. Can anyone tell me if the rate of discharge on the traction battery will cause problems due to a six month storage in warm/hot temperature? Should I be concerned because it is warranteed for 10/100,000?
I confess I would not have recommended you buy a Prius you did not intend to drive. The long battery life in the big city taxis is, in my opinion, due to them rarely being turned off, they drive 24/7. Time spent off is time spent without the computer nannys keeping the battery healthy. I seriously doubt anyone has a 201 volt trickle charger for the HV battery. All that being said, Toyota will honor their warranty.
The self discharge rate on the HV battery is very low. Just make sure you have at least a mid level SoC before putting it in storage. Tom
Easy way to do this is just start the car up in a morning and let it warm itself up (maybe put the heating on so it'll run longer?). As its running it will also start charging the HV battery and will stop once the charge level is one bar from top (the top bar only comes on after long downhill runs). The HV battery should now be as charged as it'll get. But as others have said, you will need to disconnect the 12v battery if storing.
Basically, anything that you do to try to maintain your HV battery, i.e. 200 VDC float charger, will void your warranty from Toyota's point of view. Long term storage will not hurt it, the main risk is that the voltage will be too low to start it when you come back. In such a case it would be covered under warranty. Now, I do think that you should hook up a Battery Minder to your 12V. Even when disconnected, these stupid little things will sulfate and die, especially in the hot/humid Florida summer.
Just had to comment from the future on this, it seems that having a "Nanny Charger" was a good concept after all. My original battery has made it 250k, before needing reconditioning, and if I had a 220v charger perhaps it would have been even better now.
