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?
Unless it goes into storage with 8 bars (really full) or 0 bars (REALLY empty) this is a non-issue. the prius tries hard to keep 6 bars. maybe after six months it would be at 5 or even four, but that is absolutely not a problem. You would definitely need to disconnect the 12V, or leave a trickle charger attached.
I agree with the service manager and the above post. Disconnect the 12V battery and put it in storage with 5 or 6 bars on the traction battery and it should be fine for an indefinite period. The traction battery is completely disconnected when the car is off, discharge will be minimal.
I would be concerned for the below reason: Self-discharge NiMH cells historically had a somewhat higher self-discharge rate (equivalent to internal leakage) than NiCd cells. The self-discharge is 5–10% on the first day and stabilizes around 0.5–1% per day at [ame="http://en.wikipedia.org/wiki/Room_temperature"]room temperature[/ame].[14][15][16][17][18] This is not a problem in the short term but makes them unsuitable for many light-duty uses, such as clocks, remote controls, or safety devices, where the battery would normally be expected to last many months or years. The rate is strongly affected by the temperature at which the batteries are stored with cooler storage temperatures leading to slower discharge rate and longer battery life. The highest capacity cells on the market (>8000 mA·h) are reported to have the highest self-discharge rates. from: Nickel-metal hydride battery - Wikipedia, the free encyclopedia At least I would try to start storage with battery as full as possible. If I may ask you, why buying prius if using a car so little?
If our battery was at 8 bars (80% SOC) it has ~950 watt hours of power in it. if we lose in the worst case 1% of the charge per day it takes 69 days to reach ~480 watt hours (40%). However, comparing old information on consumer grade cells to the patented and automotive specific cells in the prius is not going to give accurate results.
Even when it's locked with everything you can control turned off, the car takes enough current to drain the 12v battery within a few months---besides the self-discharge of the battery.
