I'm parking my car for two weeks, so pulled the ECS-B2 fuse under the hood (controls the key sensors) to see if that will prevent the 12V from draining. Although it's hard to prove a negative.
My 2006 will easily go two weeks without pulling fuses or disabling the SKS, and this is with the original 12V battery. Tom
sipnfuel, I think Tom was saying his car is OK for two weeks, not that the battery "goes" after two weeks. I've left mine for two weeks or more several times with no issues; the smart key system on the Gen 3 goes to lower power mode as the car sits idle for several days - for example, it disables it on all doors except the driver's door. You can tell when this happens - normally, just touching the inside of the handle will unlock it. But after a few days, you'll actually have to pull on the handle to get it to unlock.
I've had it die over two weeks before. There had been snow piling up, so I think the handle thought it was being touched, which resets the 3-day (or is it 5-day?) shutoff of the SKS system. I'd also bought a solar charger, but I've misplaced it.
A healthy 12V lead acid battery, with no loads on it should hold the volatge over 12.5 for at least 4 months. If a lead acid battery slowly discharges over 2 weeks down to 12.4 or less it is suffering from an internal high resistance short or is very worn True open circuit voltage could not accurately be read unless the battery rests unloaded for 24 hours. Brand new and never used or charged, could read as high as 12.9V New and in service and after 24 hours it should read 12.6 V having 100% of original capacity. After an assured rcharge, as the battery wears and after a 24 hour rest, anything less then 12.4 should be replaced as it is worn and is now low in capacity.
Unfortunately, the current draw for a parked Prius is a lot higher than no load. The Prius does eventually shut off SKS, but there are still many residual power requirements. Tom
I think it will depend on your battery SOC when you park it. Here's the arithmetic. Prius idle drain = 0.01A plus another 0.006A when the doorlock ikon flashes, lets say 0.02A continuous. So one day drain = 24X0.02 = 0.48 ampere hours. After a week = 7X0.48 = 3.36 ampere hours. Divide 3.36 into what you think your battery ampere hour capacity is and there's your answer in weeks. Don't know for sure but going by the physical size, original Prius battery looks about 30 ampere hour if fully charged.
Perhaps the weather conditions have exploited the battery drain condition? I saw the mention of snow.
No problems with the car. I used the hard key to get in, heard the brake pump up, popped the hood. Measured the battery at the fuse box with an analog meter at 12.5V (could've been as much as a quarter volt higher or lower). Replaced the fuse, and went on my merry way. The good part of doing it this way, rather than pulling the connection at the battery, is not having to reset everything. Still, can't prove it was the SKS that did me in before, though.
Would you just happen to know what amperage draw the SKS system and the remote key fob block-unlock system have? Those I can turn off from the "vehicle" menu on my 2012. Would you happen to know the current draws of the other systems that stay active when the car is turned off? Thanks in advance, mate.
