hybrid/traction battery loss when car is off?

Hello all,

I've had my 2015 Prius Two for almost 6 weeks now, and so far am loving it. However, I noticed something strange today. I'm pretty sure that when I parked at work this morning, the hybrid battery was nearly full (two bars shy of full, I think). When I came back to leave work (~6 hours later) and started the car, the hybrid battery was down to only two bars (as in two bars above empty mark).

I've noticed before that if the car is in ready mode, the hybrid battery will drain, but the car was off. I know it was off because I remember seeing the summary screen come on with the details from my drive to work. The hybrid battery charged just fine on the drive home, and I'll check it again in the morning.

Is this normal? It has been pretty cold for Southern California, and we received a ton of (greatly needed) rain today. Other than that, I can't think of anything that's been different.

 

Thank you all for your replies!

I'm going to start keeping a log to see what the difference usually is, and whether or not it gets worse over time. It's certainly possible that the decrease wasn't four bars but actually less. By documenting it, I won't have to rely on my (at times faulty) memory. I'll post back when I have some actual data.

 

Ok, I've been keeping my log for over a week now. Every time I turn the car off and know that it will be sitting for at least a few hours (at work or overnight), I record the date, time, outside temperature and reading of the traction battery gauge. For almost all readings so far, the number of bars on the battery gauge has not changed between power off and power on. There was only 1 instance when I powered the car back on, after it sat for 5 hours, and the reading started at 5 bars and dropped to 4 bars within a few seconds of the car powering on. I am not concerned about that as the state of the battery was likely between 5 and 4 bars when I powered off, and due to the comments above about how the gauge is just an approximation anyway.

So, good news so far (good news for the car, perhaps bad news about my memory). I will continue to log and update, in case dropping more than 2 bars is a periodic problem.

 

Another update: so far it's been the same as when I updated on January 17th. This time there were 2 instances when the traction battery gauge dropped 1 bar a few seconds after turning on, but nothing greater than that. Still looks like my memory must have been faulty when I thought I there was a 4 bar drop, but I will continue to log anyway. I'm a research scientist and I like keep logs/spreadsheets anyway.