My bars are always pink every morning...help

What is it showing when you park it at night.

 

The common reason has to do with the final miles into your garage. What sort of drive do you have for the final miles, and what is the SOC when you park it?

Tom

 

Either you are parking it at night with only 2 or 3 bars, or you are parking it fully charged and it is losing its charge though the night. Once we know the batteries state when you park it, further diagnosis can be done.

 

As long as you power down your Prius, nothing can drain the HV battery during the night. I am going to assume that you did power down since this has happened more than once, although you wouldn't be the first to leave a Prius running all night.

When powered off, a relay disconnects the HV battery from the outside world - no charge goes in, and no charge gets out. It is completely isolated. Because of this we can eliminate key fobs, lights, and other such items from consideration.

That leaves two options: 1) Your HV battery is self discharging, or 2) The battery is not losing charge, but the SOC display changes overnight.

It's not unusual to have the SOC display read differently in the morning. It's just an estimate based on a number of factors, one of which is temperature.

Less likely is a battery problem causing fast self discharge. It can happen, but it isn't common. If this is the case you will start to notice other unusual battery behavior, and eventually the system will log a trouble code and cause one of the idiot lights to come on.

Most likely it is just normal variation, which is now manifesting due to environmental conditions. I wouldn't worry at this point.

As a final note, from your description I assume the Prius is powering up with a low SOC. Please let us know if that is not the case. Sometimes a Prius will start with the SOC in the blue, and then quickly drop to pink. This is a different, so let us know.

Tom

 

If possible, show us a picture of the SOC right before nighttime shutdown and then one of the SOC first thing in the morning.

 

(you don't drive in reverse before you park it do you?)

Well the SOC will change based on hot batteries when you finish driving and then in the morning they are colder. Try leaving the A/C on the last few miles coming home and not letting it got into golf cart more (ie. press gas harder for a split second to make ICE engine come on) and see if that changes things in the morning. ie. you are losing a little bit of mpg but leaving the traction battery with a better charge.

It may also be the hill before you park, maybe as an experiment leave the car in ready in the driveway for 5 mins to see if the SOC updates before you shut it off, or maybe check the SOC 3 hrs, 6 hrs, etc after you park it and see if it changes. Maybe it isn't in the morning, but more like an hour after you park it that it goes to 3 bars.

But it is possible you have a few bad cells that are self discharging overnight and since they are bad, they charge up to full very quickly and the SOC goes back to normal after driving a few minutes. What it means if this is the case is that, those bad cell(s) are over charging when in use and generating extra heat on surrounding cells when you drive.

Might be worth looking at what a scanner says all the cell voltages are. I do not know if you would want to pay a stealership for their time to print it out though.