[Joelaw1]

2014 VOLT. 56000 miles. About 50% electric/ 50% gas miles.
Today, my car went to the dealer for the second time, same symptoms.
For the first 50000miles or so, my car charged from 38-43 miles, whether on 120 or 240 volt charger.
In December, I parked the car for three weeks at San Francisco Airport.
I drove home (4 hours) and got unusually low miles.
Since then, the car won't charge above 33 miles, and it's usually closer to 29-30.
Dealer has reset the software and had me drive a few thousand miles.
Returned today and dealer found no codes.
I read and implemented GM recs (Document ID: 4726641) long ago.
Now, everyone is stumped and I'm getting 20-25% fewer miles on the battery.....

 

[saghost]

GM "miles" in the Volt/Spark/Bolt are based on the car's recent experience and outside temperature, rather than just the amount of charge in the battery.

Before assuming the hardware is broken, I'd start with the operating environment. Are all the settings the same as the were. In particular, Comfort climate control mode and auto-defog can chew through a bunch of extra energy.

With 50k, you are presumably familiar with the drop in range in colder weather, and are driving the car the same way over the same roads as before?

A couple of Volts have had jammed rear brakes that led to lower mileage - use an infrared thermometer to check the temperature of each disc after a drive.

If you have a solid dataset of extended range gas mileage for the car, it might be worth taking an extended drive that you've done before in similar condition and seeing if the gas mileage lines up - one way to tell between a battery problem and a more general car problem.

Another would be to use an energy measurement outlet to charge the car and see how much power it takes to fill.

 

[caronjeff]

Did you recently buy new tires?

 

[DonC]

You might want to check the charged SOC on the OnStar app. Sometimes I find it charges to 94%-96% rather than 100%. Makes a difference of a few miles.

I was also going to ask about new tires ....

 

[Barry]

I would suspect that there is a mechanical problem that occurred while parked at the airport or maybe while driving to or from the airport. Something like a stuck brake caliper, as mentioned by saghost, due to the parking brake being engaged for 3 weeks without movement. Or possibly an alignment problem caused by another car striking yours in the parking lot or you hitting a road hazard.

 

[SharkVolt]

If you just bought the Volt used, you need to know that the range gets less in the winter, and it will go back up in warmer weather.

 

[llninja]

Did you recently buy new tires?

Another possibility, do you have a teenager with a recently acquired license? Or a significant other who borrows the car when you're not looking?