If the
GM Experience VIN checker doesn't explain when the battery was replaced, (the Bolt Battery Limited Part Warranty in the warranty section should show a non-round number for the mileage expiration and the date should show a date after 2027) I'd call the EV Concierge (1-833-EVCHEVY) and provide the VIN. You can also look at the sticker on the bottom of the pack. (Lay down next to the driver's door with your head just behind the seam at the back of the door.) A capacity > 60kWh suggests it's been replaced.
These will let you know when the battery was replaced and with what, but it doesn't say anything about the battery's degradation/wear-and-tear.
The dealership can do a diagnostic to check that (and
in order to get the used clean vehicle upfront tax credit, they need to provide you with a time-of-sale report that includes "capacity." I would argue that capacity means the amount of energy it
currently hold - not the
designed capacity.)
You can also buy
a OBD-ii reader for less than $30 USD and the
Torque app for your smartphone. Then download
the Bolt PIDs on your smartphone and add them to Torque. (This step is easier now than the steps on that page suggest. It let me choose the CSV from the downloads folder.) Add a widget to one of the dashboards for "!Battery - Pack - Capacity kWh estimated...". Finally, plug the device into the OBD-ii port below the steering wheel, turn on your phone's Bluetooth (and connect to the reader), and open your Torque dashboard. The car and Torque will display what
it thinks the estimated capacity is.
If both of these feel too invasive or confrontational for you to insist of the sales-person, you can do an in-your-head estimate if you can see 2 screens in the car. The first is the
driver information console screen behind the steering wheel
with the range estimation showing. This screen shows that estimation and the current charge but only shows the charge to you in 5% bar chunks. If you see this screen with the car freshly charged, you know it's at 100% but otherwise, you only know it's somewhere in that 5% range. (These bars apparently round
up BTW.)
The second screen IMO is the
Efficiency History on the center infotainment console. (If you see the
Energy Detail: Since Last Full Charge screen, that's fine too, just divide the miles number by the energy used number.) Heck, seeing the
trip info screen on the DIC is fine too, if the trip mileage is long enough.
The mile estimation is based on recent driving efficiency but people
still disagree re: what the Bolt considers "recent" for the estimation. But it can show you the range estimation because it knows it's own current charge and your recent efficiency. (If you know you drive @ 30mpg and you've got 2 gallons of gas, your range estimation is 60miles.) So "solve for X" with the 2 pieces of data you
have and you'll find the 3rd you
don't have. (Divide the miles of estimated range by the efficiency and you'll get the amount of fuel you have. If that fuel is completely, 100%, "filling the tank," then that is your fuel capacity.)
If you see the driver's screen when the car is fully charged, that's best for your capacity estimation. If you see the efficiency history and all the bars are at the same level and that level corresponds to the trip average that's even better for an accurate capacity estimation! If the range estimation is 185 miles and all the efficiency numbers say 3.2kWh, then your usable capacity is 57.8kWh. If you buy the car and drive better than all the people who took aggressive test drives, wanting to see "if this is as punchy as people say from a green light," and you improve the driving efficiency to 4kWh/mi, then the Guess-O-Meter would tell you 231 miles at 100% charge! A family member's used Bolt left the lot with a recent efficiency around 2.8kWh for perspective. If your prospective car had
that recent efficiency and 185 mile range, then it means it has a pristine battery! (I've also noticed that test drivers like to test and dealerships like to take pictures of the car with all the climate controls on. I just went on AutoTrader and picked a random Bolt listing: no wonder it's efficiency here is 2.3mi/kWh.)
If you see the efficiency numbers but not a fully charged battery, then just divide by your current charge percentage and then multiply by 100. Our Bolt on the drive below is somewhere between 15% and 19% depleted. If the 4kWh efficiency shown is close to what the car uses for its range, then the 2-month-old battery has between 61kWh and 64kWh usable capacity. (64kWh is what's on its sticker.)
(
All of these are going to be estimations BTW, (even the OBD-ii method) because of the way battery voltages and environmental factors affect "real world capacity.")
But if you've seen the screen with 185 miles @ 100% charge, I think you need to see the
recent efficiency.
Imagine you were buying a gas car from someone and asked about the gas tank and they said "I dunno.
I can only drive it 185 miles before I
have to fill it back up." BUT what they don't tell you is that he hits the gas and brake hard, never warms it up, idles at every railroad crossing, leaves the A/C or heat on full blast, has snow tires on all-year, and has a wife that loves how it squeals its tires all the time. It doesn't mean that the tank can only hold 6 gallons, it means it's twice that size but he drives like a maniac and gets 15mpg.
Beyond that, I'd run the VIN through some
history report. You say it's in great condition. If you're buying it used from a Chevrolet dealership and it's certified, I'd worry less about the car coming with surprises like brakes needing immediately replaced or shocks that are shot or whatnot. If you're buying it certified used and it hasn't been in an accident,
and if the (estimated) usable capacity on a 2 year old battery is above 58kWh,
I'd say it's a good deal.
Final caveat: even though we've been EV owners for 8 years, we've had our Bolt less than a month and our previous car was a 30kWh car whose battery
did degrade to the point it had less than 15kWh usable.
Offers you a grain of salt.
