by Mark Smolinski (flmark)

Several weeks ago, I started a thread about my two Volts I titled A Tale of Two Batteries .

It was a story of frustration about an under-performing, unloved white Volt versus a hot red one that seemed to leave its sibling by the roadside. I am happy to report that my conclusion is that you can drive an unloved Volt back to health. While some of my results end up being anecdotal, I am confident that I started with anemia and ended up with vigor.

I am not the commuter; my wife is. Her drive is 20 miles round trip, four days per week. The roads she drives on vary between neighborhood streets at 30 mph and urban corridors where the speed limits are 45 mph. There are a few stop signs and about a dozen traffic lights along the way. And as part of the comparison, she did some 70 mph Interstate miles to see how that affected things. Since the engineers at GM seemed to be looking for answers as much as the folks here in the forum, we did our best to ascertain how one compared to the other. The problem between the two Volts stems from their history before we got them, as well as their usage (or lack of) afterward.


 

We owned a 2008 Prius and it was that car that started this process. The mileage was great. I loved cruising around at low speeds on electricity - but that made me want more. I started to read about people who were converting their Priuses into plug ins. Investigation into this concept led me to the Volt, and then to this forum, long before the car went into production. I waited and planned and we ordered a fresh, off the line 2012 red Volt that was delivered to us in December 2011. My wife fell in love with the Volt before we even owned it, as a test drive in October 2011 made her feel like it wrapped around her like a glove. The only car she had ever truly loved was her 2001 Oldsmobile Aurora, which I cajoled her into giving up for the Prius. With the Volt, she was back to enjoying the driving experience that her Aurora had given her - and she could no longer hold that Prius over my head. There was much rejoicing.

After we owned the Volt for a couple months, analysis of plug in vehicle announcements and our current inventory made us decide to ditch one of our hybrid SUVs and acquire a second Volt. So the fun began. Our dealer, Stingray Chevrolet, found us a good deal on a Volt that had sat on a dealer’s lot in Texas for a number of months. We drove it home in March of 2012, but its VIN showed it to predate our red one. It was identical in absolutely every way, except its exterior color, which was white. Even its interior
scheme was the same. Note that when inside the Volt, the only way you can see its exterior color is to look at the side mirrors for a small glimpse. No matter, my wife knew her red one was faster.

In any case, the red one got driven 20 miles daily, and plugged in each evening. The white one got used occasionally. Since the red one was our first choice, it got driven to our daughter’s residence 100 miles away, while the white one sat in the garage. Our dual residence living situation, with a NY home, meant that the red one got even more driving up there in NY, while the white one got used when my wife would return to Florida (to generate some income during our seasonal situation). The red one became my hunting vehicle, getting full discharges each time I took it out. It got driven on a 3,000 mile round trip between the two homes. By its first anniversary it had 14,000 miles on it, while the white one had 3,000.

Thanks to the phone app, and my ADHD, I noted the white Volt’s performance from afar. My first alarm came when my wife drove it to the airport in Fort Myers and got less than 30 miles on a charge. We blamed her speed. However, her commuting left her feeling that the white one just wasn’t cutting it. She thought it was her driving style, or air conditioning, or summer heat, or whatever. She blamed herself- not the car. Spending the summer with the red one up in NY, I remained aloof and was shocked upon my return in December. My mileage estimations kept coming up lower. I couldn’t get even 10 kwh of production from it, whereas the red Volt ALWAYS produced over 10 kwh. I struggled just to get to 40 miles on a charge (and never making it), whereas the red one ALWAYS achieved over 40 miles. The straw that broke the camel’s back came when I journeyed to my daughter’s place in Plant City (the home of Stingray Chevrolet, where both Volts were purchased). I drive a straight route, on back country roads. Traffic is never an issue. I had noted that with the cruise control set to 62 mph, the red Volt would get me 40 miles to a charge. At 52 mph, I would get 45 miles to a charge. So I drove the white one at 52 mph. Both on the way up, and back, I got 37 miles to a charge- a 20 percent shortcoming. Temperatures were moderate (this is Florida, where the average high and record high can be just a few degrees apart). Once the gas engine kicked in, both cars were getting me about 40 mpg. It wasn’t the engine, the alignment or the driver; it had to be the battery.

While I have referred directly to the (lack of) mileage in my discussion here, my first conclusion was that the white Volt had sat idle and unloved, baking in the Texas heat. I envisioned all manner of crusty, nasty things building up inside those cells. I took it to Stingray, expecting that there would be some magic diagnostic that would tell me my battery needed replacement. The GM engineers told Stingray personnel to start driving it to battery exhaustion. Justin, the Service Manager, took it home at night. He has his own Volt, which he apparently drives much faster than mine. He drove it as his own and noted underperformance. He altered routes and noted underperformance. Nothing earth shattering, but not meeting up to what he was used to. I kept watching the mobile app after each of his drives. Then he had another service person drive it sloooowllllyyyy around country back roads, and that person did the same with another Volt. The white Volt was coming up short, but not by much. But my mobile app told me the white Volt was doing better after each drive. Not surprisingly, when I took that same trip back home, that had previously given me 37 miles, I got 40 miles. Better, but not up to what the red one could do.


 


I was tasked by GM engineers to drive both red and white Volts to battery exhaustion before recharging, comparing the two vehicles. I came up with the best scenario I could- to have my wife drive two round trips (41 miles) to work and I would finish up until gas started burning. The results below show readings after those two round trips, and then what was displayed when the ICE kicked in. My wife valiantly avoided using anything but bare minimum fan for climate control.

1/15 White 41 miles traveled, 11 miles left estimated, 22 percent charge
remaining, 8.2 kwh used
1/16 White 49.6 miles at ICE start, 10.3 kwh used
1/17 Red 41 miles traveled, 14 miles left estimated, 26 percent charge remaining,
7.8 kwh used
1/18 Red 52.4 miles at ICE start, 10.4 kwh used
1/24 White 41 miles traveled, 4 miles left estimated, 7 percent charge remaining
1/24 White 44.2 miles at ICE start, 9.8 kwh used
1/29 White 41 miles traveled, 9 miles left estimated, 19 percent charge remaining
2/4 White 48.4 miles at ICE start, 10.2 kwh used
2/5 Red 42 miles traveled, 6 miles left estimated, 13 percent charge remaining,
8.8 kwh used
2/6 Red 49.2 miles at ICE start, 10.1 kwh used
2/7 White 43 miles traveled, 6 miles left estimated, 12 percent charge remaining,
9.0 kwh used
2/10 White 48.8 miles at ICE start, 10.3 kwh used
For the last two weeks of comparison, the route was altered to include 70
mph Interstate driving for several miles on the return home leg of the
commute, on each day (cruise control was used). This resulted in no
electric miles left after the two round trips.
2/12 Red 46.5 miles at ICE start, 10.3 kwh used
2/14 White 41 miles at ICE start, 10.3 kwh used
2/19 Red 38.7 miles at ICE start, 10.0 kwh used
2/21 White 46.6 miles at ICE start, 10.5 kwh used

Note that the Interstate driving comparisons involved some chilly temperatures (for FL anyway- in the 40s); since both vehicles managed to achieve two full round trips without the ICE kicking in (2/12, 2/21 had no bars left and either 0 or 1 miles estimated), I’d say we achieved comparable results.

My conclusions:

While I have to incorporate some anecdotal results before I had side by side
comparison from these numbers, I would say:

1) Not using your Volt often enough and/or fully exhausting its battery seems to yield a Volt battery that does not live up to full expectations.
2) You can restore your Volt’s battery performance by returning it to a pattern of frequent usage with full discharge/recharge cycles.


 

The data above seems to paint a picture of the red Volt slightly edging its white sibling. The advantage finally becomes null with the last highway trip. There are more exhaustive studies possible, but when you continue to drive vehicles in identical fashion, it makes things like shopping trips after work impossible. After several weeks of such efforts, my wife, as you might suspect, had had enough. I had purposefully alternated vehicle operations to try and average out ambient temperature variations, but I guess I was surprised that temperature effects were more noticeable than anticipated. I was expecting our moderate Florida temperatures to show 70s and 80s in lock step, but that was not the case. The Volts did better when the afternoon temperatures were in the 80s. As my wife was avoiding climate control, the Volts showed their comfort zone to be a bit warmer than ours.

I suspect that many early Volt adopters are using the car to its fullest extent and probably not experiencing what we did with our white Volt. Regardless, I would say that if your Volt usage results in only partial discharges, you should occasionally drive until the ICE kicks in. As I know GM engineers were initially involved in evaluating the white Volt, I am hoping they will examine this issue further and give us more guidance on how often we should strive for full discharges under both intermittent and completely active conditions. I am happy to see my white Volt back up to where I think it should have been all along and it is nice to know that the best medicine for an under-performing Volt battery is to get it back out on the road and use it to its fullest extent.