Pun intended. As others have posted not enough consideration has been made of the limitations of all batter electric vehicles. Hybrids still to be evaluated. maybe these all battery buses will need to be converted to handle trolly poles?
Minnesota Cities Went All-In for Electric Transit, But the Buses Couldn’t Handle the Cold (msn.com)
The class 1 RRs need to also consider this a big problem for road locos.
FTA:[noted, in part,] [In OP’s linked article] "…The most significant aspect of this story, however – or at least the one that makes it relevant to readers outside of Minnesota – involves the perennial unholy alliance between government and business.
In 2021, Metro Transit received a federal grant to purchase a fleet of electric buses from the California-based manufacturer Proterra. Duluth received a similar grant in 2015.
Earlier this year, Proterra filed for bankruptcy despite a public endorsement from President Joe Biden as recently as March 2022…"
NOW, there is, apparently, no service, or mantenance back-up, providedf by Proterra, the EV Bus Manufacturer?
Thanks, BS1 for the article; the last couple of days [Post Cristmas 2023].
From the article: “In subzero conditions – a staple of Minnesota winters – electric buses operate at only a fraction of their supposed 150-mile capacity.”
Gee, I guess no one saw this problem coming earlier. Maybe once they’re running again, they can have a sign on the bus door encouraging riders to bring a heavy coat.
Hardly. It’s a well-known issue, and one that people are going to have to work through. That’s a lot of the point of these little 8-bus orders supported by grant funding - work out the kinks and find something that works.
I think winter performance should be a non-issue for battery-powered freight locomotives.
The biggest reason that BEV range decreases in winter is the need to supply heat to the cabin. Electricity is needed to run a heat pump or resistive heater, and that electricity comes from the same battery pack that runs the motors. In an automobile driving around town averaging maybe 15 MPH, the energy needed to provide heat is pretty significant compared to the energy needed for propulsion. For a transit bus averaging less than 10 MPH, with a larger surface-area-to-weight ratio, the heating becomes an even bigger suck on the battery, proportionally speaking. By contrast, the energy needed to heat the cabin of a locomotive is totally insignificant compared to what is needed to pull 10,000 tons of freight. So freight locomotives should be fine.
The electrical performance of a battery is not dependent on the weather outside but on the battery temperature. It doesn’t take much energy at all to keep a battery pack within its optimal range.
Dan
Dan’s right; this should have been almost a non-issue. Ford did the original hard work many decades ago, for the sodium/sulfur battery; Tesla has made battery conditioning (both heating and cooling) a significant part of its charging and regenerative-braking algorithms. Very, very good (and low-cost) nanoilnsulation is easily available for the necessary blanketing… assuming the designers have provided active pumped heat transfer through the battery cells.
Assuming.
It’s certainly far from a showstopping problem… if steps are taken to fix the problem from first principles.
Cannot blame this problem on cold weather. Antelope Valley transit authority suspends some electric bus operation as charging issues have appeared.
Seems that battery bus technology is still going through the shakedown phase, with at least a few bugs to be worked out. While I think it is a good idea to ahve some on the road to get real world experience to find problems such as the one mentioned in the article, it’s still a bit early to mass replacements of diesel or CNG buses with electrics. A good interim step would be hybrid buses, which would reduce fuel consumption as well cleaner running engines.
Note that the Antelope Valley folks say there are no reported issues with charging the BYD buses or the paratransit vans.
To me, that points to the detail design of the MCI buses, perhaps with cooling during fast charging. For the whole fleet to be abruptly taken out of service, with the implicit further note that it will be at least weeks until anything practical can be done, for “safety” reasons would be concerning if it isn’t an excuse.
The concern I have technically is that the difference between the BYD and MCI coaches is that the latter are larger, higher-speed vehicles, very similar to what would be practically required for OTR Class 8 truck replacement in California. This problem is not some little glitch that wasn’t caught by a junior engineer during R&D testing.
I agree on MCI battery problems being more of a fundamental problem than a design oversight. With respect to fast charging, the hazards include shortening the life of the battery as well safety. There is quite a bit of research on battery technologies that permit fast charging while maintaining the high cycle life needed to make battery buses economical - many stories about silicon electrodes, but time will tell if the promise turns into reality.
One possible source of the problem with the MCI batteries is the temperature monitoring of the individual cells, as the “fuel gauge” algorithm needs precise voltage measurements along with cell temperature. Another possible cause is too much variation in cell temperature in the batteries.
Battery output is from a chemical reaction - all chemical reactions are affected by dropping temperatures - some more than others.
Had a Triumph TR-4 - at Zero and above it would start no trouble. BELOW Zero it was a no go.
Thing is that modern traction batteries have had temperature regulation for many years: they are heated to ‘optimal’ temperature before any traction current is drawn from them, and they’re supposed to be regulated via heating and cooling to the right range for their internal chemistry all the while any kind of charging is engaged in.
Theory and Reality - they rarely are the same. Does the mechanizm used to heat the battery to ‘working temperature’ use power from the battery that is below working temperature to get to working temperature, thus using a significant amount of the total battery potential in doing so?
Unless the EV in question is plugged into a charger, the battery thermal management system does indeed draw down the battery in order to warm up. A heat pump may be an energy saver here as the output temperature needed to warm the abttery is quite a bit less than for the cabin. Conversely, in very hot climaes such as Phoenix in mid-summer, the battery thermal management system uses battery power to cool the battery, though don’t recall if the cooling involves refrigeration.
For areas with cold winters, I think a hybrid EV (car, bus or MU) makes more sense than a pure EV.
As you might suspect – not all EV engineers being fools – the battery ‘heating’ is inside heavy thermal insulation, and of course is brought up to 'operating temperature’by a tap from charging current, and can be brought up during periodic recharging enroute if the carrier uses that.
Bus batteries likely have less proportional surface area to mass, and are easier to package with insulation, than (say) an automobile battery shoehorned into an irregular space between the trunk and the back seat. This is also not like cheap block or oil heaters in light diesel trucks, where careful insulation or hot prelubing aren’t enough of a ‘thing’ to justify the added cost and complexity.
Do you think Wabtec’s deciding to invest in hydrogen technology signals a reduced role for battery technology for the majority of commercial transportation equipment?
Yesterday rode two different battery-electric buses in local service in bJerusalem, the first time two in one day, The first Egged 34, the second 48A, used to nbe Egged, now Afikim. No problems that I am aware of by either operator. Appreciared the quiet and fast ecceleration.
About 65% of the non-articulated buses of the Jewish-run Jerusalem local lines are battery-electric niow. Very few articulateds and none so far in the Ara sector that I’ve ridden or seen,