one of the worst decisions the MBTA has ever made. battery buses are inferior to trolleybuses in pretty much every scenario, but especially winter. the battery buses they're replacing the trolleybuses with have diesel heaters to keep the batteries warm.
I'm curious how they perform in cold conditions. Where I grew up, a solid 50% of the school year was at or below freezing regularly. We really worked those bus heaters -- you know the type, under a few seats scattered around the bus. Curiously, it doesn't seem that buses use heat from the engine, like most ICE vehicles, for heat. Instead, I'm pretty sure they were just using power from the motor for electric heating elements with fans. Given that an electric bus could easily fit an enormous battery slab under the seating, I wonder if electric buses could be even better than ICE buses in cold conditions -- barring the obvious issues with battery efficiency in cold.
> climate; not only do batteries perform worse in cold weather, but heating and cooling makes up a significant amount of energy draw. In an ICE bus usually the ICE itself generates waste heat.
New Flyer, a major bus maker, is based out of Winnipeg, Canada, and is developing e-buses:
LFP batteries don't handle below-freezing temperatures very well, but that could be mitigated by using insulation and water cooling/heating depending on the time of year. Also maybe hooking them up to a pre-heater system that gets the batteries up to temperature before their route begins. (Sort of like those oil pan heaters they use in really cold climates.)
Cabin heating could be done with a heat pump for more efficiency, I suppose. Heating could consume quite a bit of power, but I suppose compared to the energy required to move a school bus around it's probably fairly minor.
The temperature does not affect to charge stored in the batteries, right? However, you have to use the battery to heat itself as well as heat the bus (unless you got diesel heater or something for the cabin).
Lithium batteries do have less usable capacity in extremely cold weather, but the real killer is heating. ICE cars have abundant waste heat to warm the cabin, but an EV has to use battery power. For a short journey on a very cold day, it's possible to use more energy for heating than propulsion. EVs are increasingly equipped with heat pumps, but you're still unavoidably going to see a reduction in range as soon as you turn on the climate control.
> He saw first hand that these trucks have far less payload capacity and range, plus the batteries lose > 40% of their range in cold weather [2].
Why not use a auxiliary battery heating system that uses some kind of fuel (i.e. biofuel) for this scenario? The amount of fuel needed to heat a battery to its optimal operating temperature during cold weather is probably orders of magnitude less than the amount of fuel needed to propel a truck, so the carbon emissions would be minimal. The same system could also be used for driver cabin heat.
They probably meant they are awful in cold weather because the cabin heater uses up 20% to 33% of the battery capacity. Newer EVs have swapped out resistive heaters for heat pumps, which helps a lot.
Oslo can't have been surprised by the existence of cold weather. Did they not contemplate any countermeasures, like heaters at the charging location or better insulating the batteries so the heat from discharging them and then recharging through regenerative braking keeps them warmer?
People have this extreme sceptisism towards electric vehicles for some reason. They have been out for many years now and have performed just fine in cold weather. Yes, they have a reduced range, that can be solved with a larger battery. I could also imagine design where a small gas/diesel engine provides heat for the batteries and interior cabin of the vehicle, leaving the batteries to power the drivetrain entirely.
Here in Kyiv (Ukraine) used Nissan Leafs from the US are popular as taxis. But what to do when it gets cold in the winter? Batteries on this car were already small when they were new, and by now they are in somewhat degraded state because Leaf's thermal management is not nearly as good as Tesla's. Heating eats that battery very quickly. So, the solution is to put a small gasoline or diesel fuel heater, and use the electric battery for everything except heating.
I can sympathize with that, but if the choice is between, say, using 1% of the battery capacity to heat the cell versus losing 25% of the capacity because they just don't work efficiently in the cold, going with the 1st option seems like the right move.
Although maybe that's not right... if a large amount of energy is "lost" when the battery is too cold, that energy has to go somewhere. If it ends up as heat anyways, maybe it's really functionally equivalent to having a heating element in the cell. In which case the solution is probably just to insulate the batteries better.
Sorry to be the bearer of bad news, but that's mostly because it's a Chevy, not because managing lithium batteries in cold weather is an unsolved problem:
If you are in a climate where freezing weather is common, you might want to swap it for a different brand. There are comparably priced options that work well in the cold (just look at the chart in the article).
No, it’s because they tend to pull energy from the charger to warm the battery. They’re also often parked indoors. And if you buy one in a cold climate, you’ll often be getting a winter package which includes a heat pump, reducing energy needed for heating the cabin and the battery by a factor of 2 to 3.
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