There are two ways to make all-electric buses: with enormous batteries that yield long range or average-sized batteries that yield average range but can charge very, very fast. The former is the path that BYD has chosen, with their 324 kWh Iron-Phosphate battery achieving 155 miles of range. The latter is the direction taken by Greenville-based Proterra and their “infinite-range” electric bus capable of recharge times of less than 10 minutes.
Hybricon Bus Systems, the Swedish manufacturer of the marvelously named Arctic Whisper electric city bus, also has opted for ultra-fast recharging. Charged EVs reported that the current prototype bus uses a charging system known as Opbrid Bůsbaar (adapted from electric train systems) that dumps electricity into the 100 kWh battery at 400 V DC and a mind-blowing 625 A, for a total charging power of 250 kW. This is double the power at which Tesla’s Supercharger network operates.
The current system is capable of charging at 300 kW and yet only produces a temperature rise of about 10 degrees C at the junction between the pantograph and the overhead charging rail. Hybricon is not satisfied, however, and neither are fleet operators; the company wants to reduce the current 6-minute charge time to just 2-3 minutes by increasing the charge rate to 650 and 950 kW.
“The local bus operator only has a few minutes to charge at the ends of the route, so we developed this bus to satisfy this demand,” pointed out Hybricon CEO Jonas Hansson. He elaborated on the bus’s unique requirements for operating near the Arctic Circle, which include a robust electric heater and a unique battery design optimized for cold-weather optimization. The battery chemistry is also ideally suited for accepting high charging rates.
For urban bus operators, the shorter the charging time the better. Proterra’s current system is capable of recharging in about 8 minutes, which is sufficient for the needs of many bus routes that begin and end at a central terminal where the bus may be recharged. Shorter charge times, however, reduce the need for additional buses and allow more flexibility in route planning. As a result, fast-charge bus manufacturers are striving to lower their times into the 2-3 minute range.
Electric buses are a proven way to save fleet operators enormous amounts of money in fuel costs while eliminating tailpipe emissions. Their huge batteries and expensive charging equipment can be prohibitive up-front costs for many cities, but those able to make the investment are rewarded. Hybricon and their Arctic Whisper seek to improve the technology even further and demonstrate that recharging time doesn’t have to be an obstacle for electric vehicles.
Comments
Sweet. A recharge time of 2
Permalink
Sweet. A recharge time of 2 to 3 minutes would allow this vehicle to recharge in less time than it would take to dump 150 gallons of diesel fuel into the fuel tank. Recharging rates at this speed are needed to increase the mass acceptance of EVs.
I agree with you, Mike. A
Permalink
In reply to Sweet. A recharge time of 2 by mike w (not verified)
I agree with you, Mike. A city bus doesn't HAVE to have a lot of range per charge - if they can get 100 miles of range with a full load of passengers on a 5 minute charge, that'd be great for those places that use mass transit.
It is one thing for city
Permalink
It is one thing for city buses to recharge this fast, but it would be quite impressive if EVs were capable of the same. Tesla clearly has their sights set on similar goals: http://www.technologyreview.com/news/516876/forget-battery-swapping-tesla-aims-to-charge-electric-cars-in-five-minutes/
When I was growing up in the
Permalink
When I was growing up in the 70s (I'm 46) the cities I lived in around Boston had electric buses that had no batteries. No charge time.