Hybrid Proplusion Vehicles Using Ultracapacitors


Yesterday we strode on luminous deck tiles that used ultracapacitors to store solar-generated charge. Now we're on the road: cruising on a breakthrough design, hybrid bus that uses a bank of ultracapacitors instead of rechargeable batteries. While conventional nickel metal hydride batteries are common for hybrid-powered vehicles, Maxwell Technologies claims its BOOSTCAP ultracapacitors deliver up to 10 times the power and longevity of batteries.

Per the maker of the pictured Thundervolt system: "A similar size box of low-cost, high-power ultracapacitors will produce up to 10 times the electrical current - 1000 amperes over 100 amperes," says Maxwell Technologies executive vice president Richard Smith. "They are absolutely maintenance-free and the efficiency gain over a battery pack is about 15 to 20 percent."


Just as with the NiMH battery packs used for current hybrid propulsion systems, ultracapacitor blocks are made up of individual cells such as the BoostCap model pictured above.


Hybridize that big inernal combustion engine driven bus with them and you get this ride.

Ultracapacitors function similar to batteries, but store the charge in an electrostatic
field instead of using chemical reactions. Because of this, ultracapacitors offer advantages in maintenance, efficiency, charge rate, temperature range, cycle life and cost.

The drawback is they have a lower energy density than batteries. Excellent for the take-off, then, but less useful for extended cruising under electrical power. Buses, large vans, delivery trucks, liquid tankers, even SUV's would benefit from hybridizing with ultracapacitors if the primary use is stop and go.

And the reason we bring this up? Glad you asked. The reason is, that automotive reviewers often end their articles with a buyer beware, warning consumers that 'no one knows how long those hybrid batteries will last...so be sure to get the extended warranty' Ooooh, scary scary batteries. It's ok to order $900 pin stripes and the $1,200 "spoiler" that has absolutely no function at legal speeds though. Oh, and don't forget the $4,000 custom wheel caps that spin around like a toy on an infant's crib fence. Those are cool. 'But don't say we didn't warn you to be more practical about cars with lots of batteries'.

"Ultracapacitor" sounds so newfangled we might be able to romanticise about having some in our cars. Just imagine a line of blue LED lights spilling down on your ultracapcitor bank, blinking with the beat. For the fast takeoff artist, nothing could be finer than that blinking bank of tire squealing appeal. No more throw away lines about those scary scary batteries then.