Chevrolet S-10 EV

Chevrolet S-10 Electric
File:S10electric.jpg
Manufacturer	General Motors
Also called	S-10 Electric, S-10E, S-10EV, E10, and E14
Production	1997–1998
Layout	Front-engine, front-wheel drive
Engine(s)	85 kW AC
Transmission(s)	none, direct drive
Related	GM EV1, Chevy S-10, Solectria S-10, Ford Ranger EV
Manuals	Service Manual

The Chevrolet S-10 Electric was introduced in 1997 by General Motors, updated in 1998, and then discontinued. It was an OEM BEV variant of Chevrolet's S-10 pickup truck which ran solely upon electricity, and was marketed primarily to utility fleet customers.

Design

General Motors started with a regular cab, short-box (6' bed) S-10 pickup, with a base level trim package, added a half tonneau cover. In place of a typical inline four cylinder or V-6 engine, the Electric S-10 EV was equipped with an 85 kW (114 horsepower) three-phase, liquid cooled AC induction motor, based on GM's EV1 electric coupe. The EV1 had a 100 kW motor, GM reduced the S-10EV's motor because of the additional weight and drag of the truck so as not to overstress the batteries.

Other than the reduced motor size, the majority of power electronics were carried over directly from the EV1, which mandated that the Electric S-10 use a front-wheel-drive configuration, unlike the rear-wheel-drive setup found in stock S-10's and in the competing Ford Ranger EV.

Batteries

Similar to the Gen 1 EV1's setup, the 1997 Electric S10 stored and sourced its power from a lead acid battery pack. Manufactured by Delco Electronics, the 1,400 lb (635 kg) pack consisted of 27 batteries, with one being designated as an "auxiliary" cell. These reportedly offered 16.2 kilowatt-hours for propulsion, and offered a varying driving range. In 1998, Ovonic NiMH batteries were also available. These batteries were lighter at 1,043 lb (473 kg) and had 29 kilowatt-hours of storage for a longer range. NiMH also has longer life but cost more than the lead acid option. The battery pack was located between the frame rails, beneath the pickup bed. On all battery types, an passive battery monitoring and management system is used. This means that excess energy is wasted from cells with a higher charge, while the remainder of the cells reach the same state of charge.

Charging

The S-10 EV charges using the Magne Charger, produced by the General Motors subsidiary Delco Electronics. The inductive charging paddle is the model J1773 or the 'large' paddle. The small paddle can also be used with an adapter to properly seat it. The standard charger is a 220 V 30 A (6.6 kW), there is also a 110 V 15 A 'convenience' charger, and a high power fast charge version.

The vehicle's charging port is accessed by flipping the front license plate frame downwards. The system is designed to be safe even when used in the rain.

Efficiency

Depending on the load and driving conditions the range can vary greatly.

For the 1997 PbA, a city range of 45.5 miles (73.2 km), a mixed (city/highway) range of 47 miles (76 km), and a highway range of 60 miles (97 km) if operating constantly at 45 mph (72 km/h) or less.

GM estimated 0-50 mph times of 13.5 seconds at 50% charge; "even less" when the truck had a full charge. Like the EV1, the top speed of the truck was governed, albeit to 70 mph (113 km/h), 10 mph (16 km/h) less than its coupe sibling.

The performance is much better for the 1998 NiMH, at ~90 miles range and a 0-50 mph of 10.9 seconds at 50% charge.

1998 GM S10 EV lead: 45 kW·h/100 mi city, 41 kW·h/100 mi highway
1998 GM S10 EV NiMh: 94 kW·h/100 mi city, 86 kW·h/100 mi highway

(Source: Model Year 1999 EPA Fuel Economy Guide)

1998 updates

While the internal combustion S-10 moved to a redesigned front fascia in 1998, the S-10 Electric kept the same front fascia as the '94-'97, with the exception of composite headlamps in 1998 verses the previous years sealed beam headlamps. The interior was also updated in 1998 along with internal combustion models, adding a passenger side airbag. Aside from this header panel, a unique lower bumper valance, and a stylized 'Electric' decal on the bottom of the doors, there is very little difference externally between the appearance of an Electric and a stock S-10. Any changes, however minimal, were reported to have had a positive influence on reducing the truck's aerodynamic resistance. These changes included a closed grille and a front air skirt, belly pans beneath the front suspension, a seal between the cab and the pickup bed, and a half-length tonneau cover over the rear of the pickup bed.

Instruments

Internally, the instrument cluster was exclusive to the Electric S-10, and featured only four gauges - a speedometer, a large "charge" gauge which reads from 'E' to 'F' like a gas gauge, a voltmeter ranging from 220 to 440 volts, and a "power use" meter, which acts as an ammeter of sorts showing discharge during acceleration and charge during regenerative braking. The LCD display for the shifter was shortened to display only park, neutral, reverse, and drive, due to the absent unnecessary transmission.

Additional features

Despite the truck being based on a "base" trim package, the Electric S-10 still came standard with dual airbags in 1998, a heat-pump for both air conditioning and heating, power four-wheel ABS brakes, regenerative braking, power steering, AM/FM radio, and daytime running lamps, among other items. For colder climates, a fuel-fired heater was standard, it runs on diesel fuel from small 1.7 gallon (6.4 L) tank at temperatures below 37 degrees Fahrenheit (3 °C).

Because battery performance varies greatly with temperature, the heat-pump supplies cooling to the batteries during charging when necessary. Passive air recirculation is used during the driving cycle to equalize variations in battery temperature. The heat-pump can be activated during the driving cycle under extreme battery over temperature conditions >150F, typically as a result of extreme battery discharge.

Sales

Unlike the EV1, of the 492 S-10EVs assembled about 60 were sold to fleet customers, rather than just leased through restrictive programs, mostly due to the prior Department of Transportation crash-worthiness evaluations done on stock S-10 pickups. As a result, a few Electric S-10's can still be found in use today. The fleet life of many of these are ending in 2007 and 2008 and they can be acquired in government and business auctions. Those 440-some that were not sold were collected, dismembered and crushed just like their EV1 siblings.

Recent uses

In 2004, GM converted a leftover S-10 Electric to rear-wheel drive, and harnessed its power through prototype in-wheel electric motors, as pictured.

External links

Idaho National Laboratory operated for the U.S. Department of Energy's Office of Nuclear Energy, Science and Technology:

EV Bones specializes in S10EV sales and service.
mailing list for Chevrolet S10 electric truck enthusiasts

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