Engineering:Chevrolet S-10 EV

Chevrolet S-10 Electric
Chevrolet S-10 Electric
Overview
Manufacturer	General Motors
Also called	S-10 Electric S-10E S-10EV E10 E14
Production	1997-1998
Model years	1997-1998
Body and chassis
Class	Compact pick-up truck
Body style	Pick-up truck
Layout	Transverse front-engine, front-wheel drive
Platform	GMT 325
Related	GM EV1 Chevrolet S-10
Powertrain
Electric motor	85 kW (114 hp), AC induction motor
Transmission	1-speed fixed gear
Battery	16.2 kWh lead acid 29 kWh nickel-metal hydride
Electric range	16.2 kWh 33 mi (53 km)  (EPA) 43.8 mi (70.5 km) (J1634) 29 kWh 72 mi (116 km) (EPA) 95.3 mi (153.4 km) (J1634)
Plug-in charging	6.6 kW off-board Magne Charge inductive charger
Dimensions
Wheelbase	108.3 in (2,751 mm)
Length	188.9 in (4,798 mm) (1997) 190.8 in (4,846 mm) (1998)
Width	67.8 in (1,722 mm) (1997) 68.3 in (1,735 mm) (1998)
Height	62.4 in (1,585 mm)
|uk|Kerb|Curb}} weight	4,199 lb (1,905 kg) (1998) 4,230 lb (1,919 kg) (1997)

The Chevrolet S-10 Electric was an United States electric-powered vehicle built by Chevrolet. It was introduced in 1997, updated in 1998, and then discontinued. It was an OEM BEV variant of Chevrolet's S-10 pickup truck. The S-10 Electric was solely powered by electricity, and was marketed primarily to utility fleet customers.

Design

General Motors started with a regular-cab, short-box (6-foot (180 cm) bed) S-10 pickup, with a base-level trim package plus a half-tonneau cover. In place of a typical inline four cylinder or V-6 internal combustion engine, the Electric S-10 EV was equipped with an 85-kilowatt (114 hp) 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, most of the EV1 power electronics were carried over directly to the S-10 EV, which mandated that the Electric S-10 use a front-wheel-drive configuration, unlike the rear-wheel-drive setup of the standard S-10, and in the competing Ford Ranger EV.

Batteries

Similar to the Gen 1 EV1's, there were lead acid battery and nickel–metal hydride battery options. The 1997 Chevrolet S-10 EV used a lead acid battery pack. Manufactured by Delco Electronics, the 1,400 lb (635 kg) battery pack consisted of 27 cells, with one being designated as an "auxiliary" cell. These reportedly offered 16.2 kilowatt-hours for propulsion. In 1998, an Ovonic nickel–metal hydride battery (NiMH) pack was also available; these batteries were lighter (1,043 lb (473 kg)) and had a combined 29 kilowatt-hours of storage for a longer range. NiMH also has longer life but costs more than the lead acid option. The battery pack was located between the frame rails, beneath the pickup bed. On all battery types, a passive battery monitoring and management system was used; this meant that excess energy was 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 model with lead-acid battery pack, city range was 45.5 miles (73.2 km); the mixed city/highway range was 47 miles (76 km); the highway range was 60 miles (97 km) if operating constantly at 45 mph (72 km/h) or less. The acceleration time (0 to 50 mph) was listed as 13.5 seconds (at 50 percent battery charge - the published literature stated that acceleration time was "even less" when the truck had a full charge).

Like the EV1, the top speed of the S-10 EV 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 model year with the nickel–metal hydride battery, at an approximately 90-mile (140 km) range and an acceleration time of 10.9 seconds at 50% charge.

• 1997 MY GM S10 EV lead acid: 29.2 kWh/100 miles
• 1998 MY GM S10 EV lead acid: 45 kWh/100 miles (city driving), and 41 kWh/100 miles (highway driving, with maximum speed 45 mph or less).
• 1998 MY GM S10 EV NiMH: 94 kWh/100 miles (city driving), and 86 kWh/100 miles (highway driving, with maximum speed 45 mph or less).

Note: 1998 GM S10 EV NiMh numbers above are apparently wrong. This page lists the NiMH S10 with a 29-kilowatt-hour battery and range of 72 mi (116 km) (EPA) which corresponds to 40.3 kWh/100 miles (403 Wh/mile). This corresponds to the NiMH version of the vehicle having a 357-pound (162 kg) lighter battery pack than the lead-acid model.

• 1997 MY GM S10 EV lead acid: 292 Wh/mile (J1634)
• 1998 MY GM S10 EV NiMH: 276 Wh/mile (J1634)

1998 updates

While the standard 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 versus the previous year's 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 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 fuel 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, since the S-10 EV does not have the usual transmission.

Additional features

Although the S-10 EV was developed from 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, which runs on diesel fuel from a 1.7-US-gallon (6.4 L) tank. The heater will operate when ambient temperature falls below 37 °F (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 over 150 °F (66 °C), 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 crashworthiness evaluations done on stock S-10 pickups. As a result, a few Electric S-10s can still be found in use today. The fleet life of many of these ended in 2007 and 2008. The vehicles (around 440) that were not sold were eventually scrapped, similar to the fate of their EV1 siblings.

Recent uses

In 2004 GM converted an S-10 EV to rear-wheel drive, using prototype in-wheel electric motors instead of an under-hood motor.

See also

• Ford Ranger EV
• General Motors EV1, a car that shared the same technology.
• List of modern production plug-in electric vehicles

External links

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

• 1997 Chevrolet S-10 with PbA Batteries
• 1998 Chevrolet S-10 with NiMH Batteries
• Chevrolet S-10 Accelerated Reliability Report
• mailing list for Chevrolet S10 electric truck enthusiasts