Download Hybrid Collision Repair: Safety First

Hybrid Collision Repair: Safety First
Posted 6/15/2006
By Andrea Betts Menendez
Hybrids are flying off the lots. The more hybrids on the road, the sooner one
will show up at your shop. Are you up to the challenge?
Thanks to climbing gas prices, new tax deductions
and growing environmental awareness, hybrid
vehicles are flying off the lots almost as soon as they
arrive. The more hybrids on the road, the sooner one
will show up at your shop, especially since these
more expensive vehicles are less likely to be
considered totaled. Are you up to the challenge?
First Things First
"Read, read, read," advises Mike Schoonover of Schoonover Bodyworks Inc. in St.
Paul, Minn. "Read anything and everything you can to learn more about the vehicle."
Schoonover's shop has repaired more than a dozen hybrids. "All of our techs
attended the I-CAR hybrid class, which was very informative," he said. "We
purchased the necessary tools and safety equipment and bought a toolbox that is
strictly used for hybrid repairs." The toolbox contained electrical lineman's gloves,
which Schoonover identified as the most important item (see "Hybrid Safety Tips").
Education is essential to safely and successfully repairing a hybrid car. Technicians
must be able to identify a hybrid's key electrical components, which generally include
a high-voltage, nickel metal hydride (NiMH) battery pack; a 12-volt auxiliary battery;
high-voltage cables wrapped in orange insulation; a power control device or inverter
and a service disconnect. Always consult the manufacturer's service manual when
repairing a hybrid vehicle, as each model is slightly different.
A proper repair also requires an accurate assessment of the damage. "We
recommend checking the hybrid system for proper operation before repairing the
body damage if at all possible," said Craig Totten, instructional designer for the
Inter-Industry Conference on Auto Collision Repair (I-CAR). Severe damage to the
expensive hybrid system could lead the insurance company to deem the car totaled.
Disabling the High-Voltage System
All authorities agree: the most important thing to
know is how to disable the high-voltage (HV) system.
"This must be done before doing any work to the
vehicles," stressed Totten. "It's like taking the bullet
out of the gun."
Basic steps for disabling the HV system include the
following:




It is important to keep the key off, out of the
First, make sure the ignition has been turned
ignition switvh, and in a highly visible location
off and the key has been removed. This is
such as on top of the dash board when a hybrid is
in the shop.
important because a full hybrid runs on its
silent electric motor when stopped and may appear to be turned off. Backup
options include removing the IGCT Relay or the HV fuse under the hood.
Disconnect the 12-volt battery.
Wear 1000-volt Class 0-rated insulated rubber gloves and follow any special
instructions provided in the service manual for disabling the high voltage
system. Procedures may vary between vehicles and may include removing a
service plug or removing a locking tab and flipping a switch.
Check orange cables for any current using a CAT III certified digital volt ohm
meter (DVOM).
Once the HV power has been isolated to the battery pack, techs can either avoid the
battery during repairs or remove it after disconnecting the HV cables. When working
on his first hybrid, Schoonover took no chances. "We had a technician from the
Toyota dealership we work with come over to assist us with pulling the battery from
the vehicle, which was a Prius."
Special Considerations
Once the HV system has been disabled and/or
removed, repairing a hybrid is, for the most part,
business as usual. A few special considerations must
be given, however.
First, take care not to subject hybrids to high
temperatures. "Turn down the heat of your spray
booth, as NiMH batteries don't like heat," advised
Craig Van Batenburg, AAM, owner of the Automotive
Career Development Center. While technically, normal bake temperatures can be
used with proper monitoring, Van Batenburg recommends keeping the temperature
well under 140 degrees Fahrenheit. He also suggests painting all hybrids at the end
of the day and allowing them to dry overnight.
Orange cables indicate high voltage. On this
2004 Toyota Prius, the protective sheath is
shown.
Totten noted that techs should use common sense when performing tasks like
welding. "Don't apply heat right next to the battery pack without removing it first,"
he said.
Low temperatures can also be problematic.
Schoonover Bodyworks found this out during their
first hybrid repair. "One of the things we learned was
that the Prius cannot sit for two weeks or more in
below freezing temperatures without the 12-volt
battery going dead," said Schoonover.
Hybrids can be jump-started according to
manufacturer instructions. A dead high-voltage
battery, however, is another story entirely.
A technician checks for the presence of voltage at
the junction board terminals to the high-voltage
battery after disabling the high-voltage system on
a 2001 Honda Insight.
"[NiMH batteries] have a very high self-discharge
rate, as much as 30 percent per month. Meaning if they are left sitting for a period of
two to three months, they will go completely dead," Totten explained. "Running the
gasoline engine on the vehicles is typically the only way to recharge them, so it is
recommended to start a hybrid that is sitting every two to three weeks and let it run
for 20 to 30 minutes to keep the batteries charged, as long as the damage does not
make it impossible to do so."
Keeping the HV battery charged should be a top
priority, as chargers for models like the Prius are rare
and battery replacement is expensive. According to
Totten, this problem is avoided in Honda models.
"Hondas have an auxiliary 12-volt starter that can
start the gas engine when the high-voltage battery is
too low. Then the vehicle can be driven to recharge
the high-voltage battery." HV cables may need to be
A technician disables the high-volyage system in replaced in a damaged hybrid. "Because of the high
a 2004 Toyota Prius by pulling the service plug
voltage carried, any damage to the insulation of the
from the high-voltage battery. Notice he is
cables - even a pinhole - can result in a potential
wearing the high-voltage lineman's gloves while
short," said Totten. Before handling any cables, techs
performing this important function.
should test them with a DVOM to make sure no
voltage is present. Always keeping safety in mind, techs should also inspect their
work afterward. "Ensure that the cables are properly routed and in the protective
sheaths underneath the vehicle, and that all connections are torqued to specification
before enabling the high voltage system," Totten advised.
Alternative Materials
Anyone who has worked on a Honda Insight knows that it differs from other hybrids
in one important respect: its body panels are aluminum. More and more automakers
are using aluminum and other lightweight material like plastic and laminated steel to
improve fuel efficiency. While the Insight is the only aluminum-intensive hybrid
currently on the market, aluminum is showing up in hoods, decklids, suspension
parts and subframes everywhere.
Because of its unique properties, repairing this metal requires special techniques and
equipment, such as a stud welder and an aluminum MIG welder. The equipment
investment runs around $7,000 or $8,000, according to Mike West, collision
chairman for ASA-Washington and owner of Southtowne Auto Rebuild Inc. in
Tukwila, Wash. Which shops should learn to repair aluminum? Some say it's a
question of cost/benefit, but West disagrees. "Everyone should know how to repair
aluminum," he said. "Because Ford, Buick, Lincoln, Toyota, Honda all [use] some
aluminum.
Knowledge is Key
Schoonover emphasized the importance of gathering information about any hybrid
vehicle that arrives at the shop. "We download the most current hybrid information
from I-CAR and the OEM Web sites," he said. "We also utilize data from trade Web
sites and magazines.
"As you do when working with airbags, always treat these systems with the respect
they deserve," said Totten. "Once a technician understands these systems and
knows the proper procedures to follow, the fear factor associated with them goes
away."
Hybrid Safety Tips
Follow manufacturer instructions for moving a hybrid. Always tow with the drive
wheels off the ground. Pushing a hybrid can generate electricity, so using wheel
jacks is often recommended for moving the car around the shop.
 Always wear the proper safety gear, including
electrical lineman's gloves. Following
manufacturer instructions, disable the highvoltage system, test for any stray current
with a CAT III certified digital volt ohm meter
(DVOM) and avoid or remove the nickel metal
hydride (NiMH) battery pack.
 Make certain the system has been properly
These technicians have the tires on dollies to
disabled before using welding tools, which can
avoid charging up the condensers in the inverter
act as electromagnets and send power
by pushing the vehicle with the drive wheels on
the ground. This is especially important if towing
throug
the vehicle with another vehicle and a towrope.
h the
system
.
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Use extra caution if you suspect the
collision may have damaged the HV
battery pack. Wear rubber gloves and
safety goggles, as NiMH batteries
contain a potassium hydroxide (KOH),
a highly alkaline solution that damages
human tissue. Potassium hydroxide
also produces hydrogen gas, which is
A technician rolls up the rubber-insulated
lineman's gloves to ensure there are no pinholes
flammable when it contacts certain
in them before use.
metals.
Neutralize a battery leak by spraying it
with a diluted boric acid solution or vinegar. Use litmus paper to test for
alkalinity. When the red paper remains red, the solution has been neutralized.
Talk with first responders in your area to verify they are prepared to assist in
an emergency. Water can be used to extinguish a fire, even one involving the
NiMH batteries, without the risk of shock or electrocution. However, hydrogen
gas may result, as may a host of other poisonous gases in the case of a
battery fire. Make sure your fire department knows how to handle a fire
involving a hybrid.
- A.B.M.