High Voltage Safety
High Voltage Safety System
The high voltage safety system is intended to help keep vehicle occupants, technicians and emergency
responders safe from high voltage electricity.
• A high voltage fuse provides short circuit protection inside the high voltage battery.
• The high voltage safety system is insulated from the metal chassis so there is no possibility of electric
shock when touching the chassis.
• Positive and negative high voltage power cables are connected to the high voltage battery and are
controlled by normally open system main relays (SMR1 and SMR2). When the vehicle is shut off, the
relays stop electrical flow from leaving the high voltage battery.
The high voltage system may remain powered for up to 10 minutes after the vehicle is shut
The high voltage battery retains high voltage at all times.
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• A ground fault monitor continuously monitors for high voltage leakage to the metal chassis while the
vehicle is running. If a malfunction is detected, the high voltage ECU will illuminate the hybrid system
warning light in the instrument cluster.
• The high voltage battery relays (SMR1 and SMR2) will automatically open to stop the electrical flow in a
frontal collision that is sufficient enough to activate the supplemental restraint system (SRS).
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Precautions for Dismantling
Dismantling the Altima Hybrid may be performed like conventional Nissan vehicles, except as noted in these
Failure to disable the high voltage electrical system before emergency response procedures are
performed may result in serious injury or death from electrical shock.
• Failure to disable the low and high voltage electrical systems before emergency response procedures are
performed may result in serious injury or death from the unintentional deployment of the SRS.
• The Ni-MH battery electrolyte is a caustic alkaline (p H 13.5) that is damaging to human tissues. To avoid
injury by coming in contact with the electrolyte, wear proper personal protective equipment.
• Never assume that the Altima Hybrid is shut off simply because it is quiet.
• Always observe the instrument cluster for the READY operation indicator light (green) status to verify
whether the vehicle is on or shut off. The vehicle is shut off when the READY operation indicator light
(green) is off.
• The use of personal protective equipment (PPE) such as insulated rubber gloves, insulated rubber boots,
and insulated rubber mats must be used when disabling the high voltage electrical system.
The Altima Hybrid contains the same common automotive fluids used in other non-hybrid Nissan vehicles, with
the exception of the Ni-MH electrolyte used in the high voltage battery. The Ni-MH battery electrolyte is a
caustic alkaline (pH 13.5) that is damaging to human tissues. The electrolyte, however, is absorbed in the cell
plates and should not normally spill or leak out even if a battery module is cracked. Both the metal battery case
and the plastic battery modules could be breached if a catastrophic crash occurred.
• The Ni-MH battery electrolyte is a caustic alkaline (pH 13.5) that is damaging to human tissues. To
avoid injury by coming in contact with the electrolyte, wear proper personal protective equipment.
A diluted boric acid solution or vinegar can be used to neutralize a Ni-MH battery electrolyte spill, similar to the
use of baking soda to neutralize a lead-acid battery electrolyte spill.
Electrolyte leakage from the high voltage battery is unlikely due to the battery construction and the amount of
available electrolyte contained within the Ni-MH modules. Any spillage would not warrant a declaration as a
hazardous material incident. The technician should follow the recommendations as outlined in this dismantling
In an emergency, Nissan Material Safety Data Sheets (MSDS) are available by contacting:
United States: CHEMTREC at 1-800-424-9300
Canada: CANUTEC at *666 or 1-613-996-6666 (collect)
• Handle Ni-MH electrolyte spills using the following personal protective equipment:
¾Splash shield or safety goggles (fold down helmet shields are not acceptable for acid or alkaline
¾ Insulated rubber gloves
¾ Acid-resistant apron
¾ Insulated rubber boots
¾ Insulated rubber mats (for connect/disconnect of high voltage battery)
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