Safety During Repairs

General

The battery is a high voltage, high current, lithium ion battery pack capable of delivering hazardous electrical shock if not properly handled. This section highlights proper safety and handling procedures to minimize any electrical hazard to the technician and the battery components. Because of its built-in, multiple redundant safety mechanisms, the battery does not normally present any hazard to service personnel. These procedures highlight additional safety steps to ensure that any breach or failure of internal safety mechanisms does not accidentally expose a service technician to electrical hazard.

WARNING: Ensure that there is at least one other person present in the area during repair procedures.

WARNING: Voltages of greater than 50 V applied across dry unbroken human skin are capable of producing ventricular fibrillation if they produce electric currents in body tissues. Even at currents as low as 300 to 500 mA, ventricular fibrillation may be induced. Ventricular fibrillation is uncoordinated contraction of the cardiac muscle of the ventricles in the heart resulting in serious breathing difficulties.

WARNING: Always ensure that a defibrillator and an insulated hook are available at all times when working with the battery.

WARNING: Always ensure that high voltage insulated gloves, eye protection and rubber soled shoes are used at all times when working with the battery.

WARNING: Whenever possible, perform repairs using one hand while holding the other hand behind your back. This reduces the likelihood of touching both the positive and negative contactors of the battery. In the event of electrocution, this position will also reduce the likelihood of voltage passing across the chest area resulting in heart fibrillation.

WARNING: Under normal conditions of use, the constituent battery cells are hermetically sealed. Contents of an open (broken) constituent battery cell can cause skin irritation and/or chemical burns. If materials from a ruptured or otherwise damaged cell or battery contact skin, flush immediately with water and wash affected area with soap and water. For eye contact, flush with significant amounts of water for 15 minutes and see physician at once. Avoid inhaling any vented gases. If a chemical burn occurs or if irritation persists, seek medical assistance.

WARNING: Ensure that when E-connectors and insulators are removed, a clear E-connector cover is used to cover the exposed terminals.

WARNING: Keep protective PEM positive (B+) and PEM negative (B-) cable service covers in place throughout repair procedures at all times until it is time to connect the cables to the PEM. This will help protect against accidental shorting if an attempt is made to energize the cables (by closing the contactors) before the cables are attached to the PEM. These plastic covers add an extra level of shock hazard prevention by providing an electrical insulation layer during handling of unattached cables.

WARNING: Ensure that only the approved Tesla battery tools are used to service the battery and that the insulation is in good condition. Should the insulation become damaged or worn, the tool should be removed from use around the battery.

WARNING: If for any reason you need to stop working in the middle of a procedure, cover any exposed E-connectors with clear covers and the entire enclosure with a high voltage cover.

CAUTION: Keep high voltage, insulated gloves in a protective bag when not in use to protect them from damage. If the gloves are split or cracked, voltage may pass through the material into the body.

Fire

In case of a battery fire, flood the area with water. The water may not extinguish the fire, but will cool the adjacent area and control the spread of the fire. Carbon dioxide, dry chemical and foam extinguishers are preferred for small fires, but also may not extinguish burning lithium ion batteries. Burning batteries will burn themselves out. Virtually all fires involving lithium ion batteries can be controlled with water. When water is used, however, hydrogen gas may be a by-product which can form an explosive mixture with air. LITH-X (powdered graphite) or copper powder fire extinguishers, sand, dry ground dolomite or soda ash may also be used. These materials act as smothering agents.

Damaged or opened cells or batteries can result in rapid heating (due to exothermic reaction of constituent materials) and the release of flammable vapors. Water (and other items listed above) disperses heat when applied in sufficient quantity to a fire. Extended heat exposure can lead to ignition of adjacent cells with a potential complete envelopment of the battery if not cooled.

An extinguished lithium ion battery fire can re-ignite due to the exothermic reaction of constituent materials from broken or damaged cells. To avoid this, remove sources of ignition and cool the burned mass by flooding with (or immersing in) water. Firefighters should wear self-contained breathing apparatus. Cells or batteries may flame or leak potentially hazardous organic vapors if exposed to excessive heat, fire or over voltage conditions. These vapors include hydrogen fluoride, oxides of carbon, aluminum, lithium, copper, and cobalt. Additionally, volatile phosphorus pentafluoride may form at temperatures above 230°F (110°C).

Safety When Handling

Storage and Transportation

Storage

DO NOT store batteries in a manner that allows terminals to short circuit. DO NOT place near heating equipment, nor expose to direct sunlight for long periods. Elevated temperatures can result in reduced battery service life. The desired longer-term storage temperature is between -4°F and 104°F (-20°C and 40°C). Similarly, batteries should not be exposed to relative humidity greater than 80% for long periods of time. The storage area should have appropriate drainage and roof cover so that water cannot fall directly onto the battery packaging. Extended storage areas should be compliant with the appropriate local fire code requirements. Batteries should only be stored in approved packaging or on non-conductive surfaces with removal of all nearby loose metal (and other conductive materials) so that accidental shorting can be avoided. Similarly, signs should be posted to alert passers by of the Shock, Fire, and High Voltage risks. If the original Tesla packaging is used for storage, the battery should not be stacked with more than two packages high.

The batteries should not be stored either at a full state of charge (SOC) or completely discharged since both conditions adversely impact battery life. It is recommended that batteries should not be stored untended longer than nine months since battery service life likely will be adversely impacted.

Transportation

Tesla batteries must be shipped in accordance to current service information and policies.

Lithium ion batteries are regulated as Class 9 Miscellaneous dangerous goods (also known as "hazardous materials") according to the International Civil Aviation Organization (ICAO) Technical Instructions for the Safe Transport of Dangerous Goods by Air, International Air Transport Association (IATA) Dangerous Goods Regulations, the International Maritime Dangerous Goods (IMDG) Code, European Agreements concerning the International Carriage of Dangerous Goods by Rail (RID) and Road (ADR), and applicable national regulations such as the USA's hazardous materials regulations (see 49 CFR 173.185). These regulations contain very specific packaging, labeling, marking, and documentation requirements. The regulations also require that individuals involved in the preparation of dangerous goods for transport be trained on how to properly package, label, mark and prepare shipping documents.

Removal From Shipping Crate

The battery is shipped from the factory with safety covers over the high voltage terminals and the service disconnect plug removed. Before removing a battery from its shipping crate:

1. Release latches, remove front cover, then remove upper section from crate.
2. Position shipping crate under hoist.
3. Ensure that the red Power Electronics Module (PEM) positive (B+) cable and the black PEM negative (B-) cable service covers are in place.
4. Ensure that service disconnect is removed. Under normal circumstances, a battery is electrically open circuit and therefore has no external shock hazard when the service disconnect is removed.
5. Ensure that no special test equipment or override mechanisms are in place. Battery test or diagnostics equipment can be used to override safety mechanisms such as the High Voltage Interlock Loop (HVIL). Incorrect usage of these tools and techniques by inadequately trained personnel could cause increased shock hazard. Prior to handling for installation or removal, no test equipment should be attached to a battery.
6. Attach hoist to battery using the upper 4 mounting points ensuring that the chains have equal tension.
7. Remove all bolts securing the battery to the lower section of the crate.
8. Using assistance, carefully begin to lift the battery away from the crate ensuring that all 4 chains remain taught and straight.
9. Position battery onto battery lift table taking care not to damage fasteners during positioning, pay particular attention to the rear battery mounting studs to prevent damage.

Mounting To A Rotisserie

1. Ensure that the rotisserie is in the upright position.
2. Ensure that both left and right locks are engaged.
3. Carefully position the battery onto the rotisserie. Be careful not to damage the 6 rear studs when placing a battery onto rotisserie.
4. Install the 4 M10x25mm cap screws and M10 onto the rear of the battery and tighten until snug.
5. Using assistance, position the top bar onto the battery. Tighten the left and right anchors (torque - 3.3 Nm / 30 in-lbs).

Prior To Installation In A Vehicle

1. Measure the voltage present between the PEM positive (B+) cable terminal and ground on the enclosure and the PEM negative (B-) cable terminal and ground on the enclosure using the probe ports through the service covers. Ensure that voltage is less than 2 VDC. A new or used and undamaged battery will never have voltage present at the cable terminals unless multiple failures are present or safety systems have been overridden.
2. In the event that multiple failures exist (welded contactors, isolation breakdown, mechanical deformity, etc.) hazardous voltages may be present on the PEM positive and PEM negative cables. Measurement for this condition prior to removal of the safety covers ensures no such defects exist. Excessive voltage being present (>25VDC) at these cables is a sign of multiple internal defects or override of safety system through attached test equipment. The service covers will provide protection against electrical hazard and should not be removed unless the measured voltage is below the recommended level. If voltage is above 25 VDC, stop working on the battery immediately and contact a field support engineer for instruction.

Installation Into A Vehicle

After the PEM positive (B+) and PEM negative (B-) cable terminal voltage checks are complete, the battery can be installed into the vehicle. These checks ensure that the battery is safe to handle by trained service technicians.

1. With PEM positive (B+) and PEM negative (B-) cable service covers still in place, route cables appropriately through body-side extension.
2. Follow the correct PEM installation procedure to connect PEM positive and PEM negative cables to PEM high voltage connectors. In order to complete this procedure, the cable service covers must be removed. It is recommenced that the cables be attached one at time with the first cable service cover removed and the cable attached to the PEM high voltage stud before removing the second service cover. These plastic covers add an extra level of shock hazard prevention by providing an electrical insulation layer during handling of unattached cables. These covers also provide two small ports for insertion of measuring probes so that voltage can be verified to be at a safe level before continuing with the installation. Keep protective covers in place throughout repair procedures at all times until it is time to connect the cables to the PEM. This will help protect against accidental shorting if an attempt is made to energize the cables (by closing the contactors) before the cables are attached to the PEM.

WARNING: Removing only one service cover and only exposing one battery high voltage terminal at a time, minimizes the risk of a shock hazard from the PEM positive to PEM negative cables, even if the high voltage cables are accidentally energized or if multiple internal failures are present during the handling of the cables.

Sheet Handling

When removing the sheets from the enclosure or a shipping crate, it is imperative that only designated areas are used to prevent damage to the delicate connections. These areas are:

1. Upper mount area, where the Battery Monitoring Board (BMB) warning label is positioned, using a pinching action from the sides;
2. Front central mount area using upwards pressure;
3. Lower mount area where the front cover fastener hole is located using a pinching action from the sides or using the sheet removal tool ensuring you do not touch or pinch collector plates beneath insulators.
4. Additional handling areas.

WARNING: Cover E-Connector tabs when storing or handling sheets.

WARNING: Insulators cover each side of the sheet and must not be removed without written permission from the Service Support Team.

WARNING: The sheets are heavy and it is advisable that assistance is available whenever the sheets are maneuvered.

WARNING: DO NOT touch the E-connector terminals.

WARNING: DO NOT touch the sheet insulators.

CAUTION: DO NOT use any other area to handle the sheet.

CAUTION: Never leave a sheet unattended while in the vertical position.

CAUTION: Do not bend cooling tubes, or handle sheet by cooling tubes. Ensure coolant tube caps are in place and secure.

CAUTION: Do not push on Battery Monitoring Boards (BMBs) or wires.

Repairs

Workmanship

The following standards must be adhered to when performing repair procedures on the battery:

• Renew ALL fasteners and hose clamps;
• Mark all fasteners that have been tightened using the torque pen;
• Ensure external fastener holes are free from remains of old rubber seal;
• Ensure external terminals are covered at all times;
• DO NOT touch enclosure filters or sheet insulators;
• Ensure that heat shrink on electrical terminals does not affect electrical connection. Trim heat shrink if it is between terminal and fastener if necessary;
• Plug open pipes and connections to prevent the ingress of moisture of dirt and coolant leakage;
• Cover sheets with clean, dry plastic sheeting and secure to inside faces of enclosure when removing traces of old sealant.
• If improper fuse installation occurs, replace the fuse holder.

Thread Locking

Loctite® 242™ should be applied when installing the following fasteners:

• All fuse holder terminal screws;
• Front cover to sheet screws (x11);
• Power Electronics Module (PEM) positive and negative cable clamps;

Screw and Seal Configurations

There are 2 screw and seal configurations on the battery:

1. Sheets to enclosure toe fasteners
2. Sheets to enclosure top fasteners

1. Sheets to enclosure ankle fasteners
2. Sheets to enclosure heel fasteners
3. Front cover to enclosure fasteners

CAUTION: The screw and seal assembly must remain concentric as indicated during installation to ensure a watertight seal.

Electrostatic Discharge (ESD)

ESD is the sudden and rapid transfer of flow of electrical potential between two objects of different electrical potential caused by direct contact or induced by an electrostatic field. Many ESD events occur without a visible or audible spark and can cause severe damage to solid state electronics. Static electricity can be generated by mechanical stresses generating a separation of electric charge, heat generating a separation of electric charge or charge induced charge separation.

Whenever performing repair procedures on the battery, always ensure the ESD cord from the grounded housing of the electrical dropbox is connected to the bare steel on the end of the rotisserie pivot.

CAUTION: If the cord is connected to the electrically insulative orange coating and not to bare metal on the end of the rotisserie pivot, sensitive components may not be adequately protected.

Whenever handling the battery's electronic components (new and old), an ESD mat must be used. The mat incorporates a wrist band, a mat (where removed electronic components should be placed) and grounding wire and clip. The use of the mat helps discharge any static electrical potential that has built up in the body. The mat should be connected to a ground for it to function correctly. Any electrical potential that builds up on the body will be discharged through the strap, into the mat and grounding wire, and then through the clamp to ground.

CAUTION: If the electrical potential is not discharged through the ESD mat, it can build up and then be released accidentally into electrical components causing severe damage.

CAUTION: Ensure the ESD mat grounding wire is clipped to the front cover threaded insert on the enclosure. If the cord is clipped to the electrically insulative black powder coated surface, sensitive components may not be adequately protected.

An ESD mat should be used when handling the following components:

• BSM;
• Any BMB;
• Logic connector circuit board;
• Pre-charge relay.

If any of these components are to be removed from the battery, they should be immediately placed into an ESD bag. These bags are designed to be conductive and generate a 'Faraday cage' around the components to protect them from ESD. The bags must be sealed whenever possible for them to be effective.