4EV Safety Type Mass Produced Conversions Location Home Work Public Who OwnerFirst Responders
5EV Safety Type Mass Produced Conversions Location Home Work Public Who OwnerFirst RespondersConcernElectricityFireAccidentsOther
6EV Safety We are early adopters of this technology We need to use the technology safelyWe need to encourage others to use the technology safelyWe need to understand the RisksWe need to be able to explain the facts to others
7ChangeMuch of the worry about EV’s relates to Change Many people don't want any change Others accept it as they see the benefits Some may have business to loose Some just enjoy being negative Simple factual responses and answers are best.
8First RespondersFirst responders worry about there safety In ICE vehicles they cut the battery cable In Ice vehicles there is no high voltage In Ice vehicles it is easy to tell if the engine is on Training and experience is what is needed. When Air bags were first used there was unfounded concern about them exploding in a fire.
9Electricity Electricity is dangerous and needs respect. We have electricity in our homes and we are safe.It is safe because:There are codes and guide lines for constructionProducts are tested and listed UL or ETC for safe operationBuilding inspectors verify parts are used as intended.
10Electricity The EV stores it electricity in a battery pack. The voltage is typically 120 volts DC to 400 Volts DC.The battery can store 10 to 40 KW-Hours of energy.That is a lot of energy. My home uses 5 KW-Hours of energy per day.My home could use 38 KW-Hours of energy per hour but it does not.One gallon of gasoline contains about 33 KW-Hours of energy.People feel safe with gasoline because it has been around for so long.There are gasoline car fires.
11Electricity in the CarEV’s are electrically isolated form from the chassis and it is groundedElectricity must flow through a body.The isolation prevents this.
12Battery in Production EV’s Man years of engineering, testing and DesignDesigned to be safe, long LifeIn a PackageTouch SafeContainmentCrash worthyServiceableBattery Management ControlDisconnecting means for service and first respondersStandardized wire colors to identify high voltage
13Battery in Production EV’s Designed to be safe, long LifeIn a PackageTouch SafeContainmentCrash worthyServiceableBattery Management Control
14Batteries in Conversions Goal is often get as many batteries in as possible Initial goals are often to be safe and long Life serviceableIs it really touch safe?Will the batteries and any fluids be contained?Is it crash worthy?Will it be serviceable?
15Batteries in Conversions What is crash worthy? The Converter’s Guide to the Galaxy and EV Conversions By Richard W. Marks, A complete book about how to plan a safe conversion Battery mounting needs to withstand forces 20 times the battery weight in the forward and side to side directions. Things will bend and plastic covers will move. Plan for shorts or damaged wiring. Batteries should never be in the cabin with the occupants Even though they may appear low cost Lead Acid and AGM have so much mass and spill potential they should not be used today.
17Batteries in Conversions Fuses and circuit breakers Rated at circuit voltage or more 𝐼 2 T ratings Disconnects, normal and Emergency More than one? Andersen Connectors Orange Wires for all high voltage
18Batteries and FIREAny time there is lots of energy available fire is a possibility.Wiring failuresCircuit failureWater or fluid failuresCrash damageOne leads to another
19Batteries and FIREThe Volt Fires. Weeks after a Crash test the car burns The crash test caused the battery coolant to leak in the battery pack and got the electronics wet and the pack failed and burned. Coolant or liquids are not a problem with the 12V battery in present cars due to low voltage and chemistry. It is new technology and it would be great if every problem could be anticipated but it is the real world.
20Batteries and FIREConversion Fires. Yes, there have been many conversion fires Neal Young’s LinkVolt project car. In the movie “Revenge of the Electric Car” Gadgets fire looks to focused at the battery pack. Most seem to happen in the night with unattended charging.
21Batteries and FIREConversion Fires. Unattended charging and BMS often seem involved. These systems must have redundant safe guards to prevent over charging. They must take temperature into consideration and stop if a problem is detected. They must fail in the off state. My personal issue is poor quality BMS wiring. Telephone low voltage solid wire that can break or chafe leading to a serious problem with no warning. Ever notice automotive wires thick insulation?
22Batteries and FIREWhy so much on Fires. Lithium ion batteries are safe at the rated current levels and at the rated temperatures. They do have organic solvents inside that are flammable at higher temperatures. The real problem is over charging. The Li+ suddenly changes from ions to metal when over charged. The metal can short out a cell and cause a hot spot. The pressure goes up and the battery vents or bursts. One hot cell heats the next. Li metal is very active and can separate water to H² and OH, generate heat and burn. Water may not put the fire out.
23Batteries and FIREWhat can we do to reduce the risk. Like production cars only use 70 or 80% of the pack capacity. This leaves a safety gap at the ends of the charge cycle. It also extends the number of cycles the batteries will provide. Recognize this as a serious problem and use the best construction and wiring around the battery pack. I would want a smoke detector in the garage even if I trusted the car!
24J1772SAE J1772:2010™ charging brings several levels of safety to charging and the electrical interface. There are extra costs with this extra safety There is also the advantage of a common compatible connector for most cars.
25Level 1Typically implemented as VAC1440Watt-HourAt 200 Watts/mile so 1 hour of charge hour gives 6 milesLevel 2Typically implemented as VAC5500 Watt-HourAt 200 Watts/mile so 1hour of charge hour gives 27 milesAt 80 amps 1 hour of charge hour is 19,200 Watts giving 96 miles
26Why are EVSE so expensive SafetyOut in the weatherVandalsAbuse like driven onLiabilityIt’s new!
27The CarCharger is in the car for level 1 and 2 All electrically isolated form from the chassis and it is grounded
29J1772 Vehicle Inlet Shrouded pin and sleeve design Separated Touch safeProtected from damageStarting to mateInterlocking protectionGround firstFully matedFull contactLong Interlocking path
30EVSEThe EVSE does not power the cable or connector until it is latched and the car requests power
31J1772 Pilot SignalEVSE is UL listed and covered by NEC Article 625
32Pilot Details When disconnected the Pilot is +12VDC Connecting Adds the diode and R2 which reduce the +12VDVC to +9VDCThis starts the PWM signal, 1KHz, Positive PWM width represents currentI = duty cycle X Amps, then changes.Close S2, +9/-12V changes to +6/-12 and contactor coil gets power and car gets power.
33Proximity Tells the car it is connected. It is OK to charge Inhibit motion
34Level 3 Fast DCDirect connection to the battery V2G possibilities
35Level 3 Fast DC CHAdeMo is the most established Tokyo Electric Power Company, Nissan, Mitsubishi and Fuji Heavy Industries500 VDC at 125 Amps
36Level 3 Fast DC SAE J1772 Level 3 Combines the J1772 Level 1 & 2 connector with the Level 3GM, Chrysler, Ford, Toyota, Honda, Nissan, and Tesla.Expected to be 600VDC at 200 Amps
37EMI and RFIElectric things do produce EMI and RFI Some people worry about it other don’t There are standards modern products Vehicles must comply to be safe Designs limit the emissions no to interfere with others or radio. Shielded wires Conversions emissions are likely higher.
38Mechanical Issues Always use the hand brake Consider chocks Vehicle WeightBrakesWeight balanceTo much power
39Electrical Issues Respect the battery pack Disconnect the pack before workNever work on electrical parts while chargingInsulate toolsLong sleeves and gloves make it safer.Never work alone
40Charging Stations, EVSE Public or business locationsLook it over for damage its outsideCheck the statusTry to advise someone if it’s downPlug inCheck that its functioningUnplug and move the car when doneWhat about that ICE car?What about unmarked 120V outlets
41Charging Stations, EVSE Place the cable to safe and obviousPut the cable backConcern and liability about people tripping on a cable in use or improperly stored
42Charging Stations, EVSE Use them when you can to show people they are needed.
43EV Safety David Kerzel Modular EV Power LLC http://modularevpower.com/