Friday, 24 July 2009

Frequently Asked Questions for EV upgrades. FAQ.

I often get asked questions about EV conversions so I thought I would gather many of the answers. below.

Electric Vehicle Upgrades: FAQ.

What kind of car should I get upgraded?

Essentially any car can be upgraded however some lend themselves to a simpler, easier and cheaper conversion than others. Here are some rules of thumb to follow:

  • Look for a vehicle that is pre 2002 as the integration of the electronics tends to be simpler. Once the petrol motor is removed, the engine management computer will complain and this may affect other computers in the vehicle such as the Dashboard, Security and Air Conditioning ECUs in many modern vehicles.
  • Upgrade a vehicle that you would like driving. You should hope to get many years of good service from the vehicle.
  • Find a vehicle with no rust, panel damage and a good interior. You don’t want to have to spend thousands of dollars on panel and paintwork
  • The vehicle weight and load carrying capacity must be considered. A vehicle that weighs less than 1100kg and have a GVM (Gross Vehicle Mass/ maximum loaded weigh) of 1400kg or more. The difference between these weights will determine how many and how large the batteries can be and also the number of passengers. 85kg per passenger must be included when calculating GVM.
  • For a DC motor upgrade the vehicle must have a manual transmission.
  • For a slightly more expensive AC motor upgrade you should choose an automatic only if the motor comes with suitable reduction gearbox and differential.
  • A front wheel drive vehicle often has more possibilities for the battery location in that they may be installed under the rear set due to the lack of a driveshaft beneath the vehicle. In a rear wheel drive vehicle, the battery pack will invariably need to be split over 2 or more locations including luggage space.

How far can I go?

The answer is that it depends, but I will give a typical example.

  • A car typical small car weighing 1100kg with a 144V, 100Ah battery pack will have a range of about 80km to 80% discharged
  • The same small car using 160Ah batteries will have a range of about 120km. These would be the largest practical batteries you could use.
  • If the vehicle is heavier, terrain is very hilly, or you are travelling at high speed, the range will be less.
  • The effect on range of heating and air conditioning will be 5-15% depending on use.
  • The number of passengers or load will have a small effect on range. In stop start traffic this will be between 5-15%.
  • The larger the vehicle, the less range it will have. A 1600 kg vehicle with a 144v, 100Ah lead acid battery pack will have a usable range of 35km.
  • A 2000kg vehicle with 144V 200Ah Lithium battery pack will have a range of about 50km.

How Fast can I go?

· Upgraded vehicles are usually capable of freeway speeds of 110km/hr.

· Some upgraded commercial vehicles may be limited to 90 – 110 km/hr for city use, giving increased range.

Battery life cycle.

· Lithium batteries have a cycle life of 3000 cycles if not discharged below 80% capacity. This is about 11 years if the vehicle is driven 5 days a week. The capacity is viewed on a specially designed battery ‘fuel’ gauge. More advanced gauges may also show a distance to empty. If the battery is discharged below 80% capacity frequently the cycle life can be as low as 1500 cycles.

· Good Lead acid batteries that are designed for electric vehicles have a cycle life of about 400 cycles to 80% discharged or 800 cycles to 50% discharged. 800 cycles equates to about 3 years.

How long will it take to charge my batteries?

· A typical 144v, 100Ah battery pack will take 6 hours from fully discharged when charged from a typical 10A power point. Realistically the duration will be less as the batteries will never be fully discharged.

· We also have fast chargers available that can charge the 100Ah pack in 3 to 4 hours.

· Larger 160Ah batteries will take proportionally longer to charge 8-10 hours using a standard 10A power point.

How heavy are the batteries?

· A 144v 100Ah lithium battery pack will weigh 144kg

· A 144v 160Ah Lithium battery pack will weigh 252kg

· A 100Ah Lead Acid battery pack will weigh 340kg for a 120v system or 413kg for 144v.

· The additional weight of the batteries is largely overcome by the removal of the fuel tank, exhaust, radiator and the petrol engine.

· In some vehicles, especially older models, the suspension springs may need replacing to retain original ride height.

How safe is an upgraded vehicle?

There is significant effort put into the safety Eve Motor Group upgraded electric vehicles. Following are some of safety features.

· The vehicle fully complies with the Road Transport Authorities National Code Of practice # 14 for electric vehicle conversion.

· The vehicle complies will all Blue Slip (NSW) requirements

· A crash sensor in installed that will disconnect the motor in case of an accident

· Fuses between all battery banks and a circuit breaker is installed in case of a controller or high current cable fault.

· All battery compartments, battery restraints and component anchor points are designed to comply with the G force requirements in case of crash and roll over.

How much will it cost to charge?

The charging cost primarily depends on how far you have driven. Let’s work it out.

· Say our car averages 180Wh/km. We drive 50km so we use 9kWh of electricity.
Battery chargers are about 85% efficient so this means that we might use 11.25kWh to charge.

· In a residential, Using power at normal retail rates(say 20c/kWh) this might cost $2.25, or 4.5c/km

· Residential off peak rates during 10pm to 6am (.6c/kWh) might cost 1.35c per km

· Large business pay as little as 7c peak and 4c off peak

· You can buy plug in a power meter from Jacar Electronics Part number MS6115 for about $40 that will calculate your charging costs. Alternatively for about $100 a kWh meter can be installed in the vehicle.

How do I charge using cheaper off peak power?

· If you have an older meter box, ask your electrician to install an off peak power point in your parking space. This will only be powered between 10pm and 6am (longer on weekends) and charged through a separate meter at off peak rates.

· If you have a newer smart meter, you can add a timer available from electrical suppliers on the power point you use for charging and set it to only turn on when lower priced electricity is available.

Should I keep the clutch?

· In my opinion, Yes. Many mechanically minded people will boast they can drive a car with a manual gearbox without a clutch, and in fact driving an EV without a clutch is not difficult. However, everyone that drives your vehicle in the future will be used to it, so it is best to leave it in so that anyone familiar with driving a manual can drive the EV.
It is important to remember that it might be possible (depending on the speed controller) to over rev the motor and shorten its life, or worse, destroy it. This can be overcome by the use of a rev limiter most modern speed controllers. All Eve Motor Group controllers have a rev limiter built in.

· One concern of keeping the clutch is that the bearings in the motor are not designed for axial load, however according to the motor manufacture; the bearings are able to take the axial load created by the clutch plate and springs.

Can I tow a trailer?

· Towing a trailer with an electric vehicle is possible for short distances but is not recommended due to the additional load on the batteries.

Where is the nearest upgrade centre?

· Our conversion centre is located in north-west Sydney; however we are planning to open other upgrade centres around Australia.

How much does it cost?

· Please contact the Eve Motor Group via the online form to proceed with an estimate based on your requirements. http://www.evemotorgroup.com.au

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