How stands the electric vehicle? Is it yet economically viable? Karrier Motors are in the vanguard of development
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PROGRESS to date in electric vehicle design was summed up by David Brain of Karrier Motors at Drive Electric '82 — an event organised by the Electric Vehicle Association together with Eastern Electricity.
Through Dodge, Karrier has been extensively involved in electric vehicle development leading to the 50-Series being available as a factory line-built option complete with electric traction although the work began with the Walk-Thru Silent Karrier.
The initial design standards for the Silent Karrier were set by the National Freight Corporation and Dodge claims that for the market sector in question, these standards were correct.
For many delivery conditions within built-up areas, a maximum speed of about 65km/h (40mph) is quite sufficient. The ability to accelerate up to around 30mph in the same time as a conventional diesel of equivalent payload is also regarded by Dodge as essential to achieve traffic compatability. Accordingly a target time of 20 to 23 seconds was adopted for the 030mph time.
One of the main stumbling blocks to greater electric vehicle usage has been range. The original Walk-Thru based vehicle had a range of 55km (35 miles) and Dodge now has a target of 72 to 88km (45 to 55 miles).
For the follow-on to the original Walk-Thru, Dodge went for the S 66 model in the 50series range which has a gvw of 6.6 tonnes. This was necessary to achieve a body/payload capability of around 2.4 tonnes, indicating just how much is being carted about in batteries.
The motor is supplied by EDC and is a separately excited compound wound DC unit rated at 50kW. It is of frameless construc
tion which Dodge claims saves 90kg (2001b) in weight and about 40 per cent in cost compared with the Silent Karrier system.
The Chloride batteries are of the high energy density lead/acid type rated at 420Ah. The battery unit incorporates 80 cells and weighs just under 2.1 tonnes. The Chloride Autofill system has been incorporated which allows the entire battery block to be topped up in 10 to 2 minutes.
The transistorised controller i produced by Chloride Legg an varies the applied voltage acros the motor and the curren through the motor. High-spee electronic switches are use which vary the percentage c time where the battery is directl connected to the motor. Higl speed in this context mean opening and closing thi switches up to 500 times pe second. This varies the averagl voltage so the power h controlled by the timl relationship between "on" am "off".
The first production batch o BO vehicles is now in the pipelino and 30 have already been sold The significant part about thi electric Dodge is that it is pro duced on the normal assembll line at Dunstable alongside its ic mgined counterparts. The only tern fitted off track is the batery pack because this would under access to the rest of the ;hassis when on the line.
The batch of 80 came about )ecause of the funding made ivailable by the Department of ndustry.
The vehicles are being sold hrough the normal Dodge iealer network who can also Irovide the servicing with ;upport from Chloride on their rarticular bits. On the warranty ide, the vehicle is covered for 2 months on a limited mileage )asis with the batteries covered )y Chloride's own warranty. his is for two years' full waranty with a further two years' .overage based on the reduced ralue of the battery.
Dodge admits that the indusry is at a stage of development Mere the initial cost of the Ilectric vehicle is high and canlot be justified commercially as in economic proposition. This as necessitated some financial ,ssistance from the Department if Industry which allows the )odge/Chloride vehicle to be iriced at £14,625. This was done in the basis that future compolent development plus an inreasing differential between the ost of oil and electricity would lean that the electric vehicle should be able to stand on its own feet in approximately five years.
Compared with the equivalent Dodge S46 (which for reasons already explained has the same payload as the electric S 66) fitted with a conventional box body and suitably discounted, the cost ratio between electric and diesel is approximately 1.7:1.
Dodge claims that this ratio is bearable on the basis that over eight years the whole life costs of both vehicles are the same. Some figures quoted by Dodge on possible savings are £713 on fuel, £160 on vehicle excise duty (the electric vehicle is excempt) and £55 on MoT preparation.
This amounts to £2,124 over eight years as a new set of bat teries would probably be re quired during that time. If an assumption is made that oil prices will rise by about two per cent per year then this would account for a further £410 over the eight year life. Taking all these factors into account the electric vehicle is left with an additional cost of £402 per year.
Dodge maintains that this extra cost can be more than jus tified by the potential savings in maintenance and quotes around £1,250 per year for maintenance for this type of vehicle.
The electric vehicle concept eliminates a number of prob lems immediately. For example, there is no fuel system to freeze (memories of the recent winter have not yet receded), no clutch or gearbox problems and instant starting. Dodge cost estimates predict that a 30 per cent saving in maintenance will eliminate the £402 mentioned earlier.
Dodge is certainly very aware that in spite of all the claimed advantages for the electric vehicle, the high initial outlay can present a problem. To overcome this, Chloride — in conjunction with Barclays Mer-. cantile — has developed a bat tery leasing programme, which means that the initial vehicle price will be close to that of a conventional chassis, ie £8,000 against £7,400. The battery lease is over four years and involves eight sixmonthly payments (in advance) of £825. To ensure that the battery is properly maintained Chloride will undertake a mandatory inspection schedule, the cost of which is already included in the figures quoted.
The operator is still required to ensure that the batteries are correctly operated and maintained. This requires for example that he must provide a topping-up trolley for each depot at a price of £295 — and this is NOT included in the leasing charge.
All the interested parties believe that the leasing schecile will be useful for many operations where capital availability is restricted.
One of the claims being made with increasing frequency by the electrical vehicle supporters is that the real price difference between oil and electricity will diverge making fuel costs for ic engined vehicles relatively worse. Dodge claims that this together with reducing initial costs and consequently lower financing costs will eliminate the need for Government funding.
One problem encountered by Dodge in building the electric powered 50-Series was finding space for the batteries. This immediately eliminated the short wheelbase version.
As far as the future is concerned, improvements in motor designs and other driveline components will help to reduce costs, according to Dodge, which also makes one further prediction: that the electric vehicle has assured continuity of fuel, which cannot be said for oil powered vehicles.