EV’s – serious question for those in the know.

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  • #162684 Reply
    DougieB
    Participant

    As a trained diesel fitter and confirmed petrolhead, I remain to be convinced by the case for EV’s, but as an engineer, I’ve been pondering the technology behind them and have two questions. If anyone can provide answers, I’d be obliged.

    1. On an ICE, the batteries are charged by a standard alternator so why is there not a similar system fitted to EV’s? If it were driven off the drive train, it would at worst provide a top up and/or power the vehicle systems such as lights, wipers, heater, etc. At best, particularly on long journey’s, it could recharge the battery.

    2. Given the power generated by wind has become a standard source of energy, why are wind turbines not fitted to EV’s? I’m not talking about windmills on the roof, but a simple unobtrusive device akin to a Dyson blade working in reverse and using forward momentum to power a generator. It could be fitted behind the grill or even underneath the vehicle.

     

    Current car: VW Tiguan R-Line Tech auto in nice shiny black. ­čÖé

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  • #162685 Reply
    Intranicity
    Participant

    On your 1st question, most if not all EV’s have 2 batteries, the main traction battery and a standard 12v one. ┬áThe traction battery is recharged either by plugging in or regenerative braking and powers the motor and A/C only. ┬áThe 12v one though is charged like it is is an ICE via an alternator. ┬áThis battery usually covers all the traditional tasks of a car battery, with the exception of the Air conditioning.

    The second question, I would guess that the extra weight and cost of such a system, just isn’t practical for the amount of power it could provide. ┬áThe most logical (to me) system would be fitting cars with solar roofs, I believe the Hyundai Ioniq5 has this as an option, but for some reason not a UK one.

    Previous Motability Cars
    2006 - 2009 Skoda Superb VR6 2.0tdi
    2009 - 2012 Citroen C5 2.0tdi VTR Nav
    2012 - 2015 Nissan Qashqai 1.5dci tekna
    2015 - 2018 Ford Kuga 2.0tdi Titanium X
    2018 - 2021 BMW 220d X drive 2 Series Active Luxury
    2021- Hyundai Kona Electric Premium SE

    #162687 Reply
    Rhodgie

    Probably best to email the technical department of Tesla to get proper answers but in my best estimate….

    1. It isn’t needed because it sort of already does, the 12v is charged from the traction battery, the traction battery gets some of its charge through regen. Plus it only needs to top up the 12v when it’s required. With an ICE there is no other way to recharge the 12v than when the engine is running but you are constantly running the alternator so for 90% of the time it is an unnecessary drag on engine power.

    2. Probably the financial costs but I doubt it’d get back the energy it lost in extra drag… EVs are already very efficient and an external wind turbine isn’t going to help when most people aren’t going very long distances. Some folk reported economy gains just by blocking up the small vents at the front used to cool the aircon radiator, for serious distance or speed attempts they’ll tape over any panel gaps too while opening a window even a fraction causes a huge aerodynamic drag.

     

    Both of these ideas may have a use in another setting but I doubt it’d help with a regular user just going to work, shopping, visiting etc.

    #162689 Reply
    Brydo
    Participant

    Its strange that the two main reasons for ICE and BEV cars AA call outs is blown tyres and faults with the 12V battery.

    So similar but so different lol.

    The only person who got all his work done by Friday was Robinson Crusoe.
    Anything i post over three lines long please assume it is an article lol.

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