Self charging EVs

[dcbwhaley]

Several manufacturers are advertising "self charging" electric vehicles. As far as I can ascertain these vehicles have a petrol engine which drives a generator to charge a battery. The actual traction is provided by electric motors drawing power from the battery.
To my mind a vehicle where the only fuel it uses is petrol is not an EV and should not be advertised as such.

As an aside a Texan correspondence of mine claims he never suffers range anxiety since he tows a trailer with a motor generator set on it so that he can recharge as he drives along

 

[Bletchleyite]

They're normally known as self-charging hybrids, or simply hybrids - the Toyota Prius was the first common instance of the breed. What they offer is regenerative braking, which is not much use if you live in the Netherlands or West Lancashire, but if you spend your days driving around the Lake District or North Wales (or Milton Keynes due to the "accelerate hard, brake hard" nature of the driving) you might find it worthwhile.

Most hybrids are "parallel hybrids" including these, i.e. the engine drives the wheels via a gearbox (usually automatic but doesn't have to be, my mate has a manual Focus one) and a beefed-up starter provides electrical assistance, similar to an e-bike. Almost no cars have railway style electric transmission as it costs more to have a motor powerful enough to handle this as well as the ICE.

 

[Snow1964]

The self charging (from braking or going downhill) is just used to differentiate from plug in hybrids (where you can plug in and charge the batteries whilst parked)

There is another category, range extender EV. Basically electric vehicle, with an engine that can be used to top up the battery. LEVC London taxis are like this, BMW used to make version of i3 too (but dropped it), fell out of fashion as battery range increased.

 

[jupiter]

I've never quite understood the economics of buying petrol and then converting it to electricity, at a less-than 100% efficiency no doubt, then using the electricity to drive the car. Why not just drive the car using the petrol?

 

[Ted633]

I've never quite understood the economics of buying petrol and then converting it to electricity, at a less-than 100% efficiency no doubt, then using the electricity to drive the car. Why not just drive the car using the petrol?

Mechanical gearboxes aren't 100% efficient either. Have no data to say which method is more efficient though!

 

[JohnMcL7]

I've never quite understood the economics of buying petrol and then converting it to electricity, at a less-than 100% efficiency no doubt, then using the electricity to drive the car. Why not just drive the car using the petrol?

They don't charge the battery off engine, the battery is charged by recovering energy while braking. As mentioned above the term is misleading and it's used to to differentiate from plug in hybrids.

There are some cars like the BMW i3 Range Extender which use a petrol engine to charge the batteries but the car is designed to run an electric car most of the time.

 

[Llanigraham]

I drive a self charging Kia Niro and the electric motor certainly isn't "just a beefed up starter motor"!
I can drive it without the petrol engine running at all, even at 70mph on the motorway if conditions are suitable and at other times it augments the petrol engine, so I can easily average well over 60mpg. Certainly the hills of Mid Wales assist in the charging regime!
Just this weekend I drove from here to Penzance and back and averaged 64mpg.

 

[Bletchleyite]

I've never quite understood the economics of buying petrol and then converting it to electricity, at a less-than 100% efficiency no doubt, then using the electricity to drive the car. Why not just drive the car using the petrol?

They do exactly that. The electric bit is about recovering braking energy.

 

[paul1609]

I've never quite understood the economics of buying petrol and then converting it to electricity, at a less-than 100% efficiency no doubt, then using the electricity to drive the car. Why not just drive the car using the petrol?

Test drive one of the latest generation hybrids. Toyota, Renault etc. It really is surprising how much of your journey will be achieved in EV mode with resultant fuel economy in the 60 mpg range no range problems, charging delays or extortionate public charging. If I was in the market for a new car it would definitely be my solution over something like a MG EV. Maybe not once your in the Tesla price range but bottom end of the market definitely.

 

[edwin_m]

I've never quite understood the economics of buying petrol and then converting it to electricity, at a less-than 100% efficiency no doubt, then using the electricity to drive the car. Why not just drive the car using the petrol?

Mechanical gearboxes aren't 100% efficient either. Have no data to say which method is more efficient though!

The engine will be smaller than that in a similar non-hybrid car because the battery will provide a boost on the rare occasions full power is needed. The engine will probably also spend more of its time running near its most efficient speed with any surplus power going into the battery. Both of these will reduce fuel consumption.

 

[Llanigraham]

They do exactly that. The electric bit is about recovering braking energy.

Not neccessarily.
With the ICE running but not needing the full power it also charges the battery in my Niro HEV.

 

[DelW]

As well as in hilly territory, hybrids benefit in urban driving or heavy congestion, since the engine shouldn't be running when stationary or moving at low speed. That doesn't apply to so-called "mild hybrids" which need to have the engine running to move, the electric motor is only for "assistance" and is too small to power the car by itself.

 

[AM9]

As well as in hilly territory, hybrids benefit in urban driving or heavy congestion, since the engine shouldn't be running when stationary or moving at low speed. That doesn't apply to so-called "mild hybrids" which need to have the engine running to move, the electric motor is only for "assistance" and is too small to power the car by itself.

But in reality, all propulsion energy is provided by a prime mover IC engine burning petrol. The only difference is that some of the kinetic energy is temporarily stored in a battery giving 10-20% lower petrol consumption, depending on the battery size and the wieght of the battery and the IC engine. Self-charging is decption on an industrial scale, 'limited energy recovery' would be more acceptable.

 

[E27007]

They're normally known as self-charging hybrids, or simply hybrids - the Toyota Prius was the first common instance of the breed. What they offer is regenerative braking, which is not much use if you live in the Netherlands or West Lancashire, but if you spend your days driving around the Lake District or North Wales (or Milton Keynes due to the "accelerate hard, brake hard" nature of the driving) you might find it worthwhile.

Not correct, there is a lot more than just "regenerative braking" and limited relevance to operating conditions. The hybrid system allows the IC engine to be designed / calibrated / optimised for fuel economy at the compromise of high power output, such optimised IC engines in hybrid vehicles can give high mpg when cruising yet still retain strong performance for acceleration and ascending gradients by supplementing the power of the IC engine with the power of the traction battery and traction motor.
Of such optimised IC engines in hybrids, the fuel-efficient Prius runs a simulated Atkinson cycle IC engine, and the very first hybrids in the UK, the 2000 Honda Insight,the most fuel-efficient car on general sale to the public in the UK and USA, operates at an astonishing 26:1 stochiometric lean-burn fuel ratio

 

[AM9]

Not correct, there is a lot more than just "regenerative braking" and limited relevance to operating conditions. The hybrid system allows the IC engine to be designed / calibrated / optimised for fuel economy at the compromise of high power output, such optimised IC engines in hybrid vehicles can give high mpg when cruising yet still retain strong performance for acceleration and ascending gradients by supplementing the power of the IC engine with the power of the traction battery and traction motor.
Of such optimised IC engines in hybrids, the fuel-efficient Prius runs a simulated Atkinson cycle IC engine, and the very first hybrids in the UK, the 2000 Honda Insight,the most fuel-efficient car on general sale to the public in the UK and USA, operates at an astonishing 26:1 stochiometric lean-burn fuel ratio

All very well when the vehicle is new, but the example of private hire cars in London revealed how drivers misused the 'clean' myth of hybrids.. By running cars (mainly the Toyota Prius) with life-expired batteries continuously on petrol, abusing the principle of zero charges for very low or zero emission. There should.d be an MoT check on battery effectiveness as verification of their hyped low emissions. Failure to reach a standard would force a reclassification to a conventional IC status preventing freeloading in low emission zones.

 

[DelW]

But in reality, all propulsion energy is provided by a prime mover IC engine burning petrol. The only difference is that some of the kinetic energy is temporarily stored in a battery giving 10-20% lower petrol consumption, depending on the battery size and the wieght of the battery and the IC engine. Self-charging is decption on an industrial scale, 'limited energy recovery' would be more acceptable.

They do lower energy consumption, by avoiding wasting fuel during idling and low-speed moves as well as by retaining and using energy which would otherwise be dissipated as heat through the brakes.

But I agree that "self charging" is marketing b*ll*cks and is deliberately misleading.

 

[Harpers Tate]

There is much confusion about these things, not helped at all by clever marketing terms used by manufacturers.

First of all - any non-plug-in vehicle runs entirely on liquid fuel (petrol usually). Now whether that is a simple ICE or some sort of hybrid, nevertheless it is entirely fuelled by burning petrol or diesel. Hybrids attempt to improve efficiency (mpg) by recapturing retardation energy in a battery and reusing it when the car thinks it appropriate. And by allowing (more readily) the engine to stop when it might otherwise be idling. Thus idling waste is saved, and retarding energy is saved.

Most hybrids have their electric motor placed in the traditional power train to assist the petrol engine at times the car thinks it appropriate. You still have a classic transmission (automatic, usually). But some few are emerging where the transmission is electric. (e.g. Nissan Qashqai EPower). The theory is, you get the seamless (no gear changes) behaviour of an electric vehicle, but still entirely powered by petrol. The petrol engine maintains charge state of a battery, and the battery drives an electric motor for propulsion. In these circumstances, the petrol engine can be tuned to operate in a theoretically more efficient manner since it doesn't need to cope with a wide range of rpms to match the vehicle's speed and gear ratio.

After which, there are plug-in hybrids which CAN accept a limited amount of electricity from an external source, so do not entirely run on petrol; and full EVs, of course, which don't use any liquid fuel.

 

[jupiter]

I had a hybrid for about 18 months, or one very expensive service cycle, and used it in a variety of ways.

I accept it may be either the best of both worlds or, for me at least, the worst. As many people, unable to charge at home and unwilling to break a long journey with a 3 hour charge cycle, the vehicle was reduced to petrol-only after about 50 miles or so. And a thirsty thing it was too, I’m lugging about enough fuel for a long journey, petrol engine, electric traction motors and batteries.

The ultimate killer blow was when my local independent German vehicle service place was unable to handle hybrids. One super expensive trip to a main dealer for annual service probably more than wiped out any savings on petrol.

Replaced it with a 320d and I’m getting 57 to 59mpg for my day to day driving, mid 60s on a run of a few hundred miles. The hybrid returned 36mpg day to day, and mid 40s on a longer run.

 

[gg1]

I had a hybrid for about 18 months, or one very expensive service cycle, and used it in a variety of ways.

I accept it may be either the best of both worlds or, for me at least, the worst. As many people, unable to charge at home and unwilling to break a long journey with a 3 hour charge cycle, the vehicle was reduced to petrol-only after about 50 miles or so. And a thirsty thing it was too, I’m lugging about enough fuel for a long journey, petrol engine, electric traction motors and batteries.

The ultimate killer blow was when my local independent German vehicle service place was unable to handle hybrids. One super expensive trip to a main dealer for annual service probably more than wiped out any savings on petrol.

Replaced it with a 320d and I’m getting 57 to 59mpg for my day to day driving, mid 60s on a run of a few hundred miles. The hybrid returned 36mpg day to day, and mid 40s on a longer run.

Which hybrid was that? In my Niro I usually get between low 50s and mid 60s mpg depending on the type of journey and weather conditions. If the circumstances are right I can hit 70mpg.

 

[dcbwhaley]

Test drive one of the latest generation hybrids. Toyota, Renault etc. It really is surprising how much of your journey will be achieved in EV mode with resultant fuel economy in the 60 mpg range no range problems, charging delays or extortionate public charging. If I was in the market for a new car it would definitely be my solution over something like a MG EV. Maybe not once your in the Tesla price range but bottom end of the market definitely.

But my point is that they use petrol as their primary fuel no electricity and therefore are ICE vehicles not EVs and should not be advertised as such,

By the way was my Texan friend bull$h!ting me? Could you charge an EV whist it is in motion?

 

[Bletchleyite]

But my point is that they use petrol as their primary fuel no electricity and therefore are ICE vehicles not EVs and should not be advertised as such,

They're both. The term EV tends to be used for a vehicle capable of being propelled/assisted by an electric motor aside from just starting it.

By the way was my Texan friend bull$h!ting me? Could you charge an EV whist it is in motion?

Provided it's decelerating (or it's a series hybrid), yes.

 

[Sun Chariot]

As many people, unable to charge at home and unwilling to break a long journey with a 3 hour charge cycle, the vehicle was reduced to petrol-only after about 50 miles or so. And a thirsty thing it was too, I’m lugging about enough fuel for a long journey, petrol engine, electric traction motors and batteries.

The ultimate killer blow was when my local independent German vehicle service place was unable to handle hybrids. One super expensive trip to a main dealer for annual service probably more than wiped out any savings on petrol.

Thanks @jupiter and your use-case sounds similar to mine, which I posed at the top of this thread. Forum poster Buzby echoed a very similar sentiment to yours.

Thoughts/advice on buying electric vehicles.

Does any forum reader use a "D segment" sized EV that can comfortably manage a 430 range and wiith the electrics on (e.g. for dark + wet + cold driving)? I have a regular work trip: c.430 miles from the Hants / East Sussex coast to Nottingham and back; and generally a lack of charging provision...

www.railforums.co.uk

 

[gg1]

But my point is that they use petrol as their primary fuel no electricity and therefore are ICE vehicles not EVs and should not be advertised as such,

By the way was my Texan friend bull$h!ting me? Could you charge an EV whist it is in motion?

By talking about towing a trailer with a generator it seems pretty clear he was joking, but it is possible to design and build a system whereby an EV designed for the purpose can charge in motion using inductive charging, though it's only been done at an experimental level so far.

https://www.bbc.com/future/article/...where-electric-vehicles-never-need-to-plug-in

This could be a game changer from the point of view of the adoption of electric buses and goods vehicles where the daily mileages covered are well in excess of cars and where operators won't accept the downtime in the middle of the working day necessary for plug in charging.

 

[Bletchleyite]

This could be a game changer from the point of view of the adoption of electric buses and goods vehicles where the daily mileages covered are well in excess of cars and where operators won't accept the downtime in the middle of the working day necessary for plug in charging.

How much downtime is now required during the day for a typical London double decker electric bus out of interest?

Inductive charging of stationary vehicles is probably easier, anyway. The electric bus trial over 10 years ago in Milton Keynes did that by fitting inductive charging at both termini (and one in the middle just in case) - it worked fine and was only withdrawn for cost reasons (including the entire route, which is annoying as I used to use it, and now it's gone I use the bus far, far less). It did mean an increased vehicle requirement to give them long enough at the termini to charge, but combined with modern higher capacity batteries and improved charging tech that might not be needed any more.

 

[gg1]

How much downtime is now required during the day for a typical London double decker electric bus out of interest?

I honestly don't know, but based on my observation of driver changes, I assume that aside from layovers at route termini, the vehicles themselves are running almost constantly throughout the day.

 

[E27007]

All very well when the vehicle is new, but the example of private hire cars in London revealed how drivers misused the 'clean' myth of hybrids.. By running cars (mainly the Toyota Prius) with life-expired batteries continuously on petrol, abusing the principle of zero charges for very low or zero emission. There should.d be an MoT check on battery effectiveness as verification of their hyped low emissions. Failure to reach a standard would force a reclassification to a conventional IC status preventing freeloading in low emission zones.

You may be referring to vehicles such as the Mitsubishi Outlander where the drivers never charged the traction battery and drove on IC all the time.
as for the Prius, it is news to me that a Prius can be driven without a functional traction battery . From my knowledge of the Prius hybrid synergy system, and checking up on Prius forums, the Prius synergy of an IC engine, a traction battery, Mg1 and Mg2 motor-generators relies on the traction battery for both control and operational purposes, without a traction battery to provide an operating load for the Prius power-splitter drivetrain, the car is not going anywhere. Having been asked to fix a Prius with a dead pack, the car would only limp for a mile or two at a time. Please post any information as to how the Prius can be successfully driven without a traction battery

 

[Bletchleyite]

You may be referring to vehicles such as the Mitsubishi Outlander where the drivers never charged the traction battery and drove on IC all the time.
as for the Prius, news to me that a Prius can be driven without a functional traction battery . From my knowledge of the Prius hybrid synergy system, and checking up on Prius forums, the Prius synergy of an IC engine, a traction battery, Mg1 and Mg2 motor-generators relies on the traction battery for both control and operational purposes, without a traction battery to provide a load for the Prius power-splitter drivetrain, the car is not going anywhere

These cars don't have no battery, they just have ones with a very poor remaining range.

 

[jupiter]

Mine was a 16 reg VW Golf GTE with about 12k on the clock when I bought it from a main dealer. Big, expensive mistake for the way I use vehicles.

 

[E27007]

These cars don't have no battery, they just have ones with a very poor remaining range.

I see, there is an analogy between a hybrid Prius with a deficient battery and IC cars such as diesel engines with the Diesel Particulate Filter removed or internally gutted and petrol IC cars with the catalytic convertor defective
In the case of the Prius an OBDII dashboard warning light will illuminate if the traction battery is life-expired or below a capacity threshold, the dashboard OBDII fault light is an MoT failure point.

 

[paul1609]

These cars don't have no battery, they just have ones with a very poor remaining range.

I think it's an urban myth. The Prius only has a battery capacity of 1.2 kw of which 600 watts is available for EV traction due to the control system design. So as new the range on EV would've been less than 2 miles.