Stevei3 said:but isolating the 'run-flat' experience from its context, like in the article you linked, is a highly tendentious way of making headlines IMHO.
Steven
Jeremy said:Ken
Obviously this makes a huge difference to the outcome - can you point me to the "49 mile" reference?
TomMoloughney said:You simply slow down to 60 or 65mph for a couple minutes if you see the SOC dropping down near zero and the REx will then be able to get the SOC back up to a safer level.
kentheteaman said:TomMoloughney said:You simply slow down to 60 or 65mph for a couple minutes if you see the SOC dropping down near zero and the REx will then be able to get the SOC back up to a safer level.
Hello Tom,
Would have all the specifications of Rex engine - how to use, when to switch it, when not to use it ect.... That will be helpful.
regards,
ken
Jeremy said:Sounds like an opportunity for a freelance software hack.
In the consumer electronics industry it's common for products with identical hardware to offer different capabilities in different countries for marketing reasons.
I remember a Sony video camera that hard certain input/output facilities disabled in European markets - although they could be restored by a "illegal" software download from a US source.
Similarly, my Lexus has a stupid safety feature that prevents the satnav being reprogrammed, or the main phonebook accessed, on the move - even for a passenger.
I believe there's a published hack for defeating this - although I haven't risked it.
Time (and human ingenuity) will tell!
Sranger said:Jeremy said:Sounds like an opportunity for a freelance software hack.
In the consumer electronics industry it's common for products with identical hardware to offer different capabilities in different countries for marketing reasons.
I remember a Sony video camera that hard certain input/output facilities disabled in European markets - although they could be restored by a "illegal" software download from a US source.
Similarly, my Lexus has a stupid safety feature that prevents the satnav being reprogrammed, or the main phonebook accessed, on the move - even for a passenger.
I believe there's a published hack for defeating this - although I haven't risked it.
Time (and human ingenuity) will tell!
If BMW is smart, this info might fall off of a truck some where....
I think it is 100% silly to not allow us to engage the REx early. The reason is simple. NO ONE is going to buy a $40-$50K electric car and NOT use the EV mode as much as is possible. That is the ENTIRE POINT of the vehicle...
Heck the #1 discussion of most VOLT forms is how to NOT use any gasoline. It has become and game/obsession for most owners....
Tom:TomMoloughney said:The range extender is a 650cc two-cylinder gasoline engine developing 34 hp (25 kW). It will automatically turn on when the state of charge dips below approximately 5% and it will hold the charge at that level (it doesn't increase the state of charge so you can't use it to actually charge the car). On European models you can manually turn it on once the state of charge dips below 75%. The reason you may want to do that is to hold the state of charge at a level higher than 5% if you know you'll need a lot of power later to say, climb a mountain or if you are going to be driving in a zero emission zone and want to keep from depleting your charge before you get there.
I realize that you addressed this question to Tom, but perhaps I can help answer some of this. While I don't have any specifics, I can offer up some general information, which pertains to the overall design. The REx is limited to a maximum of about 25 kW of output power. Since this would not result in a satisfying driving experience, it has been long assumed that the REx will be augmented with battery power for the use cases you mentioned above. Unfortunately, if the battery reserve is limited to 5%, this only translates to about 0.6 kWh of usable capacity. Enough to climb 500 feet or drive about 3 minutes at the top speed of 95 mph instead of 75 mph, which is what the REx can sustain indefinitely on flat terrain.rclams said:
Is it correct to assume that the in US Rex mode, the 5% remaining charge will help support temporary, high kW needs, such as acceleration away from a light, pulling out to pass or a short, steep incline and that the Rex engine/generator would then recharge the battery back to the 5% level?
Yes, it's not recommended to dip that low. Having said that, the drivers of other lithium-ion powered vehicles have not been able to see much of a difference in practice. Also, manufacturers typically test the batteries with a very aggressive test cycle, and discharge them completely on each run. We know that these batteries can sustain many hundreds, if not thousands, of deep cycles. While shallow cycling is recommended for improved longevity, it's difficult to discern much difference from occassional deep discharges in the field.rclams said:But, wouldn't this high current cycling near the bottom of the voltage range of the battery cause accelerated wear and tear on the battery?
While I don't have any specifics, this has been the case with other commercial EVs. There typically is about 2% charge left, when the vehicle stops dead after turtle mode. This charge is not accessible to the driver, and it's supposed to prevent bricking of the battery in the event that it's not recharged soon after the car stopped.rclams said:Or is this last 5% of "usable" storage sufficiently buffered by the "hidden/unusable" capacity of the battery?
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