Quote:
Originally Posted by redpoint5
38,050 views. I'm not sure your threshold of appropriate interest, but I'm impressed.
|
Oh!
I shoulda checked that. That is impressive!
Still it's strange to me that there are so few posts.
Lithium batteries should already in the same shops as Lead Acid car batteries as an upgrade/alternative and std equipment on new cars IMHO.
The price of lithium battery packs for cordless power tools points to prices being about the same for the same energy density here, meaning economies of scale have come into play.
People are taking advantage of that.
eg: This RYOBI 40-Volt lithium-ion high-capacity battery to E-bike 'adapter'
https://github.com/pittxprojects/ebike
Quote:
Originally Posted by redpoint5
Most fuel consumption isn't spent overcoming inertia though, but drag. The most drag is caused by aerodynamics, followed by mechanical friction. Weight is perhaps the 3rd most important factor, and further diminishes in importance for hybrids, EVs, and PHEVs that are capable of capturing the majority of inertial energy when decelerating.
|
In city, stop-go driving in a std gasoline car?
I've seen stats saying that 98% of trips are under 50 miles, but no maths on overcoming inertia vs aero drag vs rolling resistance.
Google AI overview after a quick search:
https://www.google.com/search?q=In+c...t=gws-wiz-serp
When driving in a city, the energy spent on overcoming inertia is greater than the energy spent on overcoming aerodynamic drag or rolling resistance:
https://www.sciencedirect.com/topics...g%20resistance.
https://www.combustion-engines.eu/pd...20real%2Dworld
https://www.uselessgroup.org/sectors...st%20important.
Here's a breakdown of how fuel energy is used in a car:
Transmission and driveline
Slightly more than 5% of fuel energy is lost in the transmission and other driveline components.
Inertia
About 6% of the energy that reaches the wheels is used to overcome inertia.
Aerodynamic drag
About 3% of the energy that reaches the wheels is used to overcome aerodynamic drag.
Rolling resistance
About 4% of the energy that reaches the wheels is used to overcome rolling resistance.
And who want's to 'look after' and park etc a boat tailed car on a shopping outing..?
DBD seems far lighter and more practical to me.
Regen in a EV or HEV certainly complicates the question!
I'd say that's a question for a different topic.
Quote:
Originally Posted by redpoint5
Finally, it seems the supercapacitor momentum fizzled out a while back. New and better products haven't come out, and prices have gone up. Tesla purchasing Maxwell hasn't resulted in anything new except elimination of some of their product line.
I'm bummed there hasn't been much more to talk about on the subject, which is probably why we started talking about LiFePO4.
Finally, none of my newer vehicles use a starter motor, and therefore have low "cold cranking" needs. Buffering a LiFePO4 battery with a supercapacitor is unnecessary when it only needs to close a high voltage contactor long enough to power up the DC/DC converter.
|
Ye... It's a pity.
There is a good bit of info on
DIY 'roll your own' supercap on the net.
Not all of it BS as far as I have seen/can tell. So there's another topic for the forum.
In an EV it seems a shame not to buffer the batteries with supercaps.
Capture more regen energy and save the battery from high discharge rates when accelerating.
Perhaps the power added doesn't offset the extra weight and space.
Apparently this is called Hybrid Energy Storage System (HESS) and is a thing still.
All this could use its own topic.