kwh total capacity versus usable kwh. How to compare cars

[Zzzoom3]

I'm still looking for what BMW publishes in this regard.

Warranty
• 8 years / 100,000 miles
• Battery is replaced when State of Health (SoH) is 70% (State of Health to be determined by the Diagnosis System)

See page 19 of this document: http://darrenortiz.com/website_pdfs/BMWi3PG.pdf

Excellent! This seems to indicate that BMW is providing the same warranty for defects and state of charge. Do you agree? In the CA emissions states, that would mean 10 years / 150K miles. This is really good news. Now we just need to see what BMW will do regarding replacement cost following the warranty.

Where did you find this? Thanks

 

[ultraturtle]

Where did you find this?

On page 19 of this document: http://darrenortiz.com/website_pdfs/BMWi3PG.pdf

 

[cove3]

• Battery is replaced when State of Health (SoH) is 70% (State of Health to be determined by the Diagnosis System)<<<<

Isn't the real question whether the battery will ACTUALLY decline to 70-90% within the warranty period? Because 90% means 72 mile range, 80% 64 miles, and 70% 56 miles. So even if the warranty doesn't kick in, you're moderately to severely handicapped.

What's required is to see some kind of i3 time/range deterioration curves for several different usage environments eg hot weather states, miles driven etc

Ron

 

[Zzzoom3]

• Battery is replaced when State of Health (SoH) is 70% (State of Health to be determined by the Diagnosis System)<<<<

Isn't the real question whether the battery will ACTUALLY decline to 70-90% within the warranty period? Because 90% means 72 mile range, 80% 64 miles, and 70% 56 miles. So even if the warranty doesn't kick in, you're moderately to severely handicapped.

What's required is to see some kind of i3 time/range deterioration curves for several different usage environments eg hot weather states, miles driven etc

Ron

The battery capacity will decline. But your question is a good one. I can't imagine I'll have 90% after 8 years. So for me, I'm anticipating the news about what these replaceable modules will cost when needed.

 

[ultraturtle]

...I'm anticipating the news about what these replaceable modules will cost when needed.

To give you a very rough guideline, Nissan just became the first EV manufacturer to announce the cost of replacement battery packs - $5,500: http://www.greencarreports.com/news...for-replacement-with-heat-resistant-chemistry

$229 per kWh is very inexpensive by today's standards, and it is an improvement over the original pack, although it requires return of the original pack. Making the reasonable assumption that the pack lasts for 100,000 miles, its cost per mile is half that of the gasoline that would be used in a similar car (the 35 mpg Versa, assuming gas at $3.85/gal). The i3 would cost more per kWh because of its more expensive chemistry if replaced today, but your replacement needs should be well into the future. Lithium Ion technology has plenty of room for advancement, and experts expect the recent trends of energy density doubling in 12 years, and the price per kWh dropping by half in 8 years to accelerate (http://ec.europa.eu/dgs/jrc/downloa...industries/20130926-eco-industries-miller.pdf).

That's just Lithium Ion. Other battery technologies are advancing as well.

 

[jadnashuanh]

When you consider the nature of the car, and BMW"s research on how their first EV trials went, the typical 34-mile daily commute is still easily within range of the battery, even if it degrades to that 70% figure. The thing is not an ICE, or a replacement for one, even with a REx (IMHO), and expecting it to be, is just asking for disappointment. It was designed to be a city car, for generally short trips at lower speeds. That it can go fast and longer than the typical user's needs is a bonus. My typical one-day use is a maximum of maybe 15-20 miles, so I could probably go several days between plugging it in. I kept my ICE for when I may need to go beyond the i3's abilities. When the USA gets a good DC quick charge network, I might consider taking it further, but waiting for it to recharge on ac just isn't viable unless you were planning a stop at that time (say shopping, work, recreation, etc.).