Nice, any improvements in battery technology are great news! 2008 could be a very exciting year for the ev world.

Sounds good. But you gotto wonder why charge cycles on most new batteries are hovering around 2000. If you charge your batteries every day you get a lifespan of about 5 years. Sounds a bit like the planned obsolescence of old school manufacturing. I'd like to see 5k cycle minimum - or better the 20k + cycles claimed by Alti.

But you gotto wonder why charge cycles on most new batteries are hovering around 2000. If you charge your batteries every day you get a lifespan of about 5 years.

2000+ cycles seems pretty good compared to the current NiMH technology at what, ~600 cycles. What percentage of people would drive their (P)HEV vehicles in a way such that they would average 1 charge cycle per day for 5 years straight? Furthermore, current control systems in HEVs try to prohibit deep cycling, so I think it is safe to say that cycling can likely be limited in the future enough to give the battery pack a reasonable lifespan.

I agree 2000+ sounds pretty good to me.

My concern would be more about cost and power density.

What happens at the end of the battery's life - is it sent back to the manufacturer to recycle the materials, or just dumped ?

@mahoni: Definitely recycled.

re 2000 cycles:

Your going to get a lot more than 5 years out of these when you consider that they are talking about deep cycles. Shallower discharges have much less of an impact on the life of the batteries. By the time you get through 2000 cycles, your probably starting to run up against calendar life issues at 10yrs+

Bob,

The drive pattern is for a family car/truck that commutes daily and is plugged in at home. Each time the charger engages it provides some level of charge thus meeting the definition of a "charge cycle."

While 2k cycles represents an improvement over NiMh - Altair's spec sheet indicates 10-15,000 "deep discharge" cycles. Are they so far ahead of everyone else? And if you have to purchase new batteries at 5-6 years how much extra cost is added to vehicle amortization, 25-40%?

Also when evs become more usual in the streets it wont be dificult to find parking lots with charging capabilities, using them u can get less deep dyscharges, adding therefore more lifespan to your batteries.

regarding recycling the battery...

Not needed for Valence batteries. They are made of "rust and dirt" nothing toxic in 'em.

They have already been approved by California to be thrown away in landfills.

Green as hell....why doesn't anyone seem to know this?

It will be interesting when people start selling PHEVs secondhand. How will people know how much of a beating the battery has taken.

You would want some tamper proof charge recording system to tell people if it has lived 5 years of deep or light discharges.

mahonj

you make a good point, I guess hopefully 1st gen users will be the adopters, proving that the tech can be durable. 2nd gen can worry about the 2nd hand infra stature but yes its the many issues that surround the EV.

I'm debating if I should run my prius to the ground with a PHEV or buy a new volt, since mpg ranges for gas/elec are usually within the 150 mpg range, but I have belief that due to the more powerful electrical components of the volt, the 200 mpg barrier can easily be achieved.

Or for some, none at all.

altair is that far ahead of everyone else. Take lithium ion batteries used in laptops. If the time to discharge is 3 hours or longer, you will get about 250-350 cycles out of a set. The is a problem with the charge cycle, the temperature and several other factors. tesla motors said that they have solved that issue to get 4000 charges out of the same batteries which often die before 100 charges.

A123 has about 15,000 deep discharge cycles too at a high current draw, but they don't charge well faster than 1C.

one thing to look at about altair though, is that they haven't shipped many packs, ie less than 50 last time I checked.

altair is that far ahead of everyone else. Take lithium ion batteries used in laptops. If the time to discharge is 3 hours or longer, you will get about 250-350 cycles out of a set. The is a problem with the charge cycle, the temperature and several other factors. tesla motors said that they have solved that issue to get 4000 charges out of the same batteries which often die before 100 charges.

A123 has about 15,000 deep discharge cycles too at a high current draw, but they don't charge well faster than 1C.

one thing to look at about altair though, is that they haven't shipped many packs, ie less than 50 last time I checked.

The question isn't really cycle life it's calender life, some early adopters are seeing -10-15%/year. Altair is claiming to have solved this but there's really no way to accelerated test this is there?
The only thing to do right now is overbuild to compensate.

What's the $/W numbers on this? Is it available?
Also, I saw where at TEKbattery.com they are claiming a 3000 cycles and 5 yrs warranty similar battery. Also, great discharge demo - realworld/no powerpoint.