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Current State of Battery Tech

Posted: Sun, 19 Apr 2015, 17:01
by bidgeeeman
Hi,
I haven't posted here for quite some time now and just wondering what the current state of battery technology and pricing is? A couple years back I was looking at doing an EV conversion using a lead acid bank and could only dream of having a set of Lithium's.

What is the pricing like nowadays?

Thanks
Bidge

Current State of Battery Tech

Posted: Mon, 20 Apr 2015, 00:33
by jonescg
About $500-600/kWh including BMS and relevant taxes for LiFePO4.
About $1000-1200/kWh inclusive for decent lithium cobalt/manganese/nickel cells.

Current State of Battery Tech

Posted: Mon, 20 Apr 2015, 20:30
by Richo
There is also a shift from prismatic and cylindrical to pouch cells.

Current State of Battery Tech

Posted: Mon, 20 Apr 2015, 20:44
by bidgeeeman
Thanks for the responses....it's been so long since I looked at all this so please forgive my ignorance regarding Lithium batteries as I am not very tech savvy but what would a standard EV conversion for a light vehicle using the LiFePO4 be cost wise?

I remember I was looking at using about 8 - 10 lead acid batteries last time?

Thanks
Bidge

Current State of Battery Tech

Posted: Mon, 20 Apr 2015, 20:48
by Johny
Welcome back David.
I've found that for a 1000kg vehicle you get about 8km for every usable kWh. (At 70km/h and 25°C.)

Current State of Battery Tech

Posted: Mon, 20 Apr 2015, 20:58
by bidgeeeman
Hi Johnny
So for around $1000 you would get a bank of LiFePO4, as per jonescg's post earlier, that would get you around 150 k's range?

Thanks
Bidge

Current State of Battery Tech

Posted: Tue, 21 Apr 2015, 02:01
by offgridQLD
"Hi Johnny
So for around $1000 you would get a bank of LiFePO4, as per jonescg's post earlier, that would get you around 150 k's range?"

No that's not correct.

They were saying roughly $500 - $600 for one KWH of lifepo4 battery (including battery related accessory's)

The very rough rule of thumb given for a 1000kg car at 70kph in 25c weather was one KWh of battery you will have 8km of range.

So using the above to have a 80km range. You will need 10kwh of lifepo4 cells. At $600 that's $6000 I think that's a little optimistic as you wouldn't use 100% of the battery and you would need roughly 20% in reserve. So for that 80km range light car its more like $7200.

I have a simpler rule of thumb view. Most small cars used as commuters will need at least a 16kwh battery to have a rough practical max range (100km) and long life (not deep cycling during shorter 50 - 60km trips) from the bank.

20kwh if you are pushing 100+km trips regularly will give you some more breathing space. Any more lifepo4 in a small car than 20kwh starts to become a weight burden without huge gains.

16kw will cost you roughly $10,000 and 20kw $12,000.

Have at least a 10k budget for battery's and battery assessors. The only cheaper way is if you use 2nd hand OEM cells or you are building a car with a very limited range.


Kurt

Current State of Battery Tech

Posted: Tue, 21 Apr 2015, 02:14
by bidgeeeman
So after 4 years we are really in about the same state as we were cost wise as far as lithium's go?

Maybe I should leave it for another 4 years :)
(Just kidding).

Many thanks for the info
Bidge

Current State of Battery Tech

Posted: Tue, 21 Apr 2015, 02:25
by offgridQLD
Probably more expensive than a was a few years ago (due to the low Australian $ at the moment)

Though with the benefits if economy of scale. There are some big players getting into battery production like (Tesla) along with a lot more salvageable OEM cars getting around so prices could come down.

Though your purchasing 15 - 20 kwh of energy storage and that's not 20kg of potatoes. That kind of energy storage has value like any other commodity as it's very useful.

people always say "battery's are expensive"...in comparison to what?


kurt

Current State of Battery Tech

Posted: Tue, 21 Apr 2015, 21:05
by Richo
bidgeeeman wrote:So for around $1000 you would get a bank of LiFePO4 that would get you around 150km range?


Well you wouldn't get that range on lead anyway.
You would need 30kWh at around 800kg.
30-50km is about all you get out of lead before a car will be too heavy.

Assuming you could have 30kWh of lead that is ~$5,500 for 2 years running.
or $22,000 for 8 years (~3000 cycles).
That is ~760 headway cells eqv (24kWh) and about $18,000 for the same ~8 years.
So over 8 years the lithium would be cheaper than lead by $4k or $500 per year.

I'm sure there are deals around on lead and lithium that still make the numbers above valid.
So the point is start saving and don't worry about the lead.

But if you were making an EV for driving to the corner store once a fortnight use lead...

Current State of Battery Tech

Posted: Tue, 21 Apr 2015, 23:27
by offgridQLD
"But if you were making an EV for driving to the corner store once a fortnight use lead..."

Even then in the corner shop example your just better off with a very small lithium battery. Whats the saying ...."Lead is dead"

Kurt

Current State of Battery Tech

Posted: Tue, 21 Apr 2015, 23:37
by bidgeeeman
So what is the life expectancy of the lithium's? Is it worth looking at the used ones at all?

Bidge

Current State of Battery Tech

Posted: Wed, 22 Apr 2015, 03:09
by T1 Terry
If you want to make up a really cheap lithium battery, check out a You Tube series Electric Samba. A great watch and you can follow his exploits building 3.7v cells from recycled lap top batteries. A ton of work, but cheap as chips if you place no value on your time.

T1 Terry

Current State of Battery Tech

Posted: Wed, 22 Apr 2015, 21:05
by Richo
bidgeeeman wrote: So what is the life expectancy of the lithium's? Is it worth looking at the used ones at all?


Even at 3k cycles this is normally until they reach 80% of their original capacity.
So a 10Ah only has 8Ah left after 3000 cycles.
There is likely to be a small drop in the peak power output.
But still very usable after this point on most applications.

It's more likely that the battery will hit the "life expectancy" before cyclic use.
This is a result of vibration, oxidation, temp and natural breakdown of chemicals inside the battery etc.

Most seem to quote 5-8 years if at all.

Used lithiums will be hard to find.
Usually only as a result of an ev project not finishing or the thing they were in has been damaged.
But most have been in good condition.
Best to check when they were initially bought or made.

Current State of Battery Tech

Posted: Wed, 22 Apr 2015, 21:08
by Richo
offgridQLD wrote:Even then in the corner shop example your just better off with a very small lithium battery. Whats the saying ...."Lead is dead"


I tend to agree but for a cheap ev where you are unlikely to reach the cycle limit lead still can be an option.

Current State of Battery Tech

Posted: Wed, 22 Apr 2015, 21:12
by Richo
T1 Terry wrote:If you want to make up a really cheap lithium battery, check out a You Tube series Electric Samba.


https://www.youtube.com/results?search_query=esamba+EP


Current State of Battery Tech

Posted: Fri, 24 Apr 2015, 17:49
by acmotor
It does depend on the distance to the corner shop. 28km round trip for me. Image

+1 for the high discharge rate small pack lithium rather than ever going LA again.

I recently upgraded a friends gofer to lithium but had to leave the LA in place as ballast so it wouldn't tip over.

Current State of Battery Tech

Posted: Fri, 24 Apr 2015, 21:36
by Richo
Ha ha true.