# Polymer Li-Ion cheaper than lead acid?



## Tommahawk (Sep 28, 2008)

What do you make of this

http://www.all-battery.com/polymerli-ionrechargeablebatteries.aspx

r they selling lithium ion polymer cells for cheaper than equiv lead acid solution?


----------



## joseph3354 (Apr 2, 2008)

hardly,50 ah 3.7 v for $299 ? lifepo is less expensive than that.


----------



## TX_Dj (Jul 25, 2008)

Yup. 14.8v @ 50Ah (4 * 3.7v) = $1196 (4 * 299)... nowhere near cheaper than lead.


----------



## abudabit (Sep 18, 2008)

Tommahawk, when calculating total energy of a battery you need to figure out the watt hours, don't just look at amp hours. Watts are of course volts x amps, and watt hours are of course volts x amp hours.

So do the equation watt-hours / price when doing comparisons. It will return a watt hours per dollar (or what ever currency) ratio.

Of course not all watt hours are created equal when you consider the intricacies of batteries...


----------



## TX_Dj (Jul 25, 2008)

For example... 3.7v @ 50Ah = 185 Wh, but 12v @ 50Ah = 600 Wh.

However, the lithium will get more of those watt hours to the motor, whereas the lead will not, thanks to high amperage and Peukert's Law.

There probably is a formula to figure out where the "breaking point" is for that, if you know the peukert exponent for the two batteries... even still, the cost per 'observed' watt hour is well beyond my budget at this time.

Though it has been argued that if LiFePO4 lives up to the promises, it will well exceed the lifespan of lead, and could end up being more economical in the long run. Even though I like being on the cutting edge of gadgetry, I don't so much like being on the bleeding edge... that's far more costly.


----------



## Gary Sconce (Oct 4, 2008)

TX_Dj said:


> ... I don't so much like being on the bleeding edge... that's far more costly.


LOL! Nice comment... Colorful but correct.


----------



## Tommahawk (Sep 28, 2008)

two articles

Lead acid that gives li-ion a run for its money

http://www.businesswire.com/portal/...d=news_view&newsId=20070305005030&newsLang=en

*Ener1 Sees 50% drop in Li-Ion price at mass production*

// September 5th, 2008

http://www.sequence-omega.net/2008/09/05/ener1-sees-50-drop-in-li-ion-price-at-mass-production/


----------



## david85 (Nov 12, 2007)

Lithium is almost at the point where it could replace lead acid even for car starting application. The price is already comparable when you compare the energy storage, and projected life expectancy. But purchace price is, I'm sorry to say, still much higher. Projected life expectancy will take time to prove.


----------



## saab96 (Mar 19, 2008)

Tommahawk said:


> http://www.businesswire.com/portal/...d=news_view&newsId=20070305005030&newsLang=en


That's good for the military, assuming they haven't just been scammed. Doesn't do us any good.


----------

