Lithium Battery "Care"

Post by **woody** » Thu, 10 Apr 2014, 15:20

From about 40 seconds this gets relevant.
This is a 10Wh battery, now imagine an EV battery of 20,000Wh, and another car instead of a sledgehammer.

Think about this when you are designing your pack and where to put it in your car.

Post by **evric** » Thu, 10 Apr 2014, 15:28

That's one reason why we don't use Lithium Polymer...

Post by **poprock** » Thu, 10 Apr 2014, 15:29

disclaimer " do not try this without adult supervision"

Post by **Johny** » Thu, 10 Apr 2014, 15:30

evric wrote: That's one reason why we don't use Lithium Polymer...

Exactly.

Post by **jonescg** » Thu, 10 Apr 2014, 16:28

Err, most automotive cells are in fact lithium polymer. They might not be lithium cobalt cells like the ones in smartphones, but they will short, puff and explode when punctured. A decent puncture-proof enclosure and an isolated venting system for a battery compartment is essential!

Post by **offgridQLD** » Thu, 10 Apr 2014, 17:08

Its not just lithium cobalt thats dangerous.

https://www.youtube.com/watch?v=d_TnsHu2u4c

Kurt

Post by **acmotor** » Thu, 10 Apr 2014, 17:32

Re the guy smashing an S5. Sorry, what an idiot. What was proved ? The phone is tough ?
He could just have smashed the battery ... Note he didn't do that with the phone assembled.

So a human, a car , a house , a plane suffering the general impact the phone received would be soooooo already destroyed that the consequence of the battery going Phiz seems quite irrelevant.

The guy selling the sheds... To start with it is about charging then the shed is labelled battery disposal ?
What better way to make batteries of dubious condition safe... Collect them all together in one place so the potential damage is greater ! Did I see spill trays and forced ventilation and a built in fire extinguishing system, maybe C02 ?

Re battery packs in EVs, it is noteable that the pack in the iMiEV has had enourmous attention to crash survival, perhaps unlike my conversion

A tank of 98 octane would be spread in a ball of flame well before the iMiEV pack was a fire issue.
IMHO

Post by **offgridQLD** » Thu, 10 Apr 2014, 17:45

I guess what I was getting at it just because a uncontained lipo cell went fizzz fizzz fizzz as it vented after being hit with a sledge people get all worked up. The lead acid car battery can give off a bigger fizz/bang

than the lipo . The silly vented sheds were just a unfortunate addition to the first 1/2 of the video.

I agree the a crash in a EV that would relate to that sledge hammer hitting the phone would be like driving your car into a solid block of steel the size of a house at 80 km h or so with the battery strapped to the bonnet.

People don't worry about liquid gas tanks in there cars they can make great explosions.

Kurt

Post by **celectric** » Thu, 10 Apr 2014, 18:10

jonescg wrote: Err, most automotive cells are in fact lithium polymer.

Chris, I know you are a fan of 'alternative' chemistries, but LiFePO4 is by far the most common lithium cell type for EV conversions, is not lithium polymer, and is notable for its safety.

Post by **jonescg** » Thu, 10 Apr 2014, 18:57

For sure, LiFePO4 is more tolerant to abuse than LiCoO2, and I would definitely not recommend anyone build a conversion full of HobbyKing LiPo. Decent quality cells on the other hand are the way of the future.

That said I think you will find that a boot full of CALBs would go up much the same if a spear went through the side of a cell, especially if they were fully charged. In the end, any chemistry is capable of doing serious damage. People are only driving around with LiFePO4 in their conversions cause it's cheap and hit the mass market long before LiCoO2 did. With more amps on tap and better energy density, I reckon that had hobby LiPo been around and at the same price as CALBS, performance would have outweighed safety in that decision.

Post by **offgridQLD** » Thu, 10 Apr 2014, 20:26

Its funny I have just taken my electric recumbent trike out of mothballs a little while ago. I had been powering it from cheap lithium cobult cells. Unfortunately having stored them for a long time (over a year) at a much higher charge than I had intended to in a reasonably hot shed A few of them were sick.

Anyhow I dug around the shed and found a few good cell packs and made up a temporary pack for the trike.15s,5Ah 60ish volts. With this tiny brick of batteries about 1/2 the size of a tissue box I went for a 15km ride around the local area, what a blast to be back on the trike again real go kart style fun and a good acceleration punch.

At home again I started thinking about replacing the small pack with a larger 20AH pack I had befor, more for the range. This is when I started to think about the stack of old Headway 10AH lifepo4 cells I had laying around. I gathered a few together stacking them into a brick of roughly 60v 20AH

Yikes I had forgotten just how big and heavy they were. Then I did a 2nd smaller configuration of just 10A - 60v that was still big and heavy. I then had to consider the C rating of the lifepo4 at just 10ah they would not have been happy though the 5AH brick of cobalt wasn't fussed.Battery building with lifepo4 was a little depressing.They can stay powering my beer fridge in the shed.

Again holding the tiny 5ah 60v brick in one hand that had just pushed myself and the trike over 100kg combined 15km around the block and driven real hard the motor smoking hot, both front disks tinkering away as they cooled from all the 2700w blast up and down every hill and opportunity I could find. Yet the lipo was only warm. Sure it has some safety and longevity advantages but I just couldn't go back to lifepo4.

Relating to the phone that very same ride had unfortunately ended in my iphone slipping out of my pocket at 70kmh on Mt nebo road smashing the screen. $30 later I had a replacement screen kit and the tiny screwdrivers out. After pulling the back cover off the first of many steps is to pull the battery out. Holding the little black chewing gum packet size battery in my hand (that was also available replacment for just $6) I had to marvel at moden battery tec. This little battery is over 4 years old and gets cycled every day to around 10-20% SOC and considering it's size gets some heavy discharge rates in a modern smartphone. 4 years is near on 1500 cycles +. On several occasions its been accidentally placed in the direct sun in the car 45C trip to adelaide last year had me pick up the phone and almost burn myself. It's had a hard life yet still no (noticable performance drop) Im sure there is some but to think what this little battery had done faultlessly considering its replacement cost is a modern marvel we all take for granted.

Kurt

Post by **Richo** » Thu, 10 Apr 2014, 20:50

Yeah all shades of red

LiFePO4 CALB puncture

LiFePO4 Headway puncture

lithium manganese dioxide(Leaf)

Lithium Cobalt(lipo)

Post by **Johny** » Thu, 10 Apr 2014, 21:02

Nice little compilation Richo.

Post by **offgridQLD** » Thu, 10 Apr 2014, 21:11

Would be interesting to see the leaf cell struck with the hammer.

Kurt

Post by **Stiive** » Fri, 11 Apr 2014, 16:03

Lol.
Now I'm even more interested...

Post by **acmotor** » Fri, 11 Apr 2014, 16:53

Perhaps it was removed as it was a stupid act of want'n destruction ?

or perhaps Apple complained coz their phone broke after the first hit when they tried to copy the significant scientific research ?

Post by **Richo** » Fri, 11 Apr 2014, 20:34

Well it wasn't spam.
Perhaps a scam but I don't know how they would illegally profit from it.
So must be commercially deceptive content.

I don't know - it seemed pretty clear cut to me.
Hit it with a hammer it blows up.
Who would have thought there was deceptive content on YouTube

I guess YouTube really believe those over unity motors are real.
And those plans I can buy are legitimate.
And they honestly believe that aren't scamming people.

Yeah I reckon they got paid to remove it...

Post by **Richo** » Fri, 11 Apr 2014, 20:37

offgridQLD wrote: Would be interesting to see the leaf cell struck with the hammer.

I reckon the guy was pretty ballsy repeatedly stabbing it with a screwdriver.
I doubt the end result would be different but it would be nice just for proof.

Post by **winners** » Sun, 13 Apr 2014, 06:30

Yep, all energy storage can be dangerous.

Chemical, mineral or even water(although that could be both).

When polymer came on the scene, I could not believe the change in energy density and I am still blown away with the performance and stability if treated correctly.