Lithium ion batteries

[CaddmannQ]

I've been doing a lot of reading about Lithium-ion batteries and more I read the less I like them

Just last night I was trying to attach the accessory battery pack to the back of a portable DVD player.

Fortunately it was not charged. Because one of the cells ruptured when I pressed it into place.

There was nothing Sharp in the case to puncture it. It ruptured from flexure. When that happened it swelled up & the plastic case split open. The thing started getting warm and I took it outside and stuck it in a bucket.

Fortunately the state of charge was low so it never passed enough current to get hot. There were two cells in the battery case & the one which remained unruptured I purposely ruptured by poking it with an ice pick.

The reaction was immediate but not very strong because the battery was discharged. These were two pretty good sized cells inside a plastic case, each about the size of an iPhone.

Also lithium ion cells need to be especially regulated when used in pairs and multiples. You're only going to get as much performance out of a lithium ion battery pack as the weakest cell in the pack. (Not the cell with the lowest state of charge but the cell with the lowest potential capacity to accept charge) If you charge the strongest cells in the pack up to the maximum it will exacerbate this effect, in that the pack will seem dead, but if you remove the offending cell it will come back to life.

Unfortunately lithium ion cells will not all produce the same exact amount of power and it varies by as much as several percent.

 

[ripjack13]

Where are you getting them? Online from amazon? Junk. Those things are always old and lost their charge.
I get mine here....
http://www.batterywarehousedirect.com/2.html

 

[dieselmudder]

Lithium polymer is very popular in the RC hobby. Yes they are somewhat "high maintenance" but when properly maintained work very well. I can run a 4wd, 1/10 scale truck, on a trail run for over an hour on one battery. A bucket of saltwater is the proper disposal for lithium batteries. Once they "puff" Just drop them in saltwater for 24 hours.

Sent from my SM-G360V using Tapatalk

 

[Rossignol]

Dang, I checked the battery warehouse link and didn't see what I need. I'll try another search but what I've got is 3.7v lithium ion.

 

[Daryll]

Even the original batteries in Iphones have a limited life... I had an old Iphone 3 that I'd left in a drawer when i upgraded, but then my Mother-in-law needed a replacement phone so i looked for the old Iphone 3... the battery had swollen to twice the thickness and cracked the screen.

 

[Rossignol]

^Oh snap! We've got a couple old iPhones laying around now that we haven't looked at in a long time.

Also, I did some looking and it seems I can source those 3.7v batteries from a few other places including Walmart.

 

[Pawpaw]

Your batteries sound like 18650 size.

They're available in a wide range of capacities and, unfortunately, quality. Be sure you buy only "protected" batteries. They have a little "coin button" on the + end that has circuitry to limit charging and discharging current, which is the primary cause of overheating, fire, & explosion.

I have some EFEST 18650's which are a good brand. Mine are rated at 2600mAh, 3.7v, 40A max pulse discharge and 25A max continuous discharge.

 

[CaddmannQ]

. . . A bucket of saltwater is the proper disposal for lithium batteries. Once they "puff" Just drop them in saltwater for 24 hours.

Thank you for this DM.

 

[CaddmannQ]

Well I fully expect several things to happen in the near future, meaning a year to 18 months.

Rechargeable alkaline battery technology is going to come online fast to challenge the more expensive lithium ion technology for devices which do not need it. This will drive down the price of lithium ion.

Production of Lithium-ion batteries is going to ramp up continually driving the price down due to competition within Li makers.

The price of the charging and controller technology will come down as well.

Lithium ion battery prices have dropped by a factor of about 10 within the past 3 years and I think current prices will drop over 50% in less than 18 months.

That still makes them about twice as expensive as that acid batteries in terms of power output per dollar, but at least not 10 times which is what they have been.

 

[John A.]

I once shot a defective cable box convertor that had one of the large button cells in it, and inadvertently hit the battery backup battery that was in it due to power loss.

NOT a reaction that you would want to happen indoors or on your person. I promise

 

[CaddmannQ]

. . . A bucket of saltwater is the proper disposal for lithium batteries. Once they "puff" Just drop them in saltwater for 24 hours . . .

I wanted to thank you for this again and mention that I thought saltwater would destroy a lithium ion battery, but in a dramatic manner.

Mine really didn't do anything. Maybe they fizzed a bit but those batteries were pretty well discharged.

Anyhow I'm hoping that my lead-acid batteries will prove sufficient, and last a while, until the price of lithium ion batteries comes within reason.

Right now I could replace my pack with Lithium-ion batteries for about $4,000. The reduction in weight would allow me to carry an extra passenger. Right now my battery pack plus the battery box itself which I built to contain it, weighs approximately 400 lb. A Lithium-Ion setup would weigh half that.