[Closed] 18650 Li-Ion ex laptop cells

The best way I've found to regenerate those cells is to pop them in the microwave for about 11 minutes on full power.

give me a hand lugging this thing outside peter....

These won't be protected cells as the protection would have been in the circutry of the laptop battery. I had about a dozen or so but binned them in the end after reading about them going bang in the night. Got some protected xtar cells now.

if you compare them to a torchy cell you will probably notice they are shorter, by about 3mm.

Can these be used as normal 18650 cells in a torch?

Yep.

Voltage will be the same.

Obviously Im not going to be charging or discharging them anywhere in the house/shed just in case.

I did go through a phase of only charging Li-ion cells in a metal box, but I've got lazy and just leave them charging in the kitchen over night. I figure the cats will deal with a fire if one occurs 😉

I was more worried that without protection the unregulated discharge through the torch may upset them?

I figure the cats will deal with a fire if one occurs

How do you make a cat go "woof"? 😉

I was more worried that without protection the unregulated discharge through the torch may upset them?

Most cheap torches eg DX ones have no protection and you just need to switch if off once the beam goes a bit yellow. Not damaged a LiIon cell yet using them....

Whereas I've had loads of Li-ion battery packs have one cell die even though the packs have protection circuitry etc....

hmm, interesting.

I shall have go at charging them with my crap chinese charger, outside, and see what kind of life I can get out of them.

I know a load of them came from a knackered Dell original battery, but maybe it was just one or two dud cells.

I know a load of them came from a knackered Dell original battery, but maybe it was just one or two dud cells.

Multi-meter will tell you in a few seconds, they just collapse and have a tiny voltage across them.

oh, didnt know that.

OK, will go and grab the multimeter in a sec.

... and that was the last anyone saw of him.

How dangerous are these type of cells? I could probably 'harvest' quite a few from old laptop batteries but don't want something dangerous in the house.

I could probably 'harvest' quite a few from old laptop batteries but don't want something dangerous in the house.

No more dangerous than a laptop unless you start throwing them on the fire, microwaving them or shorting them out.

... and that was the last anyone saw of him.

I was just passing Malvern when I saw this in the distance:

[img] [/img]

Ok, so from a storage point of view the only special measure that needs to be taken is ensuring they don't short out?

What about charging? Do they need to be treated differently to protected cells? i.e. will they blow if left to charge indefinately?

What about usage? Do they need to be replaced with a fresh battery when they start getting low on power to avoid damaging them?

Thanks

Apologies for the slight thread hijack OP!

Ha!

Right, the red ones are from the DELL and original Asus batteries and are all showing +3.7v.

The blue ones look lik ethey have been recylced once already - they came out of an aftermarket long life battery pack for an ASUS netbook. They are showing between 1.4v and 3.2v so Im just test charging a pair of those (1.48v and 2.49v) and see how they fair.

the red ones all work fine in the torch so I will probably charge them all up under supervision and stick them in the shed for grabbing as and when. its more than I need and unfortunately despite them being surplus, of course I cant post them to anybody 🙁

I suspect the 1.4v one is dead and won't charge.

Lithium-ion is charged at approximately 4.2 ± 0.05 V/cell except for "military long life" that uses 3.92 V to extend battery life. Most protection circuits cut off if voltage greater than 4.3 V or temperature greater than 90 °C is reached. Below 2.50 V/cell the battery protection circuit may render the battery unchargeable with regular charging equipment. Most battery circuits stop at 2.7–3.0 V/cell.

except mine dont have a battery protection circuit. Its possible the crappy cheap charger does,

Anyway, theyve both been on for 10mins, let me go and measure them....

EDIT: both now showing 3.4v so they're obviously getting some charge, we will see if it's much AH though.,...

Ok, so from a storage point of view the only special measure that needs to be taken is ensuring they don't short out?

Very unlikely to short them out by accident unless you keep them loose in a metal tin and shake then around.

What about charging? Do they need to be treated differently to protected cells? i.e. will they blow if left to charge indefinately?

Any Li-Ion charger you buy will have a max voltage cut off to prevent over charging. The manual will also say don't charge unsupervised as there is always the very small chance they catch fire. If they're going to catch fire it will be when charging.

What about usage? Do they need to be replaced with a fresh battery when they start getting low on power to avoid damaging them?

Over time their capacity will diminish, as with any battery / cell. At some point this will be noticeable and you'll just want longer life so replace them Eg my Electron Terra 3 bike light now only manages about 25 mins on full beam (should be 2 hours).

Its possible the crappy cheap charger does,

It will have, it would be negligent to sell one without as any Li-ion cell with explode if you just keep charging it for too long.

it has over charge protection, but not sure if it has lower a cut off voltage.

ANyway, back to those infernal landrover doors. Got two more to finish - Worst. Job. So .Far 🙁

WIll report back on the charging later.

Unprotected cells are risky in that lion really doesn't like being overcharged.

If you're going to use them I'd suggest using a decent charger and a protective bag/box

If you're making them up into your own packs, google "lithium pcm" and you find and add your own protection.

Unprotected cells are risky in that lion really doesn't like being overcharged.

If you're going to use them I'd suggest using a decent charger and a protective bag/box

If you're making them up into your own packs, google "lithium pcm" and you find and add your own protection.

Ok thanks. I've got an XTar MP1 single cell charger which according to the specs will prevent over charging by monitoring the cell. I'll try charging some unprotected cells outside just in case.

I've got an XTar MP1 single cell charger which according to the specs will prevent over charging by monitoring the cell.

All chargers prevent over charging, you wouldn't be allowed to sell one which didn't....

footflaps - Member

Its possible the crappy cheap charger does,

It will have, it would be negligent to sell one without as any Li-ion cell with explode if you just keep charging it for too long.

I guess you dont have much experience buying from China.
I used to regularly buy chargers from China and they all topped out around 4.18v, now a few years latter, they range from 4.20v - 4.50v!!

My advice if you buy a Chinese charger, use a multi-meter to measure the voltage its putting out and to NEVER charge batteries untended or while you're sleeping.

You can get an IMAX B6 charger quite cheaply, its what I use to test my cells to find out if they're worth keeping.

Id tested my cheap-chinese one last year as there were reports of some coming in too low, but mine runs at 4.17v on one side and 4.07v on the other.

PS where do I dispose of ones I dont want to keep?

PS where do I dispose of ones I dont want to keep?

Your local recycling centre will take them.

I shall take some there then.

Those crappy ones that were on charge are now at 4.24v and holding their charge. Nice and bright in the torch.

I thought 18650 cells were supposed to be 3.7v?

I thought 18650 cells were supposed to be 3.7v?

All cells' voltages drop as they discharge, some by a lot, some by a very tiny amount. Hence they tend to quote a 'nominal' cell voltage for the type of cell as it's simpler than 2.4 to 4.1 etc etc.

In telecoms, where Lead Acid batteries are used we have a charging voltage of 54v for 4x12=48v Nominal battery, but the kit normally works down to 36v or less as the cells discharge, so a 48v battery is actually 36 to 60v!

I use old lappy 18650's to charge my mobile things while I'm camping. You can get cases that double as a charger that house four of the little fellas and will charge phones and tablets.

neilsonwheels - that sounds like a v handy use for a surfeit of old 18650s.
[s]got any links?
[/s]

god Im lazy. 😳

first hit on ebay
http://www.ebay.co.uk/itm/18650-USB-Battery-Charger-Box-Case-Mobile-Power-Bank-5V-1A-fr-Iphone-Samsung-/291052105413?pt=LH_DefaultDomain_3&hash=item43c40eaec5

Neilson - thanks for that tip. Ive just got a few different version of those to make the most of these spare cells. A couple of 1x for bro for his phone, and a 2x and a 4x for trips away etc and charging the Nexus 7 (2A)

brilliant idea, cheers!