unprotected 14500 as single use?

[balou]

Has anybody ever used unprotected 14500 as single use cells?
They are cheaper than lithium AAs, and thanks to their higher voltage generally run more efficient with buck/boost circuits than 1.6v AAs with boost circuits.
Also, many lights run much brighter.

So.. if I throw them away after one use, could they still pose a risk? Anybody ever measured their runtime in comparison to other cells?

 

[Morelite]

Are you talking about 3.0v lithium primaries like the Lisun 14500 pictured below?


If you are, where do you get them? I haven't been able to find them anymore and even when I did they cost more than the Engergizer lithium AA's.

 

[balou]

No, I'm talking about 3.7v nomial li-ion rechargeables
http://www.dealextreme.com/details.dx/sku.19771
2 pieces for $3.99

Locally, Energizer Lithiums are $5 a piece, on 4sevens about $2.30... the unprotected Li-ions are only $2/piece


edit: you could probably find 14500 size primaries on farnell.com - but most of those are for low-drain memory retention applications (tens of mA)

 

[Morelite]

But why would you throw away a rechargeable cell after one use. You need the charge them before use so why not keep recharging them?
The only reason to trash them would be if you overcharged them or ran them too low.

 

[csshih]

they normally come uncharged, though... so you would have to charge them up initially.

 

[PeaceOfMind]

Just because you only use the cell once doesn't mean you are any better protected from the dangers that a protected cell is designed to prevent. As others have pointed out, you'll want to charge them initially anyway (most decent Li-Ion cells will ship with 40-50% charge). So you have all the risks associated with any charging and discharging mishaps, with no protection.

So basically, yes there is still a risk, and as others have said, why use a rechargeable cell only once in any case?

 

[45/70]

I think balou is looking strictly for a less expensive alternative.

The problem I see is that even a fully charged 14500 LiCo cell doesn't have as much capacity as an L91. That is taking into consideration the voltage difference.

14500 3.7 Volts x 700mAh = 2.59 Watts

L91 1.5 Volts x 3000mAh = 4.5 Watts

Yes, it'd be a bit cheaper I guess, but you'd have to replace cells more often. And then, as everybody said, you'd have to charge them when you got them anyway. So really, IMO it wouldn't be practical to use them this way.

balou, do you buy your L91's online? Usually you can find them for around $2 a piece here in the US, locally, and close to that, if not cheaper online.

Dave

 

[TranceAddict]

why throw it after single use while it is designed to be recharged and re-use? do something for the environment. lithium-ion cell is very toxic to the nature

 

[balou]

But why would you throw away a rechargeable cell after one use. You need the charge them before use so why not keep recharging them?
The only reason to trash them would be if you overcharged them or ran them too low.

I have a Li-ion charger, so that would not be a problem.
45/70 was right about my intended us - as a cheaper replacement for L91s. So like L91s, I want to use them as backup batteries, able to hold their charge for years, working in cold condition, and not prone to leaking.
Of course I have rechargeables in my light as primary energy source, but sooner or later they're out of juice.
And... if I had to use the unprotected 14500 because of all other rechargeables are flat and they showed more than 3.0v after use... then I'd of course recharge them.

do something for the environment. lithium-ion cell is very toxic to the nature

Are L91s any better? And I wouldn't throw them away, I'd recycle them properly.

Just because you only use the cell once doesn't mean you are any better protected from the dangers that a protected cell is designed to prevent.

As far as I see it the protection circuit protects against overcharge (which shouldn't happen in a decent charger), short circuit (which shouldn't happen if stored properly, and hopefully not in a Nitecore light), and overdischarge (which I thought posed only a problem if you tried to recharge those cells again. But correct me if I'm wrong, I've only used protected cells so far)

balou, do you buy your L91's online? Usually you can find them for around $2 a piece here in the US, locally, and close to that, if not cheaper online.

Nope. B&M stores sell them for $5/piece locally (USD:CHF is 1:1 again at the moment...), cheapest swiss online store sells them for $2.30 a piece plus $6 s&h. Cheapest international offer I saw is on 4sevens, $22 for 8 pieces, $0 s&h. Any other sources?

 

[45/70]

I'm beginning to see where you might have a problem buying online, balou. I checked Thomas Distributing and they have L91's for US $7.87. The problem is, shipping to Switzerland is US $37.55! If you live here in the States, sometimes with Thomas you can purchase some other trivial, but useful items and reduce the shipping costs a bit. I doubt if that would help however, in your case.

The only thing I can think of is if maybe you bought a larger quantity from the Swiss online dealer you mentioned, maybe the shipping would work out to be cheaper?

I hate to say this, the last L91's I bought a month or so ago, I paid US $7.97 + 6.5% tax for a 4 pack, and then sent in an Energizer $5 rebate coupon. That probably wouldn't have worked for you in Switzerland though.

Hopefully you can find a way to get a better deal on L91's. I would still pursue that, rather than using 14500's as disposables.

Dave

 

[Pummy]

how about the 4sevens Polish site?

4 Panasonic cells for 10 euros?

 

[Th232]

As far as I see it the protection circuit protects against overcharge (which shouldn't happen in a decent charger), short circuit (which shouldn't happen if stored properly, and hopefully not in a Nitecore light), and overdischarge (which I thought posed only a problem if you tried to recharge those cells again. But correct me if I'm wrong, I've only used protected cells so far)

On this point, if there is no protection circuit, the light will quite happily keep draining the battery until something else gives way, maybe you might just reduce its capacity, but it might also do all the usual nasty things, venting with flame &c.

 

[45/70]

On this point, if there is no protection circuit, the light will quite happily keep draining the battery until something else gives way, maybe you might just reduce its capacity, but it might also do all the usual nasty things, venting with flame &c.

I don't believe you can get a healthy LiCo Li-Ion cell to "vent with flame" while discharging. This only happens when a cell is charged that has been overly discharged, or is in otherwise poor health/been abused, or charged/discharged at a phenomenally high rate.

Dave

 

[csshih]

indeed. I have never heard of a case where you can get a cell to vent while discharging -- unless you start reverse charging it.

 

[45/70]

-- unless you start reverse charging it.

Mmm, I'd say that would qualify as having been abused.

Dave

 

[balou]

The only thing I can think of is if maybe you bought a larger quantity from the Swiss online dealer you mentioned, maybe the shipping would work out to be cheaper?

No, shipping only gets more expensive if they cannot pack it in a padded envelope any more

how about the 4sevens Polish site?

4 Panasonic cells for 10 euros?

Those are CR123s - it's cheaper if I order them from 4sevens US


Will continue this post tomorrow - tired. Waiting in the ER for 3h, getting an arterial puncture and IV drip for nothing at all on a friday night is very funny :shakehead

 

[Th232]

I don't believe you can get a healthy LiCo Li-Ion cell to "vent with flame" while discharging. This only happens when a cell is charged that has been overly discharged, or is in otherwise poor health/been abused, or charged/discharged at a phenomenally high rate.

Dave

indeed. I have never heard of a case where you can get a cell to vent while discharging -- unless you start reverse charging it.

Funny, I was always under the impression that they would. So does overdischarging just reduce the capacity of the battery, or does something else also happen?

 

[balou]

Funny, I was always under the impression that they would. So does overdischarging just reduce the capacity of the battery, or does something else also happen?

I've opened two laptop batteries, both of them had 18650 cells which were about 2-2.4 (and better cells - bad balancing). That's why I wondered:
1. could it really pose such a risk?
2. how much energy is still stored in them below 3v?

I hope that you guys can answer 1, and then I guess I'll buy two cheap unprotected, and find out number 2
edit: well, only if I know they're not gonna explode of course

 

[mfm]

Edit: answered something else than was asked

 

[Th232]

Looks like that link refers to overcharging, and not over discharging. Or am I missing something again?