Battery help needed. Use what I have, or buy new 18650's?

[MstrHnky]

here's the combo i currently have:
http://www.dealextreme.com/details.dx/sku.6979
http://www.dealextreme.com/details.dx/sku.936

i know it's a cheap combo, but i was planning on using them in a WF-600 that is now back ordered and i've since been refunded for the light.

i will be purchasing a dereelight dbs and just need to figure out what batteries to use.

it says the batteries are protected, but that has been up for discussion. the charger has overcharge protection on it, but if the batteries don't have protection, they can over-discharge while in use and ruin my future DBS, something i'm not willing to leave up to chance.

i know everyone loves AW's batteries, but at $12 a piece, i am hoping to find something reliable at a lower price.

http://batteryjunction.com/2600pcb-18650.html
i saw these at battery junction. they have protection and are a $4 cheaper than AW.

so what should i do?
1. use my current batteries/charger
2. order the above batteries from battery junction/use current charger
3. order AW batteries/use current charger
4. none of the above (provide a link to your option)

the charger is slow, i know, and it only has one channel current, so i plan on charging only one battery at a time (i will only have a need for one 18650 in the DBS anyway). since it has protection and i haven't read any terrible reviews, i think i'll stick with it.

i don't want to spend $$$. i'm only going to buy one or two batteries if necessary, and won't buy a charger for more than $20, if possible.

 

[dulridge]

Go with what you've got till the cells and/or charger fail, then buy AW cells and another DSD or a better charger for your purposes. You can easily spend a LOT on batteries and chargers - make sure you know how and why you want to before you drop a pile of money.

Those are protected cells (Well mine are anyway) - they shouldn't over discharge.

 

[MstrHnky]

since i never got the flashlight that i ordered these for, i never charged them.

i just grabbed them from my room and they state:

"warning:
the voltage of full charge and cut-off discharge is 4.2V and 2.75V"

so i guess this means that they are indeed protected. nice.

if 2 batteries have different voltages remaining, will they not safely arrive at a full charge evenly? i thought i would be able to charge one at a time, but the dx forum states that it might be better charging both at once to reach full capacity.
http://www.dealextreme.com/forums/Default.dx/sku.936~threadid.9507

if one battery is fully charged, will the current then pass on to the other battery that is drained without overheating?

 

[dulridge]

since i never got the flashlight that i ordered these for, i never charged them.

i just grabbed them from my room and they state:

"warning:
the voltage of full charge and cut-off discharge is 4.2V and 2.75V"

so i guess this means that they are indeed protected. nice.

if 2 batteries have different voltages remaining, will they not safely arrive at a full charge evenly? i thought i would be able to charge one at a time, but the dx forum states that it might be better charging both at once to reach full capacity.
http://www.dealextreme.com/forums/Default.dx/sku.936~threadid.9507

if one battery is fully charged, will the current then pass on to the other battery that is drained without overheating?

Since they're charging in parallel, I'd there should be no big issue. You can charge the cells one at a time - and they will charge faster as they get all of the current.

Think of a water pressure analogy - you are putting a certain amount of pressure (voltage) into the cells - the one with a higher voltage (pressure) will get less charge (water) then the lower pressure one given that the input pressure (Around 4.2V) is constant.

Doubtless someone who knows a lot more than me will be along shortly.

 

[MstrHnky]

thanks for your input. chances are, i will do an initial charge with both in the unit and go one at a time from there. i only have the need for one battery at a time currently.

what is the shelf life of these batteries once they are charged? the battery that's not in use will just sit on a shelf until the first one goes out. i suppose i could give it a quick charge just to "top it off" before putting it in the light.

 

[dulridge]

thanks for your input. chances are, i will do an initial charge with both in the unit and go one at a time from there. i only have the need for one battery at a time currently.

what is the shelf life of these batteries once they are charged? the battery that's not in use will just sit on a shelf until the first one goes out. i suppose i could give it a quick charge just to "top it off" before putting it in the light.

They will live for about three years - after that they are unlikely to work at all. As for charge retention, do a quick check on the voltage. If it is over 4.1V, most of the charge is still in it. I'd not bother charging them unless the voltage is below 4V though obviously runtime will be less. Somewhere recent in the batteries subforum you will find a chart of voltage versus %charge for LiIon cells. Do not ever let them get above 4.2V or life will be shortened and above 4.3V kaboom is a possibility. One of mine that was last charged (to 4.2V) over a month ago reads 4.18V (about 98% charge) just now.

 

[MstrHnky]

They will live for about three years - after that they are unlikely to work at all. As for charge retention, do a quick check on the voltage. If it is over 4.1V, most of the charge is still in it. I'd not bother charging them unless the voltage is below 4V though obviously runtime will be less. Somewhere recent in the batteries subforum you will find a chart of voltage versus %charge for LiIon cells. Do not ever let them get above 4.2V or life will be shortened and above 4.3V kaboom is a possibility. One of mine that was last charged (to 4.2V) over a month ago reads 4.18V (about 98% charge) just now.

i don't have a way to tell the voltage (no meter) but the battery is protected at 4.2V and the charger has an auto-off feature.

i have no option at this point but to trust the two of them. :green:

 

[dulridge]

i don't have a way to tell the voltage (no meter) but the battery is protected at 4.2V and the charger has an auto-off feature.

i have no option at this point but to trust the two of them. :green:

A cheap meter will be fine for this - should only cost you about $5. Meanwhile, as long as you pull them out of the charger when the light goes green you will be fine.

The protection circuit ought to prevent overcharge so it shouldn't be too big a deal but I'd never charge lithium ion cells unattended, just in case. Relying on last ditch protection long-term is a poor idea.

Get a cheap digital meter when you can; but meanwhile keep an eye on the charger when it is charging.

 

[MstrHnky]

A cheap meter will be fine for this - should only cost you about $5. Meanwhile, as long as you pull them out of the charger when the light goes green you will be fine.

The protection circuit ought to prevent overcharge so it shouldn't be too big a deal but I'd never charge lithium ion cells unattended, just in case. Relying on last ditch protection long-term is a poor idea.

Get a cheap digital meter when you can; but meanwhile keep an eye on the charger when it is charging.

whoa, i think i just avoided a really bad accident. when i took the batteries out of the charger to read the label for my last post, i may have put one back in upside down (not sure). i never once plugged the charger into an outlet, i just put them in the unit and layed it down on my chair. i went to put it away just now and it was very warm to the touch! there was also an odor coming from the batteries.

i'm assuming they both had a partial charge from the factory and while they were just sitting in the unit, the reverse polarity was causing a problem.

i also noticed that the blue wrapper was coming up from the bottom of the battery... i didn't notice this before.

needless to say, i quickly took them out of the charging unit and put them outside to cool down.

i don't know the specific cause for this, but can only guess one was placed with the + end of the battery in the - end of the charger. in any case, i wonder if these batteries are now any good? i have no uses for an 18650 to test them out until i decide on the dbs i want.

 

[dulridge]

If you leave unprotected cells in the DSD charger unplugged, it will kill them. I speak from experience.

NEVER try to charge an unprotected lithium ion cell discharged below 2.5V unless you enjoy fires with toxic smoke.

Protected cells ought to be OK as they won't go below the protection level and will register 0V until they are reset in a charger. If the cell heats up quickly, toss it and buy some AW cells. But as ever, NEVER charge lithium ion cells unattended.

 

[MstrHnky]

If you leave unprotected cells in the DSD charger unplugged, it will kill them. I speak from experience.

NEVER try to charge an unprotected lithium ion cell discharged below 2.5V unless you enjoy fires with toxic smoke.

Protected cells ought to be OK as they won't go below the protection level and will register 0V until they are reset in a charger. If the cell heats up quickly, toss it and buy some AW cells. But as ever, NEVER charge lithium ion cells unattended.

well, these are protected, and did get pretty warm. i have no idea if they're still any good. they cooled down quickly, and are fine now.

i will remember to never keep them in the charger, even unplugged, like i just had them.

what sucks is that i will have to wait until i order my dbs, which won't be before february 12th, then a few weeks for shipment. if the batteries are no good, it'll be another week or two to receive them. d'oh!

at least they didn't catch on fire...

 

[Lighthouse one]

Mstr.... You can't hurt your flashlight by accidentally running batteries too low ( below 2.75 ). With protected batteries, the light will just shut off suddenly at low voltage...nothing gets hurt. With unprotected- the light will get dimmer, but it isn't that quick and rarely will kill a battery. I have lots of each- of course the AW batteries are the best, but lots of members use cheaper ones- and they do fine ( usually)
I also have a dereelight, and I think the light itself may cut out at low voltage... it's also good to use a single battery- say an 18650, instead of 2 smaller ones if the slight decrease in brightness is ok. Lights designed for an 18650 will usually be just as bright as with 2 123a batteries, and in some cases must use only the 18650- as the light circuit will be damaged with 2 123a batteries.

 

[MstrHnky]

I also have a dereelight, and I think the light itself may cut out at low voltage... it's also good to use a single battery- say an 18650, instead of 2 smaller ones if the slight decrease in brightness is ok. Lights designed for an 18650 will usually be just as bright as with 2 123a batteries, and in some cases must use only the 18650- as the light circuit will be damaged with 2 123a batteries.

good to know the dbs might have an "auto-off". the more protection, the better.

i prefer a light that only uses one cell. i'm going to get the 3SD, so my only option is to use one 18650's. from what i've read elsewhere, multi stage lights are usually not as powerful as a digital only option, this was the case with the light i was going to purchase, anyway (wf-600 Q5).

 

[Lobo]

I finally got me some li-ion cells and charger and I am pretty new to this.
But does the protective circuit in the battery prevent the cells from being overcharged in a charger? Cause for me it's very hard to not leave a charging unattended, especially for 6hours which my 18650s requires. And at which point should the charger stop the charge? At exactly 4.2V? Cause my Ultrafire charger seems to lit up green around 4.11V. If you leave it after it turned green, the cells will measure slightly over 4.2V. Is that ok, does li-ion have a slightly higher charge fresh from the charger?

 

[MstrHnky]

I finally got me some li-ion cells and charger and I am pretty new to this.
But does the protective circuit in the battery prevent the cells from being overcharged in a charger? Cause for me it's very hard to not leave a charging unattended, especially for 6hours which my 18650s requires. And at which point should the charger stop the charge? At exactly 4.2V? Cause my Ultrafire charger seems to lit up green around 4.11V. If you leave it after it turned green, the cells will measure slightly over 4.2V. Is that ok, does li-ion have a slightly higher charge fresh from the charger?

hopefully someone else will chime in for you as well, but from what i've read, protected batteries will stop from overcharge and under discharge.
the batteries that i have say they stop at 4.2 and 2.75.

many chargers also protect from overcharging. i would pull them as soon as they turn green. it's such a small difference that it's not worth the risk of leaving them in for the extra .9 volts. definitely don't leave any in the charger unattended, ever.

i don't know a lot about Li-Ions, especially if you've read the rest of this thread , but if you pay attention, you shouldn't have problems.

 

[Lobo]

Thanks, and glad that you're allright. Reverse-polarity seems to be a big no-no, in almost any battery chemistry.

Weird this is that I do use protected cells, and the Trustfire all-in-one-charger is supposed to have auto-cutoff(I think?:thinking. But my cells are slightly over 4.2V if I leave the a bit after the light turned green. And I don't know if I got bad cells, but the annoying low-voltage varning on my Nitecore DI kicks in after about 15minutes on turbo (but not when I run it ever so slightly under turbo) on one of the cells, when it should run well over 1 hour. Time to read up on li-ion for me!

 

[DM51]

MstrHnky, you may have damaged one or both of these cells, or the charger, or possibly the whole lot. It depends on the circuit and how long the cells were on there, but the heat and the small you noticed are not good signs.

Without testing the voltage of the cells, you will not be able to tell if any damage has occurred.

I suggest you acquire a DMM and take voltage readings of the cells, then report back with this information. In the meantime, you should not attempt to use the cells or the charger.

Lobo, Li-Ion cells should never be charged above 4.20V. The protection circuit of a cell can not be relied on to prevent a cheap charger from over-charging and damaging the cell. If your charger is taking 6 hours to charge an 18650, you should get a more suitable one. You should not leave Li-Ion cells charging unattended.

This thread belongs in 'Batteries Included', not here, so I am going to move it.

 

[limecc]

Quote:

I also noticed that the blue wrapper was coming up from the bottom of the battery... i didn't notice this before.

End quote.

At least one of the 'protected' offerings from Trustfire at Dealextreme is only partially protected. I would say that if your battery colouring is blue, then it may be the model I have without undervoltage protection. http://www.dealextreme.com/details.dx/sku.5790 I think the fully protected ones are grey coloured.

 

[MstrHnky]

it's going to be a while before i actually purchase my DBS, i'm waiting on a new pill to become available.

i'll head to lowe's next week and get something to test the batteries. if they are shot, i'll replace them. what sort of readings should i be looking for? i'm not very familiar with voltages, etc.

i'll probably pick up some 18650's from battery junction, assuming their shipping will arrive before anything from DX, and at a cheaper cost than AW.

 

[DM51]

what sort of readings should i be looking for? i'm not very familiar with voltages, etc.

Below 3.5V resting means the cell is over-discharged. Below 3.0V resting, it is badly over-discharged and has been damaged. Below 2.5V resting, it is badly damaged and may or may not be recoverable (with care). Below 2.0V, throw it out.

A "resting" voltage is taken when the cell has been sitting unused and disconnected from anything, including the charger, for ~30 minutes.

The voltage of a Li-Ion cell is a direct indicator of its state of charge, and a DMM is indispensable if you are going to be using them.