LI-ION protected or unprotected?

[alx]

I think i almost decided which one to buy. Let me explay why will probably be sku.12594.

1. should be an all in one charger.

2. because now, 10440 cells are ONLY UNPROTECTED, the charger should be "protected". And this is not enough. Charger should be limited to max 4.2V and 200-220mA. I read more reviews about wf-139, and even is protected, it will overcharge batteries up to 4.25-4.3V or more (shorting their life). So we have double cons here against Ultrafire charger (not so slower as required and voltage overcharge).

As i said, charger should be slower (charge ONLY 200-220maH), so ... what remain: sku.4151 and sku.12594 (black version of sku.4151, tr-001). But what about overcharge about this model. I don't know because i ca't find reviews about it, but i know is newer then his "white" brother (sku.4151) which has a lot of reviews. It seems that overcharge problem persist here too, but can be fixed using 2 Zener diodes (which are missing from factory). I will order sku.12594, open it and see if is the same as sku.4151 and diodes are missing here too. If yes, see the fix here (in german):
http://www.messerforum.net/showthread.php?t=51750

Use google translator to translate it in english:
http://translate.google.com/transla...esult&prev=/search?q=tr-001+wf-139&hl=en&sa=G

again... is anybody here already owning sku.12594 charger and can make some test/measurements till i receive one?

regards,
alx

 

[LarryDFW]

kkt;

I've built hundreds of Cree lights using #18650 lithium batteries.

They are quality cells (LG, Sanyo or Panasonic), but do not have the "chinese" protection circuit boards.

IMO. they are safe to use. Here is one BluRay model I built using two #18650, for long operating times:

http://www.laserpointerforums.com/forums/YaBB.pl?num=1231740101/2#2

I would not worry about low voltage at all. High voltage is more of a concern.

Some of the 18650 or 123 Chinese cells are MUCH more likely to be problematic.

Larry DFW

 

[Gazoo]

Low voltage can damage a cell and it can vent while charging. So low voltage is a concern.

 

[Gazoo]

I found http://www.batteryjunction.com/li18322mahre.html

Protected cell 3.6v and 2600 mA. I d'ont know how those protection circuits will hold up with multiple batteries though. You may need to build your own protection for a two cell pak.

Running these in series will be fine. However when it comes to lion batteries don't skimp if possible.. ;D I have bought my batteries from AW over on CPF. Sure they cost more, but they are well protected and of much higher quality.

http://www.cpfmarketplace.com/mp/showthread.php?t=187951

 

[alx]

Hi gazoo,

the problem now is the charger, because 10440 cells are available in the market only unprotected. for the rest of models, i ordered only protected cells. now I need a charger to be used to charge all Lithium models. doesn't matter time to much, important is to be all in one charger (anyway, is better to be slower, to protect better the cells).

alx

 

[Gazoo]

The problem is not whether or not the batteries are protected. It is with the charging current and I think that's what you mean. I have been thinking about this and really the cheapest solution is to have a charger dedicated to the 10440 cells, and another charger that will charge everything else. I can think of other possible solutions, using a hobby charger for example. But it would require battery holders which are difficult to come by for the non standard size lions.

There probably are solutions I don't know about and maybe someone else can chime in here.

 

[alx]

hi gazoo,

we will see.... after sku.12594 will arrive. it will take more then 3-4 weeks...

Question: "protected battery" = prevent overcharge/discharge battery more/less then 4.2v/2.7V?

alx

 

[Benm]

Question: "protected battery" = prevent overcharge/discharge battery more/less then 4.2v/2.7V?

It depends. Protection circuits always protect from discharging under 2.7 or whatever the safe limit for the cell is, and usually also against short circuit or overload.

Some will also open circuit if overcharged or even when charging too fast, but i'm not sure you should rely on the built in protection board for that.

If you want to protect a 10440 application from emptying the batteries too far, it IS possible to take the protection circuit from another size battery (CR123 for example) and connect that in the appliance. This can be cheaper then getting just a protection circuit.

 

[alx]

good hint... i will think about ;-)

regards,
alx