Lithium-Ion Batteries and Info

[chipdouglas]

Hello,

I read your informative survey, but I wonder:

1. "Check your Internal Resistance" - How can an average user, who doesn't know much electronics (like me) do that?

2. "Use a protection circuit" - How can I be sure that what is advertised as a protection circuit battery, is realy a protection circuit battery? Take into account that many members here buy batteries from China, and sometimes there can be "mistakes" and the battery will not match the description. Please don't tell me not to buy from China.

3. "If possible, lower the current draw" - And how am I exactly going to do that? I just insert the battery into my laser and fire it. How can I control my laser current draw?

4. "Keep the Temperature low and cool" - OK, so You are telling me not to use my laser on a hot day? Or maybe I should turn on the air conditioning?

5. "Do not dissassemble" - I always wonder how can these things be dissassembled. They are so solid that you need a hammer to break it. And who is insane enough to do it anyway?

6. "Use responsibly" - What does it mean in that regard? You can say "use responsibly" in almost every aspect of your life, starting with your car and ending with your wife...

7. "Keep an eye on them" - Like I do with my children... They also can be wild sometimes...

I am not being sarcastic. I realy wonder.

i am only addressin question 1...

member dr.lava made a tutorial

http://laserpointerforums.com/f67/h...es-how-measure-internal-resistance-57576.html
michael.

 

[Seoul_lasers]

Hello,

I read your informative survey, but I wonder:

1. "Check your Internal Resistance" - How can an average user, who doesn't know much electronics (like me) do that?

2. "Use a protection circuit" - How can I be sure that what is advertised as a protection circuit battery, is realy a protection circuit battery? Take into account that many members here buy batteries from China, and sometimes there can be "mistakes" and the battery will not match the description. Please don't tell me not to buy from China.

3. "If possible, lower the current draw" - And how am I exactly going to do that? I just insert the battery into my laser and fire it. How can I control my laser current draw?

4. "Keep the Temperature low and cool" - OK, so You are telling me not to use my laser on a hot day? Or maybe I should turn on the air conditioning?

5. "Do not dissassemble" - I always wonder how can these things be dissassembled. They are so solid that you need a hammer to break it. And who is insane enough to do it anyway?

6. "Use responsibly" - What does it mean in that regard? You can say "use responsibly" in almost every aspect of your life, starting with your car and ending with your wife...

7. "Keep an eye on them" - Like I do with my children... They also can be wild sometimes...

I am not being sarcastic. I realy wonder.

Some answers to your questions

1) I wouldn't worry too much about internal resistance. You'd know about high resistance generally as it would translate into heat. Li-ion batteries get warm after a few 100 cycles indicating the resistance is going up. The higher internal resistance = closer it is to expended battery/end of life.

2) Cells that are marked protected have the protection cutoff circuit in them. Yes, even some Chinese cells have them too. Quite a few cheaper cells are sold as unprotected cells.
meaning they lack a protection circuit. Rant + aside (Btw) pretty much ALL Li-ion cells are manufactured in Shenzhen or Juhai P.R.C. yes that also goes for Sony, Tenergy, Samsung ... The environmental damage from these battery companies is quite astounding. There is NOTHING green about Li-ion!

3) Current draw. Your laser driver with draw a set amount of current and nothing more. The driver acts as a regulator. You can't really control it other than getting a more efficient driver. example.. I have seen some drivers take 5-6W (2x18650 cells) to produce a nearly 1.5-2W 445nm beam. Other smaller drivers might require 1 cell and draw ~4.5W. It all depends.

4) Keep the temperature of the batteries at around room temperature for optimal performance. IF the battery is
left out in sun and broiling hot, I'd really not try using it, the hotter the cell the more likely something could ignite!! Too cold and you will get decreased output. Done this before.

5) Don't EVER try and take apart a Li-ion cell. Exactly what it sounds like. EXCEEDINGLY DANGEROUS. Some home cookers take these batteries apart as a part of a process for making Methamphetamine. They use the Lithium for generating Hydrogen gas. Quite often the reaction runs away on them causing a huge explosion. Lithium metal is nothing to play around with.

6) & 7) Use with care. Don't let your kids or pets chew on them. Don't send them via airmail without some way of preventing an accidental short. Don't go swimming with them... (OMG how stupid would one have to be to do that/ LOL). Use your common sense. Don't short circuit.... etc

I hope I have answered your questions. I hope none of my answers comes across as rude,
I am giving an example of the kinds of things that might fall into each of your categories.

Hope this helps.

 

[snoutke]

OK, Thanks.

 

[BShanahan14rulz]

just a note... when ever you see the word "primary" on a battery or packaging the batter will NOT be rechargable.


michael.

Yes, THIS!!!:wave:
Also, I'm tired of people saying RCR123a, people find it too easy to confuse with CR123a. Lithium secondaries, imo, should ALL be referred to by their dimensional name to avoid confusion. Nobody thinks a 16340 is a CR123a.

As far as charging goes, proper charging algorithm is to charge at a constant current (whatever it is that is noted on the datasheet, usually around 0.5C, lower for smaller cells, higher for larger cells. Again, datasheet will tell you the safe maximum) until the cell voltage reaches 4.2V. At that point, charge at constant voltage of 4.2V until the current drops off to a negligible level. Of course, if you have a charger, you have no control over the charging algorithm, this is more for the people using stable lab supplies.

 

[bombomlee]

I have a few cells lying around without any casing whatsoever and my country's humidity ranges from 90% in the morning to 100% on rainy days.

Do I have to be worried about this or something?

 

[Isoleucine]

You may need to worry somewhat. If the battery casing isn't tight, the water in the air could seep in... but just be more careful, as batteries tend to function not as well in high moisture environments. Monitor them when they are charging, when they are operating, and so forth. If they get warm at any point, stop using them immediately.

 

[bombomlee]

Ok, got it. Thanks!

You may need to worry somewhat. If the battery casing isn't tight, the water in the air could seep in... but just be more careful, as batteries tend to function not as well in high moisture environments. Monitor them when they are charging, when they are operating, and so forth. If they get warm at any point, stop using them immediately.

 

[BShanahan14rulz]

With the wrapper intact, a cell is hard to short, even if it were loose in a box with a bunch of other cells.

With the wrapper removed, all it takes is a segment of metal as small as a few mm to short the cell out.

Recommend you rewrap the cells, or at the very least, tape the outside so that the sealing crimp (continuous with the case and the - terminal) by the + terminal is completely covered.