Li-ion Speak ! Perhaps you should read this ? [ Maybe ]

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old4570
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Li-ion Speak ! Perhaps you should read this ? [ Maybe ]

Li-ion Speak ,

 

Just some thoughts on Li-ion batteries .

 

  1. There are good cells , bad cells , and average cells , and one should try and buy decent cells . 
  2. Depending on what type of cell your after , you may either be spoiled for choice or very limited in what you can buy .
  3. When deciding on what light to buy , you really need to consider the battery first , and associated costs and possible problems
  4.  Please realize Li-ion has inherent dangers , and if your not prepared to be careful , perhaps you should stick to AA or AAA flashlights , and believe me , they have come a long way .
  5.  So you have decided on a battery of choice , next you will need a charger , and aren’t there a few of those . Choosing a charger is not nearly as critical as the battery choice , but you do want to chose wisely . Cheaper chargers that don’t terminate charging on completion [ continue to trickle charge ] , need to be monitored , and if your to lazy to do so , find one that terminates [ stops charging ] on completion .
  6. You have chosen 16340 / 18650 , and you are spoiled for choice . There are several paths you can take , the first being the tried and true , AW cells . The Americans swear by them , and depending on variables push these cells hard on new comers . Now to be fair , the AW cells have had issues from time to time as any battery would , there not 100% foolproof .  The second path to try is  a different battery  , but still high quality . And the third path being the cheaper brands , which is where we start to find problems . Research and more research is needed in these murky waters , I find it funny that some reviews highly recommend a battery as the best ever , etc , and the person actually puts in that these are the first such batteries they have tried ??? So the problem is , some one who may be lacking experience or knowledge is highly recommending something they may know very little or nothing about . And there test procedure is to throw the new batteries in a new light , be amazed its better than a Maglite , and then proclaim them the best ever ! 
  7. So when researching , please try to bear in mind that the review may be highly questionable . or simply nothing more than opinion based on more opinion .
  8. Li-ion Care :  Now li-ions need monitoring , to see what sort of condition they are in , and for this you need a Multi Meter . You don’t need a expensive one , but you need one , otherwise it’s a little like driving a car with your eyes shut .
  9. Charging Li-ion :  Ok this is once more very personal , some don’t like charging the cells fully [ 4.2v ] and other threat about over charging . Now this is highly variable , and requires a article of its own ..  If your charger charges to 4.15v or anywhere to 4.21v , you should not worry too much . If your stressing about over charging ??  Then you will need to find a charger that charges to 4.2 or just under .
  10. Over discharging , now here is something you should try to avoid , Li-ion has no memory effect , but deep discharge does affect the cell structure of the material carrying the charge in the battery .  And if you disrupt/affect it too much the battery will degrade faster .  Most Li-ion cells start to drop output significantly at around 3.5v , so if you can recharge the battery before you get to 3.5v , you will be helping to put of cell degradation .
  11.  Battery quality :  Not all batteries are equal , they simply cant be , manufacturing simply is not that advanced .  Depending on your charger !  you may find some cells stop charging earlier or latter than others , and this can be attributed to cell quality [ if you have a solid charger ]  Now cells that stop early may do so because , as the cell comes close to being fully charged , resistance to further charging increases , the worse the cell , the earlier this resistance kicks in , and this may cause early termination in charging [ again dependent on individual charger ] The other thing you may find is that some cells go higher , and rather than stopping at 4.2v actually over charge , again this could be as simple as the cell being much better than others and the internal resistance to charging does not kick in until latter , thus causing a overcharge [ again dependent on individual charger ] Now its hard to say with only one charger , but should you be in a position of owning 6 or more chargers , you may over time notice a trend in some batteries charged with different chargers .
  12.  Testing Cell Quality :  Now it’s a good idea to have some idea of your batteries condition . [ You need a MM ] . Charge the batteries , and as soon as they come of the charger , measure voltage .. For arguments sake lets say you charger always completes at 4.2v .  You charged 2 cells , both came of at 4.2v , check again one hour later , [ for arguments sake ] lets say one is still 4.2v and the other is down to 4.15v . We can very simply determine from this that the battery at 4.2v is the better battery [ both batteries being otherwise the same ] . And lets say a week latter the good battery is at 4.19v and the not so good one has sagged to 4.05v . Now it does not mean you have to toss the not so great battery , but it helps to be AWARE of its less than staler performance .
  13.  Multi cell use :  This is where most people run afoul of Li-ion batteries , they have no idea of what is required .  Simply you need to match the cells , condition , capacity , discharge . And to determine these things you need to test the batteries . Once you have 2 matched cells , you then need to monitor [ MM ] the cells to see how they behave in the flashlight . The battery closest to the head may run hotter than the cell at the back of the light , with Li-ion , temp affects discharge . The warmer the light and the battery , the higher the discharge . So what happens is , a imbalance may occur simply from using the light , so you need to monitor the batteries to make sure you are aware if this occurs , there by maybe allowing you to swap the cells around to balance out the discharge .
  14. Cells degrade whether you use them or not , some claim 10% a year , if anything cheaper cells may degrade even faster , maybe as bad as 25% a year , maybe more . All I know is I had some 2 year old 16340’s at around 50% capacity , so more reason to keep an eye on your cells .

 

Im sure I haven’t covered everything , but that was not the idea , the idea was to get you the reader thinking about what you are doing , and to be aware of the fact that you are possibly playing with fire , and if you have done nothing to monitor you batteries , perhaps its time to do so .  

 Always remember , the easiest thing in the world to do , is to expel hot air from your lungs and through some vocal chords ..
The resulting sound may , or may not be worth listening too ….

 

srfreddy
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What? Standby charge? I should hope not! 

okwchin
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Standby charge is necessary, and nothing wrong with that. Its to keep the battery topped up while it can. Consumers dont want to pull their laptop off the charger only to find it has self discharged down to 50% as your heading out the door to your 3 hour mobile presentation.

Unfortunately that reduces battery life a little, storing them at high charge levels, but its a functional thing for consumer products

"like everyone else - I’m looking for my next “last” flashlight" -  ohnonothimagain

srfreddy
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Li-ions have-almost undetectable self-discharge. 

photon1k
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I think this is a subject that warrants regular emphasis. I would encourage anyone who read the OP and wasn't already familiar will all of the ideas touched upon to do some further reading. Google any ideas or concepts that were unfamiliar and get yourself up to speed. You owe it to yourself, and it may help ensure your continued enjoyment of this hobby. I have spent hours reading about the proper use and care of lithium based rechargables and I still learned something new from old4570's post.

sixfink
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I have encountered one case of a bad Li-Ion rec and walked away just because I was lucky. In the meantime, I did a LOT of reading, not only BLF, but also old CPF posts, other message board posts, US Army PDF bulletins, and manufacturer's bulletins.

Old4570 sums it up real good! Smile

 

 

...buy quality. Then check, check, double-check. Easy as that.

And never forget - there still may be a certain risk. If you're fine with that and ready to act accordingly, you're set.

 

I will stick to my CR123A lights - but, to be honest, I will now treat those lithium cells with MUCH more respect than an alkaline. We only have two eyes, two hands, two lungs - and one life. I estimate driving my '67 Mercury a much greater risk, with mere lap belts, no air bags, no safety crash cell, no safety fuel tank, no airbags, no crumple zone, no headrests, no assist brakes. Then again, my Mercury has developed a rod knock this very tuesday; and won't be driven much until I have a new (and pricey!) shortblock ready. So that; in turn, makes my lithium-powered lights my greatest danger right now. Ack!

kragmutt
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sixfink wrote:

I have encountered one case of a bad Li-Ion rec and walked away just because I was lucky. In the meantime, I did a LOT of reading, not only BLF, but also old CPF posts, other message board posts, US Army PDF bulletins, and manufacturer's bulletins.

Old4570 sums it up real good! Smile

 

 

...buy quality. Then check, check, double-check. Easy as that.

And never forget - there still may be a certain risk. If you're fine with that and ready to act accordingly, you're set.

 

I will stick to my CR123A lights - but, to be honest, I will now treat those lithium cells with MUCH more respect than an alkaline. We only have two eyes, two hands, two lungs - and one life. I estimate driving my '67 Mercury a much greater risk, with mere lap belts, no air bags, no safety crash cell, no safety fuel tank, no airbags, no crumple zone, no headrests, no assist brakes. Then again, my Mercury has developed a rod knock this very tuesday; and won't be driven much until I have a new (and pricey!) shortblock ready. So that; in turn, makes my lithium-powered lights my greatest danger right now. Ack!

sixfink likes to live dangerously =O

richadsc
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Now it’s a good idea to have some idea of your batteries condition . [ You need a MM ] . Charge the batteries , and as soon as they come of the charger , measure voltage .. For arguments sake lets say you charger always completes at 4.2v .  You charged 2 cells , both came of at 4.2v , check again one hour later , [ for arguments sake ] lets say one is still 4.2v and the other is down to 4.15v . We can very simply determine from this that the Laptop Battery is the better battery [ both batteries being otherwise the same ] . And lets say a week latter the good battery is at 4.19v and the not so good one has sagged to 4.05v . Now it does not mean you have to toss the not so great battery , but it helps to be AWARE of its less than staler performance .I agree with that.

2100
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The weaker battery can be used to drive less demanding apps, like 100mW 405/532nm lasers.