Li-ion Speak ,
Just some thoughts on Li-ion batteries .
- There are good cells , bad cells , and average cells , and one should try and buy decent cells .
- Depending on what type of cell your after , you may either be spoiled for choice or very limited in what you can buy .
- When deciding on what light to buy , you really need to consider the battery first , and associated costs and possible problems
- 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 .
- 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 .
- 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 !
- 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 .
- 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 .
- 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 .
- 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 .
- 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 .
- 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 .
- 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 .
- 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 ….