problem with my new charger?

lightheart

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..i just got a new tenergy tl-100 & 4 new protected tenergy 2200ma 18650's ..the batteries had about 3.6 volts on them when they arrived..i put 2 in the charger..the light on the charger was red indicating charging..i monitored the voltage while it charged thinking light would go green and stop at 4.2 but it kept going higher..when it hit 4.27 i stopped it...did i pull the plug too soon..i thought this charger would cut off at 4.2..should i try agin and let it go further?..another odd thing i noticed is that when the batteries were at 4.25 if i pulled the plug and put it back in they continued to charge more..however if i removed the batteries from the charger while it was still plugged in and then reinserted the batteries the light turned green like they were fully charged?..the light never went green on its own though while they were charging from 3.5 up to 4.27..
 

VidPro

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if the charger is going to high, but you have ELECTRONIC added protected cells, the protection will disconnect the battery from the charge.
so your reasonably safe cause you were smart enough to have protected.

When the protection disconnects the battery, the voltage you (could be) reading with everything still connected and in place, could be the open voltage of the charger.

you Can charge to about 4.35v without destroying a good cell, but it is not good for it, so so far you have not damaged the cell.

protection can be set for 4.20 +- .05 OR it can be set for 4.35v as a last chance emergency type of shutdown. Newer sold things usually do not use the higher voltage on the protection, some older stuff had used this method before. so the protection might have cut the connection, i donno, you could determine that. some smaller electronics with li-po still charge to a 4.30 +-5.

the cheap li-ion chargers will usually charge to a maximum voltage, putting the cell back on does not not "restart a sequence of charging" usually, it just keeps charging till it reaches the voltage high again. if the voltage high is to high, then . . . Ohhh i know check the specs for the charger, see if the spec sheet thinks that is normal
there WERE li-ion chargers sold that RELY highly on the cell itself going into the charger being a protected cell, they were only sold FOR protected cells, and would be bad for unprotected cells, that Method isnt concidered proper, but it does work.


Check the voltage of the cell itself. attempt to determine if the cells own protection disconnected the cell.
it is great that you are aware of what happened, ummm dont know what to tell you, but as long as the cell is protected, your not in huge dangers.

also, i would note that one time i got a free voltmeter from an electronics supply place, it was VERY accurate, but when the battery in the voltmeter was low, the readings on the meter were high. so the readings i got one time freaked me out, untill i threw out the cheap meter :)


should i try agin and let it go further?..
i would, but i am a nutcase , and i would do it where i could control all aspects of the situation, and only to achieve final readings and determine every aspect of the situation. and i would do it in the garage , with it in the bottom of a metal can. also knowing that you dont charge li-ions in the COLD.
i think some people would send it back, some people will think they can manually stop it everytime (good luck), and some people would ask an expert and have them determine what to do.
sooo
wait till an expert comes along , cause it aint me. :)
 
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lightheart

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thanks vidpro..i am using a fluke 87 with new battery so i know voltages are correct...the tenergy charger says it will shut off when cell is charged so it should work on protected or unprotected cells...if the battery protection circuit kicks in does it then damage the cell or does it reset after some time?..i read that charging to 4.3 versus 4.2 could mean the difference between 100 or a thousand cycles before cell is no good...i just popped in my other 2 18650's..they were at about 3.5 also...light is red...will watch carefully
 

VidPro

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if the battery protection circuit kicks in does it then damage the cell or does it reset after some time?..

as you already know the higher you charge it, the more likly when its aged and gassed up it will fail, reduced cycles.

the electronic battery protection will trigger and re-trigger millions of times , at the voltage it triggers at, and when you go to discharge the cell, unless a fluke occurs it will reset, and discharge just fine everytime.

oh and when you high charge it and that gets less cycles, and it get bad, that battery then is dangerous, as aged, self discharging, low capacity, and all that that doesnt make "cycles" is the same thing that makes it dangerous and heat up on charge. so things that make it bad, like to low discharge, to high charge, to fast charge or discharge, will eventually make it more dangerous too.
 
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