"Most Li-ions are charged to 4.20V/cell and every reduction of 0.10V/cell is said to double cycle life. For example, a lithium-ion cell charged to 4.20V/cell typically delivers 300–500 cycles. If charged to only 4.10V/cell, the life can be prolonged to 600–1,000 cycles; 4.00V/cell should deliver 1,200–2,000 and 3.90V/cell 2,400–4,000 cycles. Table 4 summarizes these results. The values are estimate and depend on the type of li-ion-ion battery." (emphasis mine)
* you are completely ignoring the amount the battery is being discharged, just as important, if not more so, to cycle life..if you charge it to 3.7 and never use it, will it last forever? Besides when they say "300-500" cycles theyre talking about discharge to 2.5 or 2.6, way below where amy one goes with the Cera.. its silly..
Pretty clear to me, 1,200-2,000 cycles (from 4.0 charges) is four times the 300-500 from 4.2 charges. This insight is not confined here, I've also cited (and shown reference for) the military practice of limiting charge voltage to vastly extend battery life.
Yeah so? But you are cutting down drastically on the duration of the battery in the Cera! Youre done at 3.4 so at 4. volts charge, you have .6 volts to vaporize with, each .10 volt is over 15% of your operaring time ...! Yeah if you dont use the battery as much itll last longer. duh.
tedthehed said: ↑
If your batteries are dying prematurely I suggest you take your dmm's and put the pins in series with your charging battery when its
at the end of its charge cycle , and make sure it isnt going above 4.2 volts...it shouldnt be getting more than slightly warm either.
This also is not correct IMO. Current readings are taken in series, not parallel. Voltage readings are always taken in parallel with the source. The Voltage reading your suggest should always equal zero. That is when the end of charge is reached the battery voltage exactly matches the charger set voltage (the whole basis of Constant Voltage charge routines.
**Im not going to get involved with this one. Obviously the idea is to get the voltage while under charge, I think people understand that.
Your explanation is more of a confusation..while under charge a series reading will give you a forward voltage, as it is called, taken by placing probes , in series, between the positive end of the battery and the positive charge terminal of the charger...you should get a reading of at least a volt, or two, while under charge.
I really dont understand what you mean by parallel with the source , unless you mean to say "touch each end of the battery"???
Not to mention that the owner really has no way to make this series measurement (calls for opening the unit, disconnecting the battery and either dis assembly of the connector or other modifications of the hardware in addition to meter skills past most casual owners).
**no, it doesnt. see forward voltage, above. try to not get hysterical about this.
Nor is there a need for most, the 'battery level meter' tells all that needs to be know for those who care.
**yes youre right except for the fact Im discussing a possibly malfunctioning charge unit , so the voltage reading may be off in the first place. The reason for my suggestion.
BTW I just made a measurement of the voltage in an empty 18650 battery bay of my intellicharger 4 ( a series measurement, btw) and got 5.25 - 5.30 volts,
I guessing thats normal, and yours should be around that voltage also.
as for cleaning the Cera cart, can you guys get a hold of 99% isopropyl alcohol?
the difference between 99% and the regular 70% is like night and day!!!
if you never used 99% go get some now, I get it at the local Voms supermarket, $1.75 for 16 ozs.
I just dont see any thing sticking after a soak and shake in that stuff! especially an overnight soak!
tell me it this doesnt work! try find a medicine bottle that the cart will slide in, add the alcohol, and shake it about in there,
slosh the alcohol around good. itll clean it.
