What ? your circuit is passive, a battery is active...cycborg wrote:OK, suppose you're an electronics hobbyist and you dial this supply down to 5 V to power a circuit on your breadboard. Do you think this supply would refuse to provide any power unless your circuit was pulling current at the current limit?alexis57 wrote:doesn't provide any current anymore when the voltage battery reached the power supply voltage
It's basic electricity knowledge... I don't understand what you tried to explain me... But if you use a power supply like the one for your computer, which you cannot choose the current, then yes, the battery will be charge with the maximum current. If no protection inside the power supply, it can fried.
Yes, it does automatically... that's why we call it "a charger" and not a "simple power supply".A charger (or smart charger, in dnmun's parlance) will do this automatically. A power supply will do it through the intervention of an attentive operator.
The exact term will be : "charger" = "smart power supply", a smart-charger doesn't exist since it is... by the definition of a charger.
A power supply is silly, he just adjusts what you want. You want a current of 1A for the current source behavior? it'll provide 1A, you want 5V? it'll provide 5V.
Actually, I don't care, you can use it, but don't tell it works for getting full charge and don't tell it's fitted for a Lithium battery.
Could you take a video with this way ? I really want to look at this.Russell wrote:You CAN charge a Li-ion battery fully with a power supply but it's best to use one with a current limiting feature. Say you're charging a single cell, just set the power supply to 4.20V and the current limit to an appropriate value and go. The power supply will maintain a CC for a period of time, depends on battery state of charge and current limit, then the current will slowly decrease over time as the voltage increases. At 4.20V the current will be zero and the battery will be fully charged. This method is slower than a dedicated Li-ion charger but it still works just fine, that's one of the nice things about Li-ion batteries.
If the current is decreasing when the voltage is increasing, your power supply is REALLY BAD.
Since it should work in "current source" and if it provides another current than the one you chose... You just proved that it's not possible with a power supply...
The only thing possible is when the battery reachs maybe 4.1x V, the power supply goes into "voltage source" and then the current will decrease but just because of the internal resistance (differential voltage and internal resistance..)
As I said, this way of charge is not for a fully charge...
From your eyes it's maybe a CV shape but it's not.
AGAIN : if you charge with a power supply, you can charge only with the CC shape. You couldn't fully charge since you couldn't use the CV shape. (this one requires a complicated circuit) The cut-off for a small current at the end of the charge is only for CV shape. Then it cannot exist with a simple power supply.
A Lithium charger is not really more expensive and it's faster for getting a full charge. Why trying to find a really small cheaper way for a worser result ?
Thank you =)