usb players in market on mobile battery

[Audioguru]

hmm i see ya okk ll do that , but with how much voltage level ? i mean 3.7 volts battery or 5 volts power supply?

You said you wanted to power it with a Lithium battery, not a 5V power supply.

volt x amp. Vmax or Vmin. for the circuit ?

V x A= POWER but you need to know the current, not the power. The average voltage of a Lithium battery is 3.7V so power the MP3 player with 3.7V then measure the current.

 

[rajaram04]

You said you wanted to power it with a Lithium battery, not a 5V power supply.


V x A= POWER but you need to know the current, not the power. The average voltage of a Lithium battery is 3.7V so power the MP3 player with 3.7V then measure the current.

ya actually i thought i ve to make experiments with some other sources to make sure about unknown parameters but okk i got that i ll proceed as per that

- - - Updated - - -

ya actually i thought i ve to make experiments with some other sources to make sure about unknown parameters but okk i got that i ll proceed as per that

well any precautions while measuring current ???? please suggest

 

[Audioguru]

A current meter is almost the same as a piece of wire. No precautions.

 

[rajaram04]

A current meter is almost the same as a piece of wire. No precautions.

hmm i picked a battery for experiment purpose & its showing 3.85 volts with 59.2 mA as per your advice

the mAh of this battery is unknown but this one is Li-ion 3.7 volts MG-4C . . .

 

[Audioguru]

A Lithium battery cell is 3.2V when its load should be disconnected, 3.7V average when almost dead and 4.2V when fully charged. Your battery was almost dead.

 

[rajaram04]

A Lithium battery cell is 3.2V when its load should be disconnected, 3.7V average when almost dead and 4.2V when fully charged. Your battery was almost dead.

ye right it is dead i ve to bring new one

 

[Audioguru]

Did you charge your battery to 4.20V then leave it charging until the charging current drops low?

Can you buy a battery that is name-brand (not a fake and not a cheap copy) and is new (not one or two years old)?