# usb players in market on mobile battery

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#### rajaram04

Hello sir
As we observed that normal batteries get discharge in minutes while operating a commonly available cheap china made usb player circuits so we have to apply external power supply via adaptors etc

But ready made usb players with a built in battery is a long time running unit with a single recharge

a 3.6 volts ni-cd battery or a simple mobile phone battery is there to drive the circuit

so how it is possible ? please tell

#### tpetar

Hi RajaRam,

Its simple, cheap China product usually have recycled batteries with drastically smaller capacity then declared.

Ammount of music according to ammount of money. :smile:

#### rajaram04

Hi RajaRam,

Its simple, cheap China product usually have recycled batteries with drastically smaller capacity then declared.

Ammount of music according to ammount of money. :smile:

hehehehe ya sir but when we apply other reputed company batteries there from nokiya samsung etc it also works as same so how thats possible to run the unit on 3.6 volts only & for a long time ?

#### tpetar

hehehehe ya sir but when we apply other reputed company batteries there from nokiya samsung etc it also works as same so how thats possible to run the unit on 3.6 volts only & for a long time ?

How you know that "Nokiya" and Samsung are original? Chinese also write that names.

Original batteries have declared capacities and Chinese usually smaller.

#### rajaram04

How you know that "Nokiya" and Samsung are original? Chinese also write that names.

Original batteries have declared capacities and Chinese usually smaller.

nah nah it is nokia & i prchused original one , i asked for the branded one not china model
They have china material but also but the are dealer of nokia samsung & close family friends too

so i have the original one which is exactly rating 3.6 volts but easily drving out a ready made usb player

#### tpetar

Did you check capacity of battery and power consumption of device ?

What is battery capacity?
What is average current which device use?
What is maximum current which device use?

#### rajaram04

Did you check capacity of battery and power consumption of device ?

What is battery capacity?
What is average current which device use?
What is maximum current which device use?

Did you check capacity of battery and power consumption of device ?

What is battery capacity?
What is average current which device use?
What is maximum current which device use?

& battery which is built in we commonly observed in somtimes in microprocessors,cordless landline sets etc etc
i am showing some figures here

in some cases i saw this one

View attachment 90763View attachment 90763

in some i hv seen this

View attachment 90764

but in some i hv seen BL-4C model basically in NOKIA set

Well china made MP-4 players need BL-4C basically
(JXD models)

#### tpetar

Read information for capacity usually its written on battery body.

Use ampermeter to measure current consumption.

battery which is built in we commonly observed in somtimes in microprocessors,cordless landline sets etc etc

What do you mean? Device have builtin battery inside?

But how you then try mobile phone or other battery in this device, what you mention in first post?

What I know uC uCPU dont have battery inside, but I know one uC which have battery inside and its DS5000T. Its Maxim-Dallas uC from 8051 family, this uC have RTC inside and use battery to keep RTC live.

#### rajaram04

Don't know sir but in schooling time i saw in a 8085 uP supporting kit then i started searching for this battery & i got it

I replaced the battery of my cousin's simple usb player & got expectable results

One of JXD ipod i saw containing a same BL-4C battery as we use in nokia set

it doesn't matter what battery but the issue is all this gr8 events we operate on 3.6 volts but if we buy a circuit & make connections as per labelling it needs pure 5 volts & too with an adapter or say a transformer supply

Why so ?

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One more thing that in available open circuit they also do not mention parameters

have a look on example

#### SANDEEP ANAND

its an Mp3 decoder chip/circuit/board and FM radio too works well on 3-5 volt

You need to understand that logic 1 and logic 0 are not purely 5 V and 0V as we expect but they are designed for a range of values varies from 3V to 5V and the logic 0 varies from 0V to around 1V depending upon the device.Refer this page,
HTML:
http://en.wikipedia.org/wiki/Logic_level
So in order for a device to work,it must be within this range and it must be able to supply the amount that it is designed to supply.But the best performance will be achieved only when we give proper 5 V as there will always voltage drop in subsequent stages in the circuit.It will work best if the voltage levels doesn't go to the float level.

#### rajaram04

You need to understand that logic 1 and logic 0 are not purely 5 V and 0V as we expect but they are designed for a range of values varies from 3V to 5V and the logic 0 varies from 0V to around 1V depending upon the device.Refer this page,
HTML:
http://en.wikipedia.org/wiki/Logic_level
So in order for a device to work,it must be within this range and it must be able to supply the amount that it is designed to supply.But the best performance will be achieved only when we give proper 5 V as there will always voltage drop in subsequent stages in the circuit.It will work best if the voltage levels doesn't go to the float level.

float level you mean ?

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its an Mp3 decoder chip/circuit/board and FM radio too works well on 3-5 volt

hmm ya right i use to make usb player with such decoders as per use but fully i don't know to connect sd card as a option i found on this chip & too on remote unit , but don't know much . . well i usually apply 5 volts by means of 7805 or like that but now i want to operate it on 3.6 volts mobile battery , so as you said i guess i can proceed in a simple way , right ?

#### Audioguru

A Nokia BL-4C battery is Lithium, not Ni-MH. It is 4.2V when fully charged, average discharging voltage is 3.7V and minimum voltage where the electronics are supposed to be turned off is 3.2V. Many BL-4C batteries are 800mAh. My HP camera has a similar HP battery. It is 1100mAh.

I mean the level between the Logic 0 and logic 1 voltage level.

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#### rajaram04

A Nokia BL-4C battery is Lithium, not Ni-MH. It is 4.2V when fully charged, average discharging voltage is 3.7V and minimum voltage where the electronics are supposed to be turned off is 3.2V. Many BL-4C batteries are 800mAh. My HP camera has a similar HP battery. It is 1100mAh.

hmm so it possible to drive such mp3 chip circuitries with 800 mah 3.7 volts battery ???? or we need to introduce some extra things ???????

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I mean the level between the Logic 0 and logic 1 voltage level.

i see . . well let see . i ve to analyse all these first

#### Audioguru

hmm so it possible to drive such mp3 chip circuitries with 800 mah 3.7 volts battery ????
Only if the MP3 circuit works when its supply voltage is from 3.2V to 4.2V. If it draws 20mA then it will run for 800mAh/20mA= 40 hours.

#### rajaram04

Only if the MP3 circuit works when its supply voltage is from 3.2V to 4.2V. If it draws 20mA then it will run for 800mAh/20mA= 40 hours.

hmm so how could it be possible to identify a circuit's power requirement ???

#### Audioguru

hmm so how could it be possible to identify a circuit's power requirement ???
Simply measure its supply current with a current meter in series between the battery and the MP3 player.

#### SANDEEP ANAND

Simply remember

watt = volt x ampere

#### rajaram04

Simply measure its supply current with a current meter in series between the battery and the MP3 player.

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 ?

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Simply remember

watt = volt x ampere

heheh soi big , ya ya thats ok volt x amp. Vmax or Vmin. for the circuit ?

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