Battery Power Our Systems?

My car radio, similar FM module...


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There are many people selling these assembled amplifiers.
The FM modules come in average and good quality versions, and a new version has come with a different shape and bigger buttons, same type display.
FM modules and ICs are imported, cheap versions have cheap capacitors, expensive ones get Keltron capacitors.
Resistor, PCB, pots. soldering etc. is done locally, mostly in Delhi area.

The (discontinued by Sanyo) 4440 IC has been copied by the Chinese, about 25 Rupees each, assembled and populated PCB is about 225 Indian Rupees. 0-12V AC supply, or 12V DC. 6W/channel in single, or 19W in BTL.
Mostly 2 IC BTL mode boards are sold.
2030 based boards also about same price, but needs 12-0-12V supply.

You can search on Indian sites, most are very cheap, the car radio was about 350 Indian, the AC powered one was 750 Indian Rupees.
Currently the US Dollar is about 83 Rupees.
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Can you hear the difference between class A, AB and D? Or, more to the point, do similarly priced amplifiers in each of the classes sound as good as each other? So far, I have not liked the sound of class D, however a well designed one should be able to impress. Waiting for my PAM 8403 board.
Yes, I don't think the issue with the power available from the batteries.... I think the issue is to remove the AC component.

Remove the PS from the amp chassis, move it to a separate box. Feed an umbilical with DC to the amp chassis. So far, so good.

Then install a secondary capacitor banks in the amp chassis for additional filtering.

Get a big battery bank, go through a transformer and feed DC to the amp via an umbilical.

Put a switch at the amp to select between the AC power supply or the battery power supply.
Also speaker impedance, as I have just found out, running off a battery is fine if I hook up two 8 Ohm speakers in series but not with two 4 Ohm speakers in series, which is curious since the LM 386 gives a minimum impedance of 4 Ohms as a specification, although in some forums using a 4 Ohm speaker with this amp has been advised against.
I am running my LM386 off batteries - I noticed that the 9V battery is not rather depleted and cannot power the amplifier without distortion at even low volume levels. The voltage reading, however, is about 6V. Connecting 3 AAA batteries which have a maximum of 4.5 V, I can run louder without so much distortion.
It is not the voltage reading that is important, then, but the rate of discharge (as mentioned by a member) that is important here.

I changed my diagram: Is this correct?



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