user66937: I working on the system where ESP8266-01 should continuously on because I want to get the Wi-Fi function on. In that case ,I can't use the Sleep mode which is given in the Esp8266-01 . So, My Question is that "How much will current(mA) dropped if the esp8266-01 continuously on in 4.2 LiPo battery??

user14490: The short answer is - we don't know.
Longer answer:
It depends on such factors as:

The board circuit (the BBBL (known as The Big Bright Blue LED) on some boards could drain about 10-20ma only by itself)
The voltage regulator efficiency
The battery controller circuit / quality / keying efficiency.

The reasonable value is about 170-220 mA (taken from the PDF, section 5.2) for continuous data transfer.

The true solution is:
Take the ammeter, connect it in series with the battery and measure.

user40409: If you really don't sleep at all you can count with about 70 mA, with some short spikes when transmitting.
Sleep mode disabled:

(100 mA per division)
But you don't need to disable sleep mode completely to use Wifi, you can be in Auto Light Sleep, which I think is the default for Arduino, Non-OS and RTOS.
Auto Light Sleep:

(100 mA per division)
The Wifi will automatically wake up to transmit and it will also wake up according to the Access Points DTIM interval to receive (usually every 300 ms). You're looking at about 2 mA baseline consumption plus the Wifi send and receive spikes.
Unfortunately after bootup there is a 10 second interval with full 70 mA consumption before the Auto Light Sleep mode kicks in. That's a significant drain if you have frequent system resets, but it might have been a bug that has been fixed in the meantime. (I took those measurements in 2017 with the Arduino SDK.)
There are other modes, but these were the ones that matter in your case.

66937: <p>I working on the system where ESP8266-01 should continuously on because I want to get the Wi-Fi function on. In that case ,I can't use the Sleep mode which is given in the Esp8266-01 . So, My Question is that &quot;How much will current(mA) dropped if the esp8266-01 continuously on in 4.2 LiPo battery??</p>
 14490: <p><strong>The short answer</strong> is - we don't know.</p>
<p><strong>Longer answer</strong>:
It depends on such factors as:</p>
<ol>
<li>The board circuit (the BBBL (known as The Big Bright Blue LED) on some boards could drain about 10-20ma only by itself)</li>
<li>The voltage regulator efficiency</li>
<li>The battery controller circuit / quality / keying efficiency.</li>
</ol>
<p><strong>The reasonable value</strong> is about 170-220 mA (taken <a href="https://www.espressif.com/sites/default/files/documentation/0a-esp8266ex_datasheet_en.pdf" rel="nofollow noreferrer">from the PDF</a>, section 5.2) for continuous data transfer.</p>
<p><a href="https://i.stack.imgur.com/wlcVO.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wlcVO.png" alt="enter image description here" /></a></p>
<p><strong>The true solution is</strong>:
Take the ammeter, connect it <em>in series with the battery</em> and measure.</p>
 40409: <p>If you really don't sleep at all you can count with about 70 mA, with some short spikes when transmitting.</p>
<p>Sleep mode disabled:</p>
<p><a href="https://i.stack.imgur.com/2W10Y.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2W10Y.jpg" alt="No sleep" /></a></p>
<p>(100 mA per division)</p>
<p>But you <strong>don't need to disable sleep mode</strong> completely to use Wifi, you can be in Auto Light Sleep, which I think is the default for Arduino, Non-OS and RTOS.</p>
<p>Auto Light Sleep:</p>
<p><a href="https://i.stack.imgur.com/B1xtU.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/B1xtU.jpg" alt="Auto Light Sleep" /></a></p>
<p>(100 mA per division)</p>
<p>The Wifi will automatically wake up to transmit and it will also wake up according to the Access Points DTIM interval to receive (usually every 300 ms). You're looking at about 2 mA baseline consumption plus the Wifi send and receive spikes.</p>
<p>Unfortunately after bootup there is a 10 second interval with full 70 mA consumption before the Auto Light Sleep mode kicks in. That's a significant drain if you have frequent system resets, but it might have been a bug that has been fixed in the meantime. (I took those measurements in 2017 with the Arduino SDK.)</p>
<p>There are <a href="https://blog.creations.de/?p=149" rel="nofollow noreferrer">other modes</a>, but these were the ones that matter in your case.</p>
