user8060: I'm trying to build a tiny project. After I program the board, to power the dev board - how can I power it to run the code?
Question:

I was curious as to how I would be able to power the ATtiny85 USB Mini Dev Board by using a 90mAh 3.7V LiPo battery which is connected to a TP4056 5V micro USB Lipo battery charger? The power is regulated to 5V by a  3v to 5v 1a USB Charger DC-DC Converter feeding the 5V pin on the ATtiny85.
If now, how else can I power the ATtiny85 USB Mini Dev Board with a rechargeable battery?

New Circuit

Old Circuit


Final Circuit


user23644: The old circuit will not work as you expect. While the ATtiny85 can run happily with 2.7 to 5.5V in this setup it expects 5V. I assume this is due to the high CPU clock setting. To run stable at a high CPU clock it requires 4.5V.
The VIN pin is connected to a linear regulator that has a 2V drop-out. Thus the supplied voltage has to be at least 2V about the target voltage. That is why the shopping page states a 5V (direct) or 7-35V (regulated at VIN) power supply.
Your LiPo charger already has a boost converter built in that boosts the battery voltage (3.0 - 4.2V) to 5V. No need to use a separate DC-DC boost converter here.  
Just connect OUT+ to 5V and you are done.

8060: <p>I'm trying to build a tiny project. After I program the board, to power the dev board - how can I power it to run the code?</p>

<p><strong>Question:</strong></p>

<ul>
<li>I was curious as to how I would be able to power the <a href="https://www.electrodragon.com/product/attiny85-usb-mini-dev-board-digispark-compatible/" rel="nofollow noreferrer">ATtiny85 USB Mini Dev Board</a> by using a <a href="https://www.ebay.com.au/i/113322553296?chn=ps" rel="nofollow noreferrer">90mAh 3.7V LiPo</a> battery which is connected to a <a href="https://www.ebay.com.au/itm/1-2-5-10-TP4056-5V-Micro-USB-Lithium-Bat-Charging-NEW-Improved-LiPo-Charger-Mod/182632018873?hash=item2a85b773b9:m:m0nABi0ToNRyNEbNtzeAAFQ:rk:1:pf:0" rel="nofollow noreferrer">TP4056 5V micro USB Lipo battery charger</a>? The power is regulated to 5V by a  <a href="https://www.ebay.com.au/p/2pcs-3v-to-5v-1a-USB-Charger-Dc-dc-Converter-Step-up-Boost-Module/1663444523?iid=191674152965&amp;chn=ps" rel="nofollow noreferrer">3v to 5v 1a USB Charger DC-DC Converter</a> feeding the 5V pin on the ATtiny85.</li>
<li>If now, how else can I power the <a href="https://www.electrodragon.com/product/attiny85-usb-mini-dev-board-digispark-compatible/" rel="nofollow noreferrer">ATtiny85 USB Mini Dev Board</a> with a rechargeable battery?</li>
</ul>

<p><strong>New Circuit</strong>
<a href="https://i.stack.imgur.com/EiUF6.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EiUF6.png" alt="enter image description here"></a></p>

<p><strong>Old Circuit</strong>
<a href="https://i.stack.imgur.com/jxD4u.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/jxD4u.png" alt="enter image description here"></a></p>

<hr>

<p><strong>Final Circuit</strong></p>

<p><a href="https://i.stack.imgur.com/eGiHo.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eGiHo.png" alt="enter image description here"></a></p>
 23644: <p>The old circuit will not work as you expect. While the ATtiny85 can run happily with 2.7 to 5.5V in this setup it expects 5V. I assume this is due to the high CPU clock setting. To run stable at a high CPU clock it requires 4.5V.</p>

<p>The VIN pin is connected to a linear regulator that has a 2V drop-out. Thus the supplied voltage has to be at least 2V about the target voltage. That is why the shopping page states a 5V (direct) or 7-35V (regulated at VIN) power supply.</p>

<p>Your LiPo charger already has a boost converter built in that boosts the battery voltage (3.0 - 4.2V) to 5V. No need to use a separate DC-DC boost converter here.  </p>

<p>Just connect OUT+ to 5V and you are done.</p>
