Espruino Wifi battery?

Initially, I posted what's below the ////////////// line. ooops... What was I thinking... Lipo?... which goes 'way' beyond the max rating... sorry for confusion.

Anyway, this is the update and good news:

** You are perfectly fine to connect this battery directly to the 3.3V because its highest voltage and worst case is below the maximum ratings. I attached the power schema and maximum rating of the mc from the manual linked on Espruino Pico Reference page. **

Notes:

• VDD in attached Power Supply Schema is what is directly connected to the 3.3V 'pin' of the Espruino (boards).
  
• Voltage regulator in attached Power Schema is the processor's own and internal core voltage regulator and not the 3.3V voltage regulator I refer to in my post.
  
• The 3.3V voltage regulator I refer to in my post is the one on the board that allows to run PICO on USB 5V voltage (and higher... up to 16 volts... which means: you can connect it to a 12V (car) battery (when you have spike suppression/filter; which can be is as simple as thru a 'low-ohm' resistor and then a 'fat' capacitor across 12V and GND; better is though a 'zorp' -Transient-voltage-suppression diode - instead (or) parallel to the capacitor)).
  
  

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As stated earlier, you may have various issues by directly connecting this battery to 3.3V:

• When you connect it directly to to 3.3V and it is fully charged, you may have too high voltage
  
• When you connect it to 5V (to power the Espruino through the 3.3V voltage regulator), you may not have enough voltage.
  
  

As you can see from the various graphs in attached battery spec file, you see the voltage from every cell from beginning to be too hight to continuously dropping. It gets really low when approaching 80% discharge... (C in attached graph means Nominal Charge - 1C means 600mA discharge over 1hr, 0.2C means 120mA discharge over 5hours).

These batteries are really great and work nicely for where they are used: cordless phone that you use while talking, but then you put it back on the station where they get recharged...

Using 4 such cells are perfect and give you ample reserve to run through the 3.3V voltage regulator to give you a stable power supply even beyond 80% discharge. You can get them in AA or AAA size and nice battery holders for 4 cells as well, and you can charge them with conventional chargers.

PS: ...have not stakes in organization from where I pulled the tech file, but it is an excellent piece of pager explaining many things greatly...

4 Attachments

• nickelmetalhydride_appman.pdf
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