Q&A: Question About Over-discharged LiPo--How do I quantify the amount of damage done to the battery pack?

By Gabriel Staples
Written: 7 Feb 2015
Last Updated: 7 Feb 2015

Related Articles:

• Restoring/Recharging Over-discharged LiPo (Lithium Polymer) Batteries!
• Parallel Charging Your LiPo Batteries
• Thunder AC680/AC6 Charger & Computer Data-Logging Software
• The Power of Arduino <-- be sure to check out the various really useful Arduino-related links at the bottom of this post!  They have helped me a ton.
• Recommended Soldering Kit & Tutorials (for Arduino, Electronics, & Radio Control)
• Beginner RC Airplane Setup

High-current bench-top battery test setup by FliteTest (source: 4:08)

Question I Just Received:
-from "Lakshman

"Hi Gabriel.
I am referring to your post http://electricrcaircraftguy.blogspot.sg/2014/10/restoring-over-discharged-LiPos.html#.VNXv9mSUcp0.

I accidentally discharged my battery to 2.8v/cell today due to a faulty lipo alarm. It did not go off at 3.6V while flying my tricopter and within a minute or so, the voltage dropped to 2.8v/cell. I recharged it back to 3.8v storage at 0.2A without any issues. This was before I read that article.

How do I quantify the amount of damage done to the battery pack? I usually stop flying at or before ~80% discharge. Will it be a lousier battery after this incident?

Thank you."

Here's what I had to say...

Restoring/Recharging Over-discharged LiPo (Lithium Polymer) Batteries!

By Gabriel Staples
Written: 5 March 2014
Posted Here: 13 Oct. 2014
Last Updated: 7 Feb. 2015
-added Q&A section & link - 7 Feb. 2015

Related Articles:

• Parallel Charging Your LiPo Batteries
• [NEW!!] Question About Over-discharged LiPo--How do I quantify the amount of damage done to the battery pack?
•  [NEW!] Recommended Soldering Kit & Tutorials (for Arduino, Electronics, & Radio Control)
• Beginner RC Airplane Setup
• Thunder AC680/AC6 Charger & Computer Data-Logging Software

Recommended Arduino Articles:

• Using the Arduino Uno’s built-in 10-bit to 21-bit ADC (Analog to Digital Converter) (via eRCaGuy_NewAnalogRead library)
• Arduino micros() function with 0.5us precision - using my Timer2_Counter Library
• eRCaGuy_ButtonReader Library for Arduino - Debounce and read the current button or switch state, & most recent action ("just pressed" or "just released") easily!
• The Power of Arduino <-- be sure to check out the various really useful Arduino-related links at the bottom of this post!  They have helped me a ton.
• Arduino Power, Current, and Voltage Limitations
• Quick Tip: 4 Ways to Power an Arduino

Though I first posted this article on my Instructables page, I decided to update it and repost it on my main website here in order to keep my articles more consolidated and easily maintained by myself.  From this point on, I will keep the most up-to-date version of this article right here, instead of on my Instructables page, so if you want the latest info, read here.  Don't forget to subscribe to receive an email whenever I post something new by clicking the subscribe link at the top-right of this page!  I will never use your email addresses for spam.

A LiPo that self-discharged, while in my plane, hanging overnight in a tree. :(

Intro:

LiPo batteries should never be discharged below 3.0V/cell, or they may be permanently damaged.  Many chargers don't even allow you to charge a LiPo battery that is below 2.5V/cell.  So, if you accidentally run your plane/car too long, you don't have your low voltage cutoff set properly in the ESC (Electronic Speed Controller), or you leave the power switch on, forget to unplug the LiPo, get your plane stuck overnight in a tree (the same tree, three separate times, for foolishly flying in areas too small because you are too excited to fly and it's almost dark), etc. etc., you may find yourself in a situation where you've discharged your LiPo down well below 3.0V/cell.  What do you do?

Many people toss the LiPos in the trash.  I don't.  I restore them.  Here's how.

Recommended Soldering Kit & Tutorials (for Arduino, Electronics, & Radio Control)

By Gabriel Staples
Written: 14 June 2014
Posted to blog: 3 Aug. 2014
Last Updated: 26 May 2018
History (newest on TOP):
-20180526: Added Velleman desoldering review & link.
-20170415: converted basic Amazon links to Amazon Affiliate links; updated many of the solder links too, and prices on many links
-20161126: updated many links, incl the broken ones from Radio Shack; also added several new sections, including bonus soldering irons, rosin flux, high-power irons & torches, acid-core solders & acid fluxes, & how to tin a soldering iron tip.
-20141008: added an advanced "drag soldering" link at bottom
-20140905: added more soldering iron links, & solder tip tinner/cleaner link, as well as quite a bit more info.
-20140830: added more info about soldering irons "for Radio Control" use; also added "intermediate" links to the soldering tutorials section at the end

Related Articles:

• Heavy Duty Connectors and Large Gauge Wire, & XT60 Soldering Experiment - using my $8, 60W Hobbico iron from Tower Hobbies
• The Power of Arduino <-- be sure to check out the various really useful Arduino-related links at the bottom of this post!  They have helped me a ton.
• The Goal of a Lifetime
• Arduino micros() function with 0.5us precision - using my Timer2_Counter "Library"
• Arduino Power, Current, and Voltage Limitations
• Quick Tip: 4 Ways to Power an Arduino
• Parallel Charging Your LiPo Batteries
• Beginner RC Airplane Setup
• Thunder AC680/AC6 Charger & Computer Data-Logging Software
• All articles on my blog with the label "Arduino" - http://electricrcaircraftguy.blogspot.com/search/label/Arduino
• Thunder AC680/AC6 Charger & Computer Data-Logging Software
• Parallel Charging Your LiPo Batteries

Here is a list I put together to help people get into soldering & electronics.

DIGITAL GENUINE HAKKO FX-888D, from Adafruit.com

Keep reading below for more info.

eRCaGuy_ButtonReader Library for Arduino - Debounce and read the current button state, & most recent action ("just pressed" or "just released") easily!

By Gabriel Staples
Written: 31 May 2014
Last Updated: 25 July 2015
Article History (newest on top)
-added button image & updated download links - 25 July 2015

Other Articles to Check Out:

• The Power of Arduino <-- be sure to check out the various really useful Arduino-related links at the bottom of this post!  They have helped me a ton.
• The Goal of a Lifetime
• Arduino micros() function with 0.5us precision - using my Timer2_Counter "Library"
• Arduino Power, Current, and Voltage Limitations
• Quick Tip: 4 Ways to Power an Arduino
• Parallel Charging Your LiPo Batteries
• Beginner RC Airplane Setup
• Thunder AC680/AC6 Charger & Computer Data-Logging Software
• All articles on my blog with the label "Arduino" - http://electricrcaircraftguy.blogspot.com/search/label/Arduino

This Article:

Library History (newest on top):

20141031: major bug fix; added multi-button support with a new 5-button-reader example!
20140531: first release.

Misc. push buttons which can greatly
benefit from digital debouncing. 
(Image source here).

Summary:

I wanted a simple and universal, yet very powerful & reliable library to read a button or switch in such a way that I can easily implement toggled actions and momentary actions, know the true, debounced state of a button or switch at any given time, and specify whether I want an action to take place when the button is *pressed* or *released.* This library makes implementing all of these things easy for me, and I now use it on all of my projects that require reading a button or switch, so I wanted to share it with others. Hopefully you find it useful too. Check out the included examples.  

This code is an elaboration of, and library form of, the main Arduino-sponsored "Debounce" example found here.  Thanks to David A. Mellis, Limor Fried (LadyAda), and Mike Walters for writing that excellent and well-thought-out example code.

Download:

Download eRCaGuy_ButtonReader

(Optionally) donate, & download via the link just above, or by clicking here then choosing the appropriate download.  Install the library into the Arduino IDE (using Sketch --> Include Library --> Add .ZIP Library), then run the examples to see how to use the library.

Using the Arduino Uno’s built-in 10-bit to 16+-bit ADC (Analog to Digital Converter)

By Gabriel Staples Written: 13 May 2014
Last Updated: 16 Sept. 2015

History (newest on top):
-16 Sept 2015 - changed title from "10-bit to 21-bit ADC..." to "10-bit to 16+-bit ADC..."
-25 July 2015 - added a brief update below, updated download links
-17 Feb. 2015 - changed latest link to new release: V2.1 alpha, in yellow below
-24 Jan. 2015 - added link to Version 2.0 alpha below...allows sampling rates of ~50+ kHz, and fixed bug to allow >16-bit samples to not have computation errors

A Few Other Articles to Check Out:

• eRCaGuy_ButtonReader Library for Arduino [JUST UPDATED] - Debounce and read the current button or switch state, & most recent action ("just pressed" or "just released") easily!
• The Power of Arduino <-- be sure to check out the various really useful Arduino-related links at the bottom of this post!  They have helped me a ton.
• The Goal of a Lifetime
• Arduino micros() function with 0.5us precision - using my Timer2_Counter "Library"
• Arduino Power, Current, and Voltage Limitations
• Quick Tip: 4 Ways to Power an Arduino
• Parallel Charging Your LiPo Batteries
• Beginner RC Airplane Setup
• Thunder AC680/AC6 Charger & Computer Data-Logging Software
• All articles on my blog with the label "Arduino" - http://electricrcaircraftguy.blogspot.com/search/label/Arduino

This Article:

Using the Arduino Uno’s built-in 10-bit to 16+-bit ADC (Analog to Digital Converter)???
--Wait, what did you say!? I thought that Arduinos only had a 10-bit ADC!  How can you get, for example, 16-bit resolution out of a 10-bit ADC?  Well, the answer is oversampling.  Atmel has written a really good article about it called "AVR121 Enhancing ADC resolution by oversampling."

Before I continue, I'd like to give a special thanks to user "fat16lib," on the Adafruit Forums, who first made this technique known unto me by his post right here, thereby inspiring me to write this, my first ever, library.

Now on to the library: