Storing Cookies (See : http://ec.europa.eu/ipg/basics/legal/cookies/index_en.htm ) help us to bring you our services at overunity.com . If you use this website and our services you declare yourself okay with using cookies .More Infos here:
https://overunity.com/5553/privacy-policy/
If you do not agree with storing cookies, please LEAVE this website now. From the 25th of May 2018, every existing user has to accept the GDPR agreement at first login. If a user is unwilling to accept the GDPR, he should email us and request to erase his account. Many thanks for your understanding

User Menu

Custom Search

Author Topic: Measuring and Calculating Battery Capacity "Wasted" or Remaining  (Read 5607 times)

TinselKoala

  • Hero Member
  • *****
  • Posts: 13958
This is important information for anyone experimenting with devices that use or charge batteries while running.

How much energy capacity in a battery? How can you tell how discharged a battery is, or to put it another way, how much useful energy is there remaining?

Dave at EEVBlog shows us how:

http://www.youtube.com/watch?v=1hs_9vx9APw

Pirate88179

  • elite_member
  • Hero Member
  • ******
  • Posts: 8366
Re: Measuring and Calculating Battery Capacity "Wasted" or Remaining
« Reply #1 on: July 30, 2015, 04:10:01 AM »
This is important information for anyone experimenting with devices that use or charge batteries while running.

How much energy capacity in a battery? How can you tell how discharged a battery is, or to put it another way, how much useful energy is there remaining?

Dave at EEVBlog shows us how:

http://www.youtube.com/watch?v=1hs_9vx9APw

I really like Dave and have learned a lot from watching his videos.

Bill

MarkE

  • Hero Member
  • *****
  • Posts: 6830
Re: Measuring and Calculating Battery Capacity "Wasted" or Remaining
« Reply #2 on: July 30, 2015, 05:39:08 AM »
This is important information for anyone experimenting with devices that use or charge batteries while running.

How much energy capacity in a battery? How can you tell how discharged a battery is, or to put it another way, how much useful energy is there remaining?

Dave at EEVBlog shows us how:

http://www.youtube.com/watch?v=1hs_9vx9APw
It is a well done video.  I have a couple of objections, but they are minor and he addressed one in his overlay comments.  People who experiment with batteries should pay attention to the need to actually test remaining capacity by discharging the battery into a load until it is effectively dead.

TinselKoala

  • Hero Member
  • *****
  • Posts: 13958
Re: Measuring and Calculating Battery Capacity "Wasted" or Remaining
« Reply #3 on: July 30, 2015, 06:10:31 AM »
I think that the video contains some information that may help recycling, charging pulse-motor builders understand how their run batteries can show little or no voltage drop on a multimeter while the motor runs for so long. The voltage when the pulse is _off_ is essentially the noload terminal voltage of the battery. But the voltage when the pulse is _on_ drops, and it drops more and more as the battery's capacity is used up. So while the no-load voltage curve is still relatively flat, the loaded voltage curve drops off more steeply.
The multimeter displays the average voltage fairly accurately even of a pulsed voltage. So with the very short _on_ duty cycles that these motors use, the average battery voltage shown on the DMM will be close to the no-load voltage and will remain fairly constant even as the loaded (pulse on) voltage drops off.