Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Open Circuit Voltage

Open Circuit Voltage

Open Circuit Voltage

I have two batteries in series with a circuit breaker in between to enable isolation for servicing. When the breaker is on/closed I read 2S voltage. When the breaker is off/open I read 1.95S volts. Breaker is rated plenty high for service voltage. Breaker appears to be functional, I verified by disconnecting the lugs on battery #2 and then checking voltage output on the breaker in the off position and voltage was 0. Something about having a battery on both sides of a breaker is problematic? I assume I can just go to a switch but thought I could protect from overcurrent during operation without a fuse.


RE: Open Circuit Voltage

Because so many battery systems are ungrounded, one needs to ask, how are you measuring the voltage?
And what is with the S after the voltage reading?
Do you have a charger on these batteries? And by opening the breaker, are you removing it?

RE: Open Circuit Voltage

A simple schematic with your two conditions complete with your metering locations would facilitate more focused suggestions.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close