×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

Battery

Battery

(OP)
Good Day..
I just want ot ask if how many Dichroic Halogen Bulb, rated 20W, 12V..can i connect to the 12V LEad Acid Battery, 29Plates, 200Ahr..for only 5mins per day... I am just very confused with the capacity of the battery (e.g. 200Ahr)...and the load that it could carry for a specific time..tnx...

RE: Battery

20W/12V = 1.7A

20A/1.7A = 11  For rated charge over 10 hrs.

But since you say only 5 minutes we can up that - considerably.

I'd guess a maximum current of about 400A for 5 minutes.

400A/ 1.7A = 235

This would demand exacting wiring or a fire will result.  It's also going to be creating 4800W of heating.  That's two or three electric range top burners on HIGH.

You would also need to fully recharge the battery immediately after this or risk sulfation and rapid capacity loss.

But of course this is only an educated guess. The number you left out was the maximum allowed discharge rate of your battery.  It could be less than 400A as it depends on the battery's construction.

 

Keith Cress
kcress - http://www.flaminsystems.com

RE: Battery

Automotive and marine battery cold cranking amperage is specified for only 30 seconds.  So that means a car battery with CCA rating of 800 A would only sustain perhaps 80A for 5 minutes

TTFN

FAQ731-376: Eng-Tips.com Forum Policies

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!


Resources