SailNet Community - View Single Post - Battery capacity - Peukert stuff
View Single Post
post #4 of Old 10-07-2012
Stu Jackson
Senior Member
Stu Jackson's Avatar
Join Date: Jul 2001
Posts: 1,160
Thanks: 0
Thanked 29 Times in 28 Posts
Rep Power: 16
Re: Battery capacity - Peukert stuff

Five inputs? It's too bad Adobe Reader doesn't include cut&paste, but let's start with the basics.

Cp = I (current) * exp n (from a logarithmic function of times over currents) * t (time)

That's all it does and says. The "inputs" to calculate "n" are logs of time1 and time2, over logs of I (current) 1 & 2.

Time 1, time 2, current 1, current 2 are the four variables used to calculate n. That's four.

Anyway, the answer to your question is that a bigger bank, twice the size, would have twice the time to go based on similar loads. That's all.

The part you seem to be confusing is the P (Peukert's factor) with the doubling of your bank capacity.

The P doesn't change, it stays the same based on the type of battery you have.

Does that clear it up? Based on your first post, are we using the same equation?

Stu Jackson, Catalina 34, 1986, M25 engine, Rocna 10 (22#)

Last edited by Stu Jackson; 10-07-2012 at 10:54 AM.
Stu Jackson is offline  
Quote Share with Facebook
For the best viewing experience please update your browser to Google Chrome