Math Help ( Hey, I'm new to this stuff ) Thought it was a simple multiplication problem

4 posts / 0 new
Last post
scouttster
scouttster's picture
Offline
Last seen: 8 years 6 months ago
Joined: Monday, December 19, 2011 - 06:20
Points: 14
Math Help ( Hey, I'm new to this stuff ) Thought it was a simple multiplication problem

Gentleman is selling batteries as reads:
$58.20 for 28 = 3.7v 2400mah batteries.
Enough to make a 25.9v 9.6ah pack that works with the EZip 24v controller!

I figured he arrived at his figures by 28 X 3.7 for the voltage and 28 X 2.4 for the amphours. I was way wrong.. Can someone explain, how he arrived at 25.9 Volts and 9.6ah?
Thanks, I'm new to all this and just trying to learn.

Spaceangel
Offline
Last seen: 5 months 2 weeks ago
Joined: Wednesday, July 15, 2009 - 15:49
Points: 500
Re: Math Help ( Hey, I'm new to this stuff ) Thought it ...

I think I lost you in your typing of the number of cells and voltage pack? I want to convert my scoot to LiFePO4 and I know 4 lithium cells = 12.8 volt nominal so times 5 = a tad more than 60 volt pack but close enough I think. What exactly do you need? I am going to cut my frame to make testing and replacing easier.
Russell

KB1UKU

mf70
Offline
Last seen: 2 years 5 months ago
Joined: Friday, December 1, 2006 - 09:01
Points: 712
Re: Math Help ( Hey, I'm new to this stuff ) Thought it ...

He's building four serial strings of seven cells, and running the four strings in parallel:

7 x 3.7V = 25.9V

4 x 2.4AH = 9.6 AH

The math is correct.

Mark

mf70
Offline
Last seen: 2 years 5 months ago
Joined: Friday, December 1, 2006 - 09:01
Points: 712
Re: Math Help ( Hey, I'm new to this stuff ) Thought it ...

Oops. The board won't let me edit. To add, now, whether your simple charger will keep all these cells balanced without a BMI is another question. I don't think it will, and that's part of the reason I've still got lead in my sled.

Mark (again)

Log in or register to post comments


Who's online

There are currently 0 users online.

Who's new

  • pkvgameshouse
  • toomanyscoots
  • daftarpokerqq
  • Jacupp
  • micarr

Customize This