# Super capacitor charging

Thread Starter

#### doller

Joined Sep 28, 2012
14
Hi all,

I am getting some 2600F, 2.5V caps and can't find much useful info how can they be charged in a reasonable amount of time, say couple of minutes.

I can work the formulas but need help with technical info that is just too hard to locate. For example a welding power supply looks like a great cheap option but can it operate "short circuited"? Welding itself looks like doing just that but I just don't know. Can I use a pc power supply? A battery charger?

#### Kermit2

Joined Feb 5, 2010
4,162
With a .1 ohm resistor to limit current to approx. 30 amps at startup(2.5 volt supply)

The cap will take around 15-20 minutes to reach 2.5 volts

Substitute a .01 ohm resistor and the time drops to 2 or 3 minutes, but the initial current draw peaks around 300 amps.

Fast can be accomplished but will take HUGE currents to get the charge time under a minute.

#### crutschow

Joined Mar 14, 2008
25,375
A DC output welder might work but you need to check its duty-cycle to see if can charge the capacitor without exceeding its rating.

How are you going to regulate the charging voltage to the cap? You could use a 2.5V voltage regulator but it could dissipate a lot of power, depending upon the source voltage, if you want a fast charge.

#### PackratKing

Joined Jul 13, 2008
847
Twenty-six Hundred Farad !!! ??? I gotta not be understanding the OP

#### crutschow

Joined Mar 14, 2008
25,375
Twenty-six Hundred Farad !!! ???
He did say it was a super capacitor.

#### JMW

Joined Nov 21, 2011
127

#### PackratKing

Joined Jul 13, 2008
847
He did say it was a super capacitor.
good grief.......I would hate to mishandle a charge like that !!

#### MrChips

Joined Oct 2, 2009
21,818
Where can you buy that? I want one... or many!

#### Audioguru

Joined Dec 20, 2007
11,249
The 3000F caps for \$25.00 each on E-Bay are USED ones.

#### PackratKing

Joined Jul 13, 2008
847
Don't know where to look yet for the conversion formula -- tho' I looked up the condensors used for starting diesel rail locomotives........[ railroad brat ] and they are listed in the neighborhood of 40 KiloJoules.......

Thread Starter

#### doller

Joined Sep 28, 2012
14
Don't know where to look yet for the conversion formula -- tho' I looked up the condensors used for starting diesel rail locomotives........[ railroad brat ] and they are listed in the neighborhood of 40 KiloJoules.......
Here you go:

#### Papabravo

Joined Feb 24, 2006
14,382
You'll shoot yer eye out kid!
-- Jean Shepherd

#### JMac3108

Joined Aug 16, 2010
348
Supercaps have a very shortened life if you exceed the 2.5V rating across them. If you put them in series you might need to take this into account...

Similar threads