I have a series string of super caps made by Amperics. They are individually 80 fard 14 v ,5 in series.
They call it a 400 fard unit. I hooked them up to a 12 AGM battery with a full charge of 12.9 volts.
The caps were empty. It took about 20 minutes and the caps went to 12.6 v. Is it normal for there to be a slight
difference in voltage. I use my mini jumper cables made with 10 ga wire. Now I need to discharge them so I can handle them in a project. How would you discharge these? They are rated at 250 A.

 

hi 96,
I think you mean 5 in parallel =400F.
Use a 12V 60Watt car lamp/bulb to discharge them.
E

 

I believe super capacitors are typically rated for under 3V, so they I'm guessing they put 5 in series to get a 14V rating. In which case, five 80F capacitors in series will give you only 16F capacity. You would need 25 sets of 5 capacitors in series (total off 125 capacitors) to get 400F. If they're advertising five 80F capacitors in series as a 400F solution, you might want to call them on that.

You can discharge them using a power resistor, light bulb, motor, etc.. anything that will eat up some current and is rated for 12-ish volts. Odd that they took so long to charge, maybe your battery did not have much capacity?

 

they are 3 v so they are in series...so what is the real rating of discharge on these then?
. these were new,the manufacturer probably charged them a couple times nd then discharged them for shipping. When I got the they had 1 volt on them.
When I hooked up my full size AGM 12 volt battery and put the final jumper on(10 ga wire) there was a spark..?
Was it a bad idea to do it that way??? The car battery probably did send a fair amount of current into those empty caps...what do you think??

 

As there are 5 off 80F in series, that will give 16F at 15V.
Try charging/discharging at 1Amp.
Do you have a datasheet for the batteries you could post.?
E

 

they didnt give me any data sheet. Amperics is in California...easy to see on web...maybe there is info.
These are 400 farad caps so 5 in series is about 80 farads. I made a mistake thinking that was big enough..
I might have to add another module to get bigger cranking power. That SUCKS. I will try it as is..
Again..do you think that initial jolt from charging the way I did was damaging?
I have a Noco charger that does 3 amps...is that better?? how many amps did I send into it using the car battery?????
but its worth noting that when this module is getting charged by the alternator its going to be getting full alternator charge which is at LEAST 30 amps ,no?

 

Car batteries can deliver many hundreds of amps. Get the data sheet for the individual capacitors, that will be the best source for how much current they can handle without damage.

 

can I use a 12v cigarette lighter socket with inserted lighter to discharge this cap module?

 

Yes, but if the lighter pops out because it got hot then let it cool before pushing it back in again.

 

just one more thing and I appreciate your feedback...
when I first charged these they went up to 12.7 roughly...then the cap module quickly lost a volt..a couple hours later
I recharged them to 12.7 and they stayed at 12.5 for a couple hours and now its 12.2v.
If one of the caps were bad then it would not stay at 12.5 at all,no? it would lose that 1 volt or more
and keep doing it...so the module is ok and the caps are kind of conditioning..more or less..
what do you think..?

 

You do understand it take a small amount of the voltage/charge out every time you take a measurement don't you?

On another note, you aren't thinking of replacing a battery, to run something, with these are you?

 

People do that. Look on YouTube. I think one of the keys is to measure the starting amps with an amp clamp
and use a resistor inline to approximate that normal amp surge.

 

Sorry but can you post a link to that super cap pack? If it indeed has 5S 14V rating, then it either has to have a balancing circuit attached, or you are likely to destroy the caps when charging them, caps in series without supervision are a bad idea.

 

People do that. Look on YouTube.

Well it has to be true if it's on Youtube.

 

yes it has balancing. Well made. Not Chinese. I'm not doing anything risky. Just playin around and learning about caps etc. Its good to learn.

 

Capacitors will leak down over time. Get the data sheet for those individual capacitors, all of the info you're looking for should be in there. Including the self discharge rate.

 

People do that. Look on YouTube.

Yeah, on YouTube I've seen people build super-caps to replace the car battery. I don't think I'll be doing that. While the weight savings is fairly good the reliability is just not there. You can't park in front of the school and wait for your grandchildren, listen to the radio with the engine off for very long. And what happens that day the car won't start because the caps have gone dry?

Another thing I see on YouTube (used to look at - won't anymore) is a device called an "Over Unity" device where you see someone use a motor to power a generator that powers the motor and several other pieces of equipment at the same time. Physics law says it's impossible to get more energy OUT of something than you put INTO it. Just because you see people do it on YouTube doesn't mean it's possible. As for replacing a car battery - yeah, that's doable. But is it practical? Is it reliable? Two questions I need to see overwhelming evidence to the positive before I'll even THINK of doing it on my nice new truck. OK, it weighs less. How much gasoline will that save? In stop-and-go traffic it will save a little but I couldn't speak to how much it would save. I'd suspect it's not worth the effort versus the reliability of a good old practical car battery. A proven technology that will one day change. I'm just not ready to make that change.

 

People do that. Look on YouTube.

Do some more research into them and you can/will see for your self.

"The supercapacitor is often misunderstood; it is not a battery replacement to store long-term energy. If, for example, the charge and discharge times are more than 60 seconds, use a battery; if shorter, then the supercapacitor becomes economical.

Supercapacitors are ideal when a quick charge is needed to fill a short-term power need; whereas batteries are chosen to provide long-term energy. Combining the two into a hybrid battery satisfies both needs and reduces battery stress, which reflects in a longer service life. Such batteries are being made available today in the lead acid family.

Supercapacitors are most effective to bridge power gaps lasting from a few seconds to a few minutes and can be recharged quickly. A flywheel offers similar qualities, and an application where the supercapacitor competes against the flywheel is the Long Island Rail Road (LIRR) trial in New York. LIRR is one of the busiest railroads in North America."

The above is from - https://batteryuniversity.com/learn/article/whats_the_role_of_the_supercapacitor
you should really go there and read the whole thing.

 

The above is from - https://batteryuniversity.com/learn/article/whats_the_role_of_the_supercapacitor
you should really go there and read the whole thing.

Good link. Thanks.

 

Thanks Tony, but it doesn't feed the OPs narrative and he needed to try another thread to prove he's right.