I don't really ever calculate AH, so I am not the best person to ask, and I don't think AH works well with capacitors anyways, but a 1F capacitor will drop 1V for each second that 1A of current is drawn from it. There's 3600 seconds in an hour, so if you have a no leakage capacitance of 3600F, then you can expect 1A of current over an hour for each volt that drops across the capacitor/parallel capacitors. You can increase the voltage by putting them in series, but then the capacitance goes down, and you need protective circuitry to prevent any from over charging or discharging into negative territory since they are almost certainly polarized (balancing). That sounds like a fun project though! I will be doing some like that some day. Good thing is that you can start small scale by making the circuit(s) with low capacitance capacitors, that are safer to use, and working your way up while fixing any issues that arise.
I thought it was a voltage sensor / comparater to switch on those discharge resistors through the MOSFET (the other larger component) so that that cap will not exceed 2.7v.
lmao.... this is the down side of using that crap on top. AND the resistors that help regulate the voltage, leak them down so they are the same as the others. I have seem these without the board on top and after 3 days are virtually the same ans the start voltage.
I bought one of these on Ebay. None of the capacitors were more than 400F each one was 300F Another one was so bad it would not hold a charge more than a couple hours. They refunded me $8.00 for one of the capacitors being so bad. I would of asked for another $8.00 for the one that was 300 F but did not notice till much later. Another seller was selling capacitors in groups of 5 that were labeled as Maxwell I had bought 10 They we all different lengths and even had the wrong model number printed on them. They were all fakes I got refunded on all of those then they quickly removed the listing. I would not purchase capacitors on E bay from Chinese sellers again. There are so many that are junk and fakes. I will only buy from Amazon from now on.
Yeah, I definitely would never recommend buying them from EBay for a serious project. They are a good price in my opinion for playing around with but that's about it. My first purchase from an official electronics supplier like digikey will mist certainly be for quality supercaps or hard to find transistors. I prefer to get from Amazon whenever possible.
So you think the Amazon distributors are not in China? I think you may be surprised. Also if you think that your local warehouses are not supplied from China again you are up for surprise. BTW I bought two different Li-Ion batteries made in China one for laptop one for vacuum - disaster in both cases neither of them had balancing board nor thermistors. It's not to say that there cannot be good products made in China, just some of them lack quality control and traditionally if they can get advantage of the westerner they will...
I thought that the capacitor is better than batteries... its useless to put blocking diode..since it leaks in capacitor itself..I thought it is better than battery..Id cancelled my order capacitor instead I go to primitive ever reliable lead scid battery..thanks at least it gives me enlightenment.. Godbless
Capacitors in series do get divided. If they are all the same and you have 6 500 Farad 2.7 V capacitors in series you end up with an equivalent 83.3F capacitor at 16.2V I tested this formula and it is true. Try it yourself and then do a test and see what you come up with and you will understand.
Do you use fuse to protect the capacitor while charge it?
I haven't, but it's a good idea to.
Very few videos on balancing a supercapacitor using the SABMOSFETs. It would be nice to see one since there is only one about these.
I'll keep that in mind!
Thank you for your info.
Thanks for watching!
How do you check the AH capacity for these when fully charged? I'm thinking about making one of these with a hand crank+ inverter.
I don't really ever calculate AH, so I am not the best person to ask, and I don't think AH works well with capacitors anyways, but a 1F capacitor will drop 1V for each second that 1A of current is drawn from it. There's 3600 seconds in an hour, so if you have a no leakage capacitance of 3600F, then you can expect 1A of current over an hour for each volt that drops across the capacitor/parallel capacitors. You can increase the voltage by putting them in series, but then the capacitance goes down, and you need protective circuitry to prevent any from over charging or discharging into negative territory since they are almost certainly polarized (balancing). That sounds like a fun project though! I will be doing some like that some day. Good thing is that you can start small scale by making the circuit(s) with low capacitance capacitors, that are safer to use, and working your way up while fixing any issues that arise.
I thought it was a voltage sensor / comparater to switch on those discharge resistors through the MOSFET (the other larger component) so that that cap will not exceed 2.7v.
Sounds good :)
A strip of wide foam tape across the bottom of the PCB will protect the delicate SMD components.
Yeah. I'm disappointed that it doesn't come covered.
I have the same (or similar) board and found that 2 of the 6 capacitors lost charge significantly. The other 4 caps were ok.
Thanks for the info!
It is a diode to prevent reverse flow of power
Pretty good. I aced it.
Great!
lmao.... this is the down side of using that crap on top. AND the resistors that help regulate the voltage, leak them down so they are the same as the others. I have seem these without the board on top and after 3 days are virtually the same ans the start voltage.
Yeah, I am working on DIY alternatives unless I find something better. Thanks for watching!
I bought one of these on Ebay. None of the capacitors were more than 400F each one was 300F Another one was so bad it would not hold a charge more than a couple hours. They refunded me $8.00 for one of the capacitors being so bad. I would of asked for another $8.00 for the one that was 300 F but did not notice till much later. Another seller was selling capacitors in groups of 5 that were labeled as Maxwell I had bought 10 They we all different lengths and even had the wrong model number printed on them. They were all fakes I got refunded on all of those then they quickly removed the listing. I would not purchase capacitors on E bay from Chinese sellers again. There are so many that are junk and fakes. I will only buy from Amazon from now on.
Yeah, I definitely would never recommend buying them from EBay for a serious project. They are a good price in my opinion for playing around with but that's about it. My first purchase from an official electronics supplier like digikey will mist certainly be for quality supercaps or hard to find transistors. I prefer to get from Amazon whenever possible.
So you think the Amazon distributors are not in China? I think you may be surprised. Also if you think that your local warehouses are not supplied from China again you are up for surprise.
BTW I bought two different Li-Ion batteries made in China one for laptop one for vacuum - disaster in both cases neither of them had balancing board nor thermistors.
It's not to say that there cannot be good products made in China, just some of them lack quality control and traditionally if they can get advantage of the westerner they will...
I thought that the capacitor is better than batteries... its useless to put blocking diode..since it leaks in capacitor itself..I thought it is better than battery..Id cancelled my order capacitor instead I go to primitive ever reliable lead scid battery..thanks at least it gives me enlightenment.. Godbless
Interesting thoughts! Thanks for watching!
capacitors in series, their capacitance does not get divided or added , their voltage gets added
Capacitors in series do get divided. If they are all the same and you have 6 500 Farad 2.7 V capacitors in series you end up with an equivalent 83.3F capacitor at 16.2V I tested this formula and it is true. Try it yourself and then do a test and see what you come up with and you will understand.