#91 Electrolytic capacitors and its LEAKAGE current and how to test 

Excellent video, this topic is the most important for me, another little thing that I have found which is also just as important is keeping a stockpile of capacitors, which we all do! But after a while they start to kinda die off. They are not dead but more like in a coma! It's nice to have plenty capacitors in stock because waiting for new capacitors to show up is a pain and it kills motivation. The problem that I have found is that when we have had capacitors sitting around waiting for the next job, we don't really test them before we put them in! I know what people think about reforming capacitors but I have found that if you take the time to put a voltage on them, start low and slowly bring up the voltage a step at a time, you can wake them up and they will be restored to their new condition, but if you just put it in circuit, they get a shock and begin to heat up which really shortens their lives, sometimes they even explode! I went through a phase some time ago where I was just buying capacitors! I don't know why but I just loved all the different sizes, colours, styles and shapes. I realized that something was wrong when I was looking for a capacitor with low ESR and leakage and I just couldn't find one in my stock! So I began to systematically go through everything that I had and it looked like 95% had gone bad! I have a lot of capacitors LoL.. So I tried to reform a few and they actually started to wake up! So what I have learned is that Capacitors should be checked before they go in circuit, if you reform them slowly before, they will give a long service life and if you don't, they will heat in circuit and vent their electrolyte as a gas, sometimes two or more hours later depending on how quickly they heat.. So yeah, it's just something to keep in mind, especially if you hoard capacitors like me. And non of them were purchased as new old stock! They were all new modern electrolytic capacitors... The only thing that I really need now is a capacity tester that can read 10,000uF and larger capacity... The testers that I have can't do it, I keep larger values for amplifier power supplies but the cheap testers can't measure it... I guess that I have no choice but to spend more money on something that can... Anyway, great in-depth video. Thank you very much.

Peter.....thank you...I learn so much from your videos. vielen Dank!

Awsome focus with the cam great job.So much info for a newbe like myself. Thank you for your time.

Nice vídeo and description of how caps work, thanks Peter, for another one.

Great video on testing leaky capacitors and related issues. Maintains a good balance between thoroughness and breadth and the necessary practical advice.

Very nice capacitor supplemental video in regards to leakage current testing Peter! I love your methods in testing and explanations. They are very well received and understood by us out here in RU-vid land. Thanks, and very much appreciated 73s Tom

Thanks Peter for a great video about ESR values on capacitors. I do a lot of work on vintage 27mHz CB radio's, and most are ok there is a lot of radio's with Electrolytic Capacitors well out of spec. I don't always Recap a radio unless I find more than 10% of the capacitors out of spec. Then I will do a bulk recap of the radio. I recap'ed a Uniden AX144 with PC833AE board in the set. After the recap, the radio worked like it was brand new. It's build date was February 1983. I been using the radio for 1 year now and it sounds great on air and has great RX as well. The bulk recap was worth the time. I use a ESR meter, capacitance meter and my DVM for current leakage before replacing Electrolytic Capacitors. My rule I work with is back in the 1980's the capacitors were not made as well as they are today, and with the unknown health of these old radio's after 30+ years the caps are going to be stuffed. To get the best out of these radio's a full recap makes sense.

Good explanation and demonstration of leaky caps. Back in the tube days most electronic shops had capacitor analyzers. They were tube type and most had a "magic eye" tube. Most could supply between 500-600VDC for checking leakage current. I did a video a month or so ago on a Semcor (not Sencore) tube type capacitor analyzer. Even old analyzers like that were very accurate if properly calibrated. Mike

Fantastic, go on with your nice mission !!!!Thank you very much.

Thankyou for explaining the new capacitor standard. I guess esr is not as important after all. The most important test is the leakage test under full load and use the current publication from capacitor manufacturer data.

Thanks for sharing. I can see a leakage test as a good test before installing new caps (especially if they have been in your drawer a while). If I remove a capacitor from a old piece of equipment, though, I am apt to just replace it as a matter of course. Most caps are relative cheap, unless you get into the bulk caps on quality old linear power supplies, etc. I think I need one of those DER EE testers first... then later a leakage tester. Thanks again for all your videos. Great channel!

Thanks much Peter. You're the best!

Very nice explanation as always Peter. I can always pick up some good tips from you. Thank you Regards John

Another great video Thank you

Thanks for another great video Peter! You are one of my favorite channels on electronics on RU-vid. 73's de KA2ZOH

great video you and Paul and Buddy are the best never miss one

Thanks so much I learn so much from your video's! You are English is always very easy to listen to and easy to understand!

Thank You for the great video!

Great video Dear Peter... thanks a lot for this excellent efforts.

Thanks Peter for another great tutorial on capacitor leakage. Very well done and great explanation. Also thanks for letting us see all those different capacitor testers you have. nice collection there my friend. I have found that a lot of the cb radios here it is best to replace all caps due to the quality of the ones used. Yes you have to take care in doing so not to cause other faults. One solder bridge can lead to a lot of extra work.. But equipment that uses good grade caps I do not replace all. Only the faulty ones. As always Peter thanks for another great video. 73

A very helpful video, thank you :)

Thanks for the nice lesson, Peter.

I been using many ESR meter for years and I have 3 on the top of my list. GME-236 ESR70 Peak Atlas Dick Smith ESR meter Best Regards.

Hi. which one you think is the best instrument, this or the MSR100 V2.

Thanks for this reference. Subscribed ;)

Very good video. Though these high-voltage DC bench PSUs are not that common. For a 200V type, I'd just use an adjustable transformer, bridge rectifier along with some smoothing and current limiting and call it a "power supply for high voltage capacitor testing".

Great Job Peter. Nice Chart :)

Thanks for all the info.. Appreciated. Could you tell me where I can find a copy of your charts at the end of your video? Thanks in advance.

Great video Peter! I like that little isotest meter. The Sencore is a nice machine as well.

is it possible to measure leakage current in circuit - so without unsoldering it? I know its impossible to measure capacitance...

TNX for yet another great video ! I have the Sencore LC101 and its chart differ from your Sencore. I am glad that the manufacturer are following the one standard now ! 73 N8AUM

Nice one Peter big thumbs up

Peter, do you have the operating manual and/or schematics for the sencore ca55? I can't seem to find them anywhere.

excellent ! Makes a lot of sense to do that testing first.

can capacitance and esr test ok and still fail the leakage test?

peter thanks for all the excellent video clips of your work. i don't repair my own equipment and never will but that doesn't mean I don't enjoy learning. Mike of Mike's radio repair does all my work for me. I have a question for you Peter, what do you think about hf's being used on 11 meters (in the US? I ask because I know that your Clips or at least the ones that I've seen all have to do with hf's being used as they are intended (on amateur bands).

Great video Peter, I tried to build a similar chart with excel but using exponents is a challenge to format. Would you be willing to post you spreadsheet?

Peter...where can I find one of those isotester 6's? you are using?

Hi Peter, Good video indeed. But for High voltage electrolytics, you can use (after checking their caps) units as the Heathkits IT-11 or 28. They are able to test for microamps leakages. 73'S Alain

Excellent video peter. Where did you get the figure on pure cap to equivalent?

Peter aound the 7:00 mark there is a schematic. Is that from the spec sheet?

Really magic! This is German precision!!! Best regards!

Thank you for your capacitor characterization videos. You did an excellent job covering electrolytics. I’m sure you will agree that heat, whether from the operating environment or from ripple current, plays a very significant factor in the degradation of electrolytic capacitors. I was wondering if you have developed a quantitative test procedure for determining capacitor aging? If so, does the test provide a useful estimate of the cap’s EOL? Thanks … D.R.

Hi Very interesting your video. I am interested in acquiring the isotest 6 but i have not found it on the internet. Do you know a link or webpage where i can buy it?. Thank you.

Thanks for the nice explanations you have given us. Finally I was missing the formula ,once again, at the end of the very interesting description and I think it was: factor 0.01x capacitor in microfarad x voltage in volts equals micro current in value as a result of the leakage current?

At 14Min52sec the black strip on the non polarity (old /new stock capacitor) shows which side is the outer plate so that side should be conncted to ground in order to lower noise interference. Not as you name it lower impedance side. This kind capacitors are made of 2 Aluminium foils rolled when connecting the outer side to ground it protects the inner side from being exposed to electromagnetic induction. if outer foil connected to signal path noise level will increase significantly.

you can use a standard multi metre to check for leakage just use amperage setting, capacitors have a CV value

Hi, which meter for testing ESR would be good for me to buy considering I have a very small budget? I noticed in video #81 that you were using the MESR100 but sometimes you have changed to the DE5000. The MESR100 is reasonably priced on Ebay at around $49 while the DE5000 is about $160 with probes. Is one of them better than the other? The MESR100 costs more with the SMD tweezer clip but it is cheap to buy just the clip for only a couple of dollars. I already have a meter that measures capacitance and leakage so I just need one for ESR in circuit using the SMD tweezer clips. Thanks.

Very nice, Peter. Can you post a link to a pdf or jpg of your current chart for max leakage current?

Thanks.

Thanks ! can you share the table you have made maximal eleckstrome fur elkos

The insulation tester that I have at job delivers DC, up to 1000 volt. I'm not familiar with your Isotest model, but it would make sense that it delivers DC as well, which it make it useful even for electrolytic capacitors, in absence of a dedicated tester like Sencore.

Hello Peter, does you know, how the industry tests the leakage of capacitors? 73 aus dem Schwabenland.

Super "cap" info !!! Sub, paw & Thank You ! :-)

Hi Thank for a very useful/interesting video. Much appreciated. Can I point out a small error, 31.34min: You said 63uF instead of 63uA. Best regards Jo

ok I missed it where did you get the chart ? ps great video added you to one I will be following

Nice! When i was building my own capacitor leakage tester i had to determine the NORMAL leakage values, so i searched in books and web. The various equations i found , i put in an excel sheet that can be downloaded here drive.google.com/open?id=0B5klmbaH0rOAUlRHelZzVjRjSEE . Now it seems that the lowest "normal" value for any combination is 3uA, that's why in the datasheet you showed says "...or 3ua whichever is greater..." Also there are time and temperature considerations (5min or 2min) under which the readings are different. It seems that the formula you used is 0.01*C*V The correct one would be (0.01*c*v)+3 for the NORMAL reading IF the voltage is below 100V AND applied for 2min, OR the voltage is above 100V AND apllied for 5min. EN1030300 is the standard that describes the Absolute MAX values, it's formula is ((C*V)^0,7)*0,3)+4 . Hope that helps a bit, download the ecxel sheet an d give it a test. All my measurements so far for good caps fall in the first 2 cases in the sheet and ara much like yours. Thanks for reading this long post! :)

Very good video and also caught the others as well. What I need is your idea having a chart makes it so easy to get that leakage number so seems I am not looking right place for one, could you send me a link to a good one that could use a ref? 73's

I built a simple circuit that will measure leakage current. I test the cap at it rated voltage.

excelent vedio dear

+TRX Bench Could you not measure leakage current with a high-voltage DC PSU and a quality DMM (I prefer the Fluke bench DMMs); even If you don't have a unit with the capabilities of the Sencore CA-55 (many hobbyists won't)? Even my old but still quite accurate Fluke 45 DMM has a DC Current resolution as low as 100nA, on the 10mA range. And, my Fluke 8050a has a resolution of 10nA on the on the 200µA range.

Dear sir, thanks, but can you give us the table? Please?

Hi Peter. This video made me think about to build a simple Leakage tester myself that can test up to ~400V 1st 230v -> ~6V transformer 2nd Voltage multiplier with Steps 6,12,24,48,96,192,384V build with some 2KV Caps and Diodes 3rd Switch between the Steps 4th Some kind of current limiter perhaps a simple 1.5M Resistor 5th An analog 0-250 µA Meter 6th some Button to charge discharge the capacitor and bring down the voltage safely over a discharge Resistor Do you think that would work? 73, DK3JF Jörg

My father repaired radios and amplifiers for 50 years he never had this kind of meters he tested al capacitors on a analoge multimeter or in circuit Never had any problems after repairs so it’s obvious you don’t need al that fancy equipment

Some of them only leak when they are hot ( even still within working temperature ). I hate capacitors lol

I wish I learned this when I was a teen

Yeah but what if we're working on old circuits? Then the old spec should still be good enough.

please turn on english closed captions.

If a capacitor checks out for good ESR, Capacitance and Dissipation, can it still be leaky? When would you suspect leakage is too high?

For detail specifications the machine & PRICE Machine Capacitor Leakage Current- Ir meter Please Contact VALTEKINDO Thank you

Hmm, I thought in fact it is not really the leakage *current* that keeps your electrolytic capaitor healthy but it is the voltage that helps to form and maintain the oxyde film on the aluminium, or am I wrong? I thought, the current would just lead to the electrolyte building up gas pressure.

I love this formula for leakage current in Panasonic capacitors datasheets - left side of inequality is in units of current, right side in units of charge. I know that in electronics it's customary to be sloppy with units, but this " I

I opt for a capacitor tester with real operating voltage. I designed this one (see link), a bit over complicated, but it works very nice. It has a very sensitive current meter. It can do the same as the factory unit in this video. people.zeelandnet.nl/wgeeraert/radio.htm#lektest I also programmed a leakage table in Basic like in the video, export to a CSV file. After some Excel edit: the resulting PDF is over here: pe1abr.homeserver.com/home/pdf/electrolyte_leakage_current_guide__PE1ABR.pdf

Hello none of your links below the video work.

Hey TRXBench. I know almost nothing of electronics. That said, I have a question. I have an ignition box called an M.S.D. ignition box. It is a capacitive discharge ignition box for a car's ignition. When it's running right, it should not have voltage to ignition coil. This box has an led to know it's working right. if the light is bright,there will be no voltage at the coil,and car will start but when the light is dim,there is 425 volts at the coil and will not start this way.If i turn the ign. switch on and off for quite a few times, i might get the light to be bright sometimes. Here is a schematic on page 13 web.tiscalinet.it/giordy/ECU/msd6a_02.pdf . The circuitry is potted. is there an easier way to "discharge"?? the cap,if it is that, so that I get it to work? THANK YOU!!!!!!!

Make that "its" in the title, not "it's".

(y)

I hope that the leakage measuring instrument is discharging the capacitor as the test button is released. Otherwise, it was fun watching the presenter flirting with disaster.

Hello Paul - wow that was some nifty repair. On another matter if I may. I would like to build/purchase from you a kit (if available) for the LV Capacitor Leakage Tester. I would appreciate if you could let me know if its still available. 73 de Ger You can see my contact details on QRZ

Peter, what instrument do you recommend for testing leaky caps?