Microelectronics | Electrolytic Capacitors Characterization

Synopsis

Over the last six years I have collected a small box of spare electrolytic capacitors of various series, all made by Nichicon. While a few of them are made in Japan, the rest are made in Malaysia. At least that is the information that I have from Mouser.

I was curious about how these new capacitors measure up against old ones. So I found some spare time and decided to start collecting some scientific data. I have to mention these capacitors have date codes between 2016 and 2021. Some of them have already exceeded their guaranteed five years shelf life -- which shouldn't be an issue for me to use them in future projects.

An interesting fact is that I couldn't find any official ESR rating published in any of the Nichicon electrolytic capacitor series datasheets that I inspected.

Disclaimer: Let's get this straight from the start. I am in no way affiliated with Nichicon, nor do I gain anything from them for this article. As a matter of fact I don't care at all about recommending Nichicon or any other brand of capacitor. Nichicon is just another brand of quality electrolytic capacitors. Just like Nippon Chemi-Con, Panasonic, ELNA, Kemet, Vishay, and the like. Do your own research and choose what's best for you, but please don't choose cheap failure prone capacitors.

Essay

For this essay I will use the freshly restored and aligned Hewlett-Packard 4276A LCZ Meter.

One mention though. This unit is not production ready. So my measurements can all be considered informative. In order to have production certified measurements, the LCZ meter would need a calibration with reference capacitors and reference resistors. Which I don't have and nor do I plan to officially calibrate my LCZ meter. I'm a hobbyist and for my needs this unit is already fulfilling the job requirements.

But to be safe, before starting the measurements, I let the unit warm up for half an hour or so. Then I repeatedly took measurements of the same capacitor for a couple of minutes to make sure the results are concludent.

I have measured all electrolytic capacitors at 120 Hz, with the DC-bias function off. Also the speed of measurement was set to slow in order to get the best results. Extra care must be taken while observing the reading on DISPLAY B as due to auto-ranging mechanism, the measurements will be reported either in Ω or in kΩ. In case of kΩ values, I just turned off the auto-range circuit and switched DISPLAY B to Ω instead. Well for measuring similar capacitors, I ended up switching off the auto-range function completely.

I am hoping to bust some electrolytic capacitor myths and also strengthen my knowledge in this field. Based on this, I will do better capacitor selections for my projects, either vintage audio repairs or test equipment restorations.

As a side note, by the time you read this article, I might have already added more capacitor data besides the initial batch of 85 samples that I measured.

Research

Collecting data was fun. I went with the old way of doing things. Thus the steps were to first insert a capacitor in the fixture, inspect the reading on the instrument displays, and finally note the results in a tabular format on paper. I haven't even realized when time passed by and I filled three pages of measurements.

Sorting this data on paper is difficult. I decided to transfer everything on the computer so that I can easily classify the measurements I took based on capacitor series. Hence the idea for writing this article was instantly born.

I haven't paid close attention to DISPLAY B and (mechanically) noted down every ESR value as if they were measured directly in Ω, even if in a few cases the display was reading in kΩ due to auto-range being turned on. I had to retake a few selected measurements and correct the data on the fly while I typed-in the values in this article. Thus all research data in the tables below represent the correct ESR values, measured in Ω. For instance the incorrect value on paper of 0.010 Ω actually means 0.010 kΩ which translates to around 10 Ω. That's it, no more beer while measuring capacitors -- ha ha.

Here we go with Nichicon BT series. These are the capacitors that I always chose for all power supply new designs, repair and/or restore.

NICHICON BT SERIES CAPACITOR DATA
BRANDTYPESTYLERATINGCAPACITYESR
NichiconElectrolyticRadial10 uF / 100 V10.38 uF2.95 Ω
NichiconElectrolyticRadial10 uF / 100 V10.49 uF2.94 Ω
NichiconElectrolyticRadial10 uF / 50 V10.09 uF2.42 Ω
NichiconElectrolyticRadial10 uF / 50 V10.14 uF2.55 Ω
NichiconElectrolyticRadial4.7 uF / 50 V4.78 uF2.52 Ω
NichiconElectrolyticRadial4.7 uF / 50 V4.80 uF2.66 Ω
NichiconElectrolyticRadial4.7 uF / 50 V4.76 uF2.59 Ω

Next up is the Nichicon PW series. I am using these mainly for power supply purposes, especially if there is a switching-mode power conversion design. I am using them for either filtering, reservoir, decoupling, and as a general purpose capacitor.

NICHICON PW SERIES CAPACITOR DATA
BRANDTYPESTYLERATINGCAPACITYESR
NichiconElectrolyticRadial220 uF / 16 V209 uF2.40 Ω
NichiconElectrolyticRadial47 uF / 25 V41.75 uF2.31 Ω
NichiconElectrolyticRadial22 uF / 50 V20.99 uF2.21 Ω
NichiconElectrolyticRadial22 uF / 50 V20.75 uF2.34 Ω
NichiconElectrolyticRadial22 uF / 50 V20.84 uF2.21 Ω
NichiconElectrolyticRadial22 uF / 50 V20.63 uF2.43 Ω
NichiconElectrolyticRadial22 uF / 50 V20.71 uF2.41 Ω
NichiconElectrolyticRadial2.2 uF / 50 V2.38 uF21.0 Ω

Here we go with Nichicon KL series. I rarely use these kind of capacitors but in places where really low leakage parts are required, they really come in handy. Think magnetic head preamplifier first stage coupling, for instance.

NICHICON KL SERIES CAPACITOR DATA
BRANDTYPESTYLERATINGCAPACITYESR
NichiconElectrolyticRadial47 uF / 25 V45.60 uF1.19 Ω
NichiconElectrolyticRadial47 uF / 25 V45.60 uF1.22 Ω
NichiconElectrolyticRadial47 uF / 25 V46.30 uF1.14 Ω
NichiconElectrolyticRadial47 uF / 25 V45.90 uF1.23 Ω

Let's measure the Nichicon ES series capacitors for now. These are my all time favorites for audio signal coupling betweens successive stages and also for negative feedback networks.

NICHICON ES MUSE SERIES CAPACITOR DATA
BRANDTYPESTYLERATINGCAPACITYESR
NichiconElectrolyticRadial220 uF / 16 V229 uF0.23 Ω
NichiconElectrolyticRadial220 uF / 16 V229 uF0.21 Ω
NichiconElectrolyticRadial47 uF / 16 V46.90 uF1.38 Ω
NichiconElectrolyticRadial47 uF / 16 V47.10 uF1.38 Ω
NichiconElectrolyticRadial4.7 uF / 50 V4.71 uF14.8 Ω
NichiconElectrolyticRadial4.7 uF / 50 V4.46 uF15.1 Ω
NichiconElectrolyticRadial4.7 uF / 50 V4.60 uF14.0 Ω
NichiconElectrolyticRadial4.7 uF / 50 V4.78 uF14.1 Ω
NichiconElectrolyticRadial3.3 uF / 50 V3.43 uF19.9 Ω
NichiconElectrolyticRadial3.3 uF / 50 V3.49 uF19.8 Ω
NichiconElectrolyticRadial3.3 uF / 50 V3.43 uF19.9 Ω
NichiconElectrolyticRadial3.3 uF / 50 V3.44 uF19.7 Ω

Let's check the Nichicon FG series. I am using these as all purpose capacitors for audio circuits, either vintage audio repair or new designs.

NICHICON FG SERIES CAPACITOR DATA
BRANDTYPESTYLERATINGCAPACITYESR
NichiconElectrolyticRadial470 uF / 16 V438 uF0.21 Ω
NichiconElectrolyticRadial470 uF / 16 V434 uF0.23 Ω
NichiconElectrolyticRadial220 uF / 35 V205 uF0.27 Ω
NichiconElectrolyticRadial220 uF / 35 V206 uF0.25 Ω
NichiconElectrolyticRadial220 uF / 25 V209 uF0.24 Ω
NichiconElectrolyticRadial220 uF / 16 V184 uF0.35 Ω
NichiconElectrolyticRadial220 uF / 16 V187 uF0.35 Ω
NichiconElectrolyticRadial220 uF / 16 V185 uF0.35 Ω
NichiconElectrolyticRadial220 uF / 16 V181 uF0.35 Ω
NichiconElectrolyticRadial100 uF / 25 V90.1 uF0.61 Ω
NichiconElectrolyticRadial100 uF / 16 V93.0 uF0.72 Ω
NichiconElectrolyticRadial47 uF / 25 V42.35 uF1.82 Ω
NichiconElectrolyticRadial47 uF / 25 V42.34 uF1.84 Ω
NichiconElectrolyticRadial47 uF / 25 V42.10 uF1.82 Ω
NichiconElectrolyticRadial47 uF / 25 V42.10 uF1.81 Ω
NichiconElectrolyticRadial47 uF / 25 V42.81 uF1.72 Ω
NichiconElectrolyticRadial47 uF / 25 V42.79 uF1.79 Ω
NichiconElectrolyticRadial47 uF / 25 V42.73 uF1.81 Ω
NichiconElectrolyticRadial47 uF / 25 V42.23 uF1.78 Ω
NichiconElectrolyticRadial33 uF / 16 V27.62 uF3.95 Ω
NichiconElectrolyticRadial33 uF / 16 V27.43 uF3.90 Ω
NichiconElectrolyticRadial33 uF / 16 V27.66 uF4.02 Ω
NichiconElectrolyticRadial33 uF / 16 V26.93 uF4.00 Ω
NichiconElectrolyticRadial10 uF / 50 V9.22 uF5.10 Ω
NichiconElectrolyticRadial10 uF / 50 V8.71 uF6.15 Ω
NichiconElectrolyticRadial10 uF / 50 V9.03 uF5.12 Ω
NichiconElectrolyticRadial10 uF / 50 V8.90 uF6.05 Ω
NichiconElectrolyticRadial4.7 uF / 50 V4.84 uF10.8 Ω
NichiconElectrolyticRadial3.3 uF / 50 V3.38 uF7.16 Ω
NichiconElectrolyticRadial3.3 uF / 50 V3.38 uF8.20 Ω
NichiconElectrolyticRadial2.2 uF / 50 V2.23 uF10.1 Ω
NichiconElectrolyticRadial2.2 uF / 50 V2.22 uF10.3 Ω

Now let's switch to the Nichicon KZ MUSE series. I prefer these for vintage audio power supply ripple filtering, decoupling, signal pass-through, and as a general purpose capacitor.

NICHICON KZ MUSE SERIES CAPACITOR DATA
BRANDTYPESTYLERATINGCAPACITYESR
NichiconElectrolyticRadial220 uF / 25 V200 uF0.22 Ω
NichiconElectrolyticRadial22 uF / 50 V20.15 uF2.28 Ω
NichiconElectrolyticRadial22 uF / 50 V21.45 uF2.17 Ω
NichiconElectrolyticRadial22 uF / 50 V20.44 uF2.29 Ω
NichiconElectrolyticRadial22 uF / 50 V20.91 uF2.38 Ω
NichiconElectrolyticRadial22 uF / 50 V20.78 uF2.25 Ω
NichiconElectrolyticRadial22 uF / 50 V19.83 uF2.36 Ω
NichiconElectrolyticRadial22 uF / 50 V20.57 uF2.38 Ω
NichiconElectrolyticRadial22 uF / 50 V20.51 uF2.50 Ω
NichiconElectrolyticRadial22 uF / 50 V20.81 uF2.33 Ω
NichiconElectrolyticRadial22 uF / 50 V20.75 uF2.30 Ω
NichiconElectrolyticRadial22 uF / 50 V19.99 uF2.27 Ω
NichiconElectrolyticRadial22 uF / 50 V20.75 uF2.38 Ω
NichiconElectrolyticRadial22 uF / 50 V20.57 uF2.45 Ω
NichiconElectrolyticRadial22 uF / 50 V21.02 uF2.35 Ω
NichiconElectrolyticRadial22 uF / 50 V20.55 uF2.38 Ω
NichiconElectrolyticRadial10 uF / 100 V9.44 uF4.34 Ω
NichiconElectrolyticRadial10 uF / 100 V9.87 uF4.27 Ω
NichiconElectrolyticRadial10 uF / 100 V9.54 uF4.18 Ω
NichiconElectrolyticRadial10 uF / 100 V9.30 uF3.29 Ω
NichiconElectrolyticRadial10 uF / 100 V8.96 uF3.32 Ω
NichiconElectrolyticRadial10 uF / 100 V9.61 uF3.45 Ω

I gathered quite some data that reveals an overview on the capacities and ESRs of the various Nichicon series aluminum electrolytic capacitors.

Conclusions

One interesting fact is that most capacitors have an actual lower capacitance rating than what they are marketed. If a circuit prompts for a very specific rating of capacitor, than it's best to know that most of them are underrated and cannot be used in circuit sections where precision is required. However for most audio and general purposes, the capacitors above are all very good candidates.

I am especially puzzled by the various 220 uF capacitors. In some cases their actual capacity is like 35 uF less than what they are officially rated. Normally the capacitance tolerance for electrolytic capacitors is between - 20 % to + 70 % of their rated capacity. 180 uF is still within tolerance. But I wasn't expecting such low values. I think this all comes out of materials economy on the production line.

Also, the lower the capacitance (and the lower the maximum operating voltage) the higher the ESR is. That is why I prefer film capacitors for circuits designed for capacitors rated 4.7 uF or less. The high ESR is revealed especially while looking at the ES series which are bipolar capacitors constructed from two standard polarized capacitors with both positive terminals connected toghether to form a series connection. I think it's quite normal to see ESRs in the 15 Ω range since the individual resistance of both series capacitors sums up. But the unexpectedly high ESR of 21 Ω on the 2.2 uF Nichicon PW series capacitor is probably their recipe to "dampen" oscillations in SMPS designs. However this assumption might totally be off since I don't have any information in this direction. Anyway, low capacitance PW series have high ESR values.

This was a fun research that shed some light on current production electrolytic capacitors of various series produced by Nichicon. This whole documentation will better help me chose capacitors for my projects. I hope you find it useful as well.

Your Help Matters

This essay is provided as-is and is not for commercial purposes. It reflects my experiments and research and should be treated as such. I release my work to the public for educational purposes. I did all this on my expense and in my free time. So if you like my work, or find it useful or inspiring for your projects, please consider a donation.


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