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, China, or other Asian countries. 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 or any brand presented in this article, nor do I gain anything from them for writing this essay. 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 ELNA, Kemet, Nippon Chemi-Con, Panasonic, Rubycon, 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. Thus, 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. Anyway, the HP 4276A unit takes far better measurements than any other cheap microcontroller-based DIY capacitance meter.

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 the auto-ranging mechanism, the measurements will be reported either in Ω or in kΩ. In the case of kΩ values, I just turned off the auto-range circuit and switched DISPLAY B to Ω instead. Finally, to measure 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.

Later edit: By the time you read this article, I have already added more capacitor data besides the batch of 85 Nichicon samples that I initially measured. I initially measured only Nichicon capacitors, but in the meantime, I expanded the measurements database with other brands.

Research

Collecting data was fun as 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 didn't even realize that time passed by, and I filled out three pages of measurements.

Sorting this data on paper is difficult. I decided to transfer everything to the computer so that I could easily classify the measurements I took based on the 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.

I lately measured some Chemi-Con KY capacitors, and here are the results. I tend to use these in power supply circuits.

CHEMI-CON KY SERIES CAPACITOR DATA
Brand	Type	Style	Rating	Capacity	ESR
Chemi-Con	Electrolytic	Radial	3300 uF / 10 V	3530 uF	0.03 Ω
Chemi-Con	Electrolytic	Radial	3300 uF / 10 V	3528 uF	0.03 Ω
Chemi-Con	Electrolytic	Radial	2700 uF / 16 V	2584 uF	0.03 Ω
Chemi-Con	Electrolytic	Radial	2700 uF / 16 V	2593 uF	0.03 Ω
Chemi-Con	Electrolytic	Radial	2200 uF / 16 V	2209 uF	0.04 Ω
Chemi-Con	Electrolytic	Radial	2200 uF / 16 V	2214 uF	0.04 Ω

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

NICHICON BT SERIES CAPACITOR DATA
Brand	Type	Style	Rating	Capacity	ESR
Nichicon	Electrolytic	Radial	22 uF / 350 V	22.92 uF	1.69 Ω
Nichicon	Electrolytic	Radial	22 uF / 350 V	22.73 uF	1.71 Ω
Nichicon	Electrolytic	Radial	10 uF / 100 V	10.38 uF	2.95 Ω
Nichicon	Electrolytic	Radial	10 uF / 100 V	10.49 uF	2.94 Ω
Nichicon	Electrolytic	Radial	10 uF / 50 V	10.09 uF	2.42 Ω
Nichicon	Electrolytic	Radial	10 uF / 50 V	10.14 uF	2.55 Ω
Nichicon	Electrolytic	Radial	4.7 uF / 50 V	4.78 uF	2.52 Ω
Nichicon	Electrolytic	Radial	4.7 uF / 50 V	4.80 uF	2.66 Ω
Nichicon	Electrolytic	Radial	4.7 uF / 50 V	4.76 uF	2.59 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
Brand	Type	Style	Rating	Capacity	ESR
Nichicon	Electrolytic	Radial	470 uF / 250 V	405 uF	0.15 Ω
Nichicon	Electrolytic	Radial	470 uF / 250 V	419 uF	0.14 Ω
Nichicon	Electrolytic	Radial	470 uF / 160 V	433 uF	0.08 Ω
Nichicon	Electrolytic	Radial	2200 uF / 35 V	2129 uF	0.04 Ω
Nichicon	Electrolytic	Radial	220 uF / 16 V	209 uF	2.40 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	41.75 uF	2.31 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.99 uF	2.21 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.75 uF	2.34 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.84 uF	2.21 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.63 uF	2.43 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.71 uF	2.41 Ω
Nichicon	Electrolytic	Radial	2.2 uF / 50 V	2.38 uF	21.00 Ω

Now, switching to the Nichicon KL series. I rarely use these kinds 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
Brand	Type	Style	Rating	Capacity	ESR
Nichicon	Electrolytic	Radial	47 uF / 25 V	45.60 uF	1.19 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	45.60 uF	1.22 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	46.30 uF	1.14 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	45.90 uF	1.23 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
Brand	Type	Style	Rating	Capacity	ESR
Nichicon	Electrolytic	Radial	470 uF / 16 V	462 uF	0.07 Ω
Nichicon	Electrolytic	Radial	220 uF / 16 V	229 uF	0.23 Ω
Nichicon	Electrolytic	Radial	220 uF / 16 V	229 uF	0.21 Ω
Nichicon	Electrolytic	Radial	47 uF / 16 V	46.90 uF	1.38 Ω
Nichicon	Electrolytic	Radial	47 uF / 16 V	47.10 uF	1.38 Ω
Nichicon	Electrolytic	Radial	4.7 uF / 50 V	4.71 uF	14.80 Ω
Nichicon	Electrolytic	Radial	4.7 uF / 50 V	4.46 uF	15.10 Ω
Nichicon	Electrolytic	Radial	4.7 uF / 50 V	4.60 uF	14.00 Ω
Nichicon	Electrolytic	Radial	4.7 uF / 50 V	4.78 uF	14.10 Ω
Nichicon	Electrolytic	Radial	3.3 uF / 50 V	3.43 uF	19.90 Ω
Nichicon	Electrolytic	Radial	3.3 uF / 50 V	3.49 uF	19.80 Ω
Nichicon	Electrolytic	Radial	3.3 uF / 50 V	3.43 uF	19.90 Ω
Nichicon	Electrolytic	Radial	3.3 uF / 50 V	3.44 uF	19.70 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
Brand	Type	Style	Rating	Capacity	ESR
Nichicon	Electrolytic	Radial	470 uF / 16 V	438 uF	0.21 Ω
Nichicon	Electrolytic	Radial	470 uF / 16 V	434 uF	0.23 Ω
Nichicon	Electrolytic	Radial	220 uF / 35 V	205 uF	0.27 Ω
Nichicon	Electrolytic	Radial	220 uF / 35 V	206 uF	0.25 Ω
Nichicon	Electrolytic	Radial	220 uF / 25 V	209 uF	0.24 Ω
Nichicon	Electrolytic	Radial	220 uF / 16 V	184 uF	0.35 Ω
Nichicon	Electrolytic	Radial	220 uF / 16 V	187 uF	0.35 Ω
Nichicon	Electrolytic	Radial	220 uF / 16 V	185 uF	0.35 Ω
Nichicon	Electrolytic	Radial	220 uF / 16 V	181 uF	0.35 Ω
Nichicon	Electrolytic	Radial	100 uF / 25 V	90.1 uF	0.61 Ω
Nichicon	Electrolytic	Radial	100 uF / 16 V	93.0 uF	0.72 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	42.35 uF	1.82 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	42.34 uF	1.84 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	42.10 uF	1.82 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	42.10 uF	1.81 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	42.81 uF	1.72 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	42.79 uF	1.79 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	42.73 uF	1.81 Ω
Nichicon	Electrolytic	Radial	47 uF / 25 V	42.23 uF	1.78 Ω
Nichicon	Electrolytic	Radial	33 uF / 16 V	27.62 uF	3.95 Ω
Nichicon	Electrolytic	Radial	33 uF / 16 V	27.43 uF	3.90 Ω
Nichicon	Electrolytic	Radial	33 uF / 16 V	27.66 uF	4.02 Ω
Nichicon	Electrolytic	Radial	33 uF / 16 V	26.93 uF	4.00 Ω
Nichicon	Electrolytic	Radial	10 uF / 50 V	9.22 uF	5.10 Ω
Nichicon	Electrolytic	Radial	10 uF / 50 V	8.71 uF	6.15 Ω
Nichicon	Electrolytic	Radial	10 uF / 50 V	9.03 uF	5.12 Ω
Nichicon	Electrolytic	Radial	10 uF / 50 V	8.90 uF	6.05 Ω
Nichicon	Electrolytic	Radial	4.7 uF / 50 V	4.84 uF	10.80 Ω
Nichicon	Electrolytic	Radial	3.3 uF / 50 V	3.38 uF	7.16 Ω
Nichicon	Electrolytic	Radial	3.3 uF / 50 V	3.38 uF	8.20 Ω
Nichicon	Electrolytic	Radial	2.2 uF / 50 V	2.23 uF	10.10 Ω
Nichicon	Electrolytic	Radial	2.2 uF / 50 V	2.22 uF	10.30 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
Brand	Type	Style	Rating	Capacity	ESR
Nichicon	Electrolytic	Radial	220 uF / 25 V	200 uF	0.22 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.15 uF	2.28 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	21.45 uF	2.17 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.44 uF	2.29 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.91 uF	2.38 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.78 uF	2.25 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	19.83 uF	2.36 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.57 uF	2.38 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.51 uF	2.50 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.81 uF	2.33 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.75 uF	2.30 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	19.99 uF	2.27 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.75 uF	2.38 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.57 uF	2.45 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	21.02 uF	2.35 Ω
Nichicon	Electrolytic	Radial	22 uF / 50 V	20.55 uF	2.38 Ω
Nichicon	Electrolytic	Radial	10 uF / 100 V	9.44 uF	4.34 Ω
Nichicon	Electrolytic	Radial	10 uF / 100 V	9.87 uF	4.27 Ω
Nichicon	Electrolytic	Radial	10 uF / 100 V	9.54 uF	4.18 Ω
Nichicon	Electrolytic	Radial	10 uF / 100 V	9.30 uF	3.29 Ω
Nichicon	Electrolytic	Radial	10 uF / 100 V	8.96 uF	3.32 Ω
Nichicon	Electrolytic	Radial	10 uF / 100 V	9.61 uF	3.45 Ω

I also use Vishay capacitors, mostly with audio-related projects. They still offer a good selection of axial capacitors. Let's make an idea about their specifications.

Vishay offers miniaturized high temperature, high ripple current axial electrolytic capacitors as part of the 126 ALX series. These are advertised as having an extra long useful life of up to 8000 hours at 125 °C.

VISHAY 120 ALX SERIES CAPACITOR DATA
Brand	Type	Style	Rating	Capacity	ESR
Vishay	Electrolytic	Axial	1000 uF / 63 V	954 uF	0.06 Ω
Vishay	Electrolytic	Axial	1000 uF / 63 V	935 uF	0.06 Ω

Vishay 120 ATC capacitors are axial hight temperature, high ripple curent for use up to 150 °C.

VISHAY 120 ATC SERIES CAPACITOR DATA
Brand	Type	Style	Rating	Capacity	ESR
Vishay	Electrolytic	Axial	2200 uF / 16 V	1992 uF	0.04 Ω

The 118 AHT series features extra long life at 125 °C and high reliability.

VISHAY 118 AHT SERIES CAPACITOR DATA
Brand	Type	Style	Rating	Capacity	ESR
Vishay	Electrolytic	Axial	2200 uF / 63 V	2130 uF	0.04 Ω

I wanted to test some other non-Japanese capacitors (well, most Japanese capacitors are now made in China or Malaysia, or other countries). I bought some Würth Elektronik capacitors for a COMPAQ Prolinea 4/66 power supply. In the meantime, I bought some more for non-critical repairs.

The ATG5 series are general purpose capacitors, operating at a maximum temperature of 105 °C.

WÜRTH ELEKTRONIK WCAP-ATG5 SERIES CAPACITOR DATA
Brand	Type	Style	Rating	Capacity	ESR
Würth Elektronik	Electrolytic	Radial	2200 uF / 10 V	2065 uF	0.07 Ω
Würth Elektronik	Electrolytic	Radial	1500 uF / 35 V	1392 uF	0.07 Ω
Würth Elektronik	Electrolytic	Radial	1500 uF / 35 V	1392 uF	0.06 Ω
Würth Elektronik	Electrolytic	Radial	1000 uF / 35 V	911 uF	0.09 Ω
Würth Elektronik	Electrolytic	Radial	1000 uF / 35 V	911 uF	0.09 Ω
Würth Elektronik	Electrolytic	Radial	1000 uF / 25 V	873 uF	0.12 Ω
Würth Elektronik	Electrolytic	Radial	1000 uF / 25 V	876 uF	0.12 Ω
Würth Elektronik	Electrolytic	Radial	68 uF / 63 V	63 uF	0.62 Ω

The AT1H capacitors are long life, whitstanding a maximum temperature of 105 °C.

WÜRTH ELEKTRONIK WCAP-AT1H SERIES CAPACITOR DATA
Brand	Type	Style	Rating	Capacity	ESR
Würth Elektronik	Electrolytic	Radial	22 uF / 50 V	22.04 uF	2.71 Ω

The ATLI series includes low impedance electrolytic capacitors with a maximum operating temperature of 105 °C.

WÜRTH ELEKTRONIK WCAP-ATLI SERIES CAPACITOR DATA
Brand	Type	Style	Rating	Capacity	ESR
Würth Elektronik	Electrolytic	Radial	820 uF / 25 V	765 uF	0.05 Ω

The ATUL series designates low-leakage and long life capacitors, with a temperature rating of 105 °C.

WÜRTH ELEKTRONIK WCAP-ATUL SERIES CAPACITOR DATA
Brand	Type	Style	Rating	Capacity	ESR
Würth Elektronik	Electrolytic	Radial	100 uF / 16 V	105 uF	0.40 Ω
Würth Elektronik	Electrolytic	Radial	47 uF / 50 V	44.8 uF	0.83 Ω
Würth Elektronik	Electrolytic	Radial	47 uF / 50 V	46.8 uF	1.05 Ω
Würth Elektronik	Electrolytic	Radial	47 uF / 50 V	46.0 uF	1.04 Ω
Würth Elektronik	Electrolytic	Radial	47 uF / 50 V	46.0 uF	0.84 Ω

The ATLL series designates long life capacitors, rated up to 105 °C.

WÜRTH ELEKTRONIK WCAP-ATLL SERIES CAPACITOR DATA
Brand	Type	Style	Rating	Capacity	ESR
Würth Elektronik	Electrolytic	Radial	10 uF / 50 V	9.6 uF	9.20 Ω
Würth Elektronik	Electrolytic	Radial	4.7 uF / 50 V	4.49 uF	8.83 Ω
Würth Elektronik	Electrolytic	Radial	4.7 uF / 50 V	4.61 uF	8.96 Ω
Würth Elektronik	Electrolytic	Radial	4.7 uF / 50 V	4.58 uF	10.18 Ω

From the initial measurements, the ESR values of the Würth Elektronik capacitors are on par with their Nichicon counterparts. We'll see how they hold in time.

In the end, I gathered quite a lot of data, revealing an overview of the capacitances and ESRs of the various aluminum electrolytic capacitors that I use in my projects.

Conclusions

One interesting fact is that most capacitors actually have a lower capacitance rating than advertised. If a circuit prompts for a very specific rating of capacitor, then 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 the prime 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 fun research that shed some light on current production electrolytic capacitors of various series produced by Nichicon, and not only. This whole documentation will help me better choose 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 at my own expense and in my free time. So if you like my work, or find it useful or inspiring for your projects, please consider making a donation.

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