Old Nichicon Cap Series ID in Ford ECU

[MagicSmoke]

I'm replacing the caps in a ECU for an 88 Ford Ranger.

There are only 2 electrolytics and they are Nichicon, 1 is a 47uf 10v the other is a 3.3uf 63v. Both 8X12mm in size. Bungs on both protruding. No vent relief on top.

There are no series letters on these though just a date code of H8744 and a (M) they have a blue sleeve. Don't know how to figure specs for these, ESR and ripple.

Can anyone recommend a series to use?

Most others on the Ranger forums have been using Radio Crap caps to replace theirs, but I want to use good ones. Thanks.

[stj]

Re: Old Nichicon Cap Series ID in Ford ECU

just use something good with a long life.
like panasonic FR.

[momaka]

Re: Old Nichicon Cap Series ID in Ford ECU

I'm replacing the caps in a ECU for an 88 Ford Ranger.
...
Don't know how to figure specs for these, ESR and ripple.

I don't think low ESR caps existed back in those days. Chances are, those are just standard caps, perhaps rated for long endurance and/or high temperature. I suggest 105C temeperature rating, since the ECU could get quite toasty, depending on where it is located in the car.

Panasonic FR is one good choice - they are rated for 105C and have a long endurance at that temperature. Others are...
Panasonic: FC and FM
Nichicon: HE, PW, HW, PM, PS, PJ, and since you have small caps - PV
United Chemicon: KY, LXV, LXY, and LXZ
Rubycon: YXJ, ZL, ZLJ,
polymers might also work
For the 3.3uF 63V cap, you can also try a film capacitor - but that is only if you have the space as film caps can be rather large.

[stj]

Re: Old Nichicon Cap Series ID in Ford ECU

FC is only 2000hours, FR is around 7000

[Clutchbox]

Re: Old Nichicon Cap Series ID in Ford ECU

FC is only 2000hours, FR is around 7000

I think it is possible that the FC has a longer lifespan than the FR in a car ECU or other automotive application with wide temperature deviations (very cold <> very hot).
Not on the edge of the max. ripplecurrent, but just the longevity in a hars environment:

FC is non-waterbased electrolyte
FR is waterbased electrolyte

FC temp range –55 °C to +105 °C
FR temp range –40 °C to +105 °C

FC has proven it's reliability over many years (15+)
FR is just fairly new, few years (4).

FC is Automotive-grade qualified: AEC-Q200 qualified✽
FR is not applicable for Automotive! as the datasheet warns you.

AEC-Q200: Stress Test Qualification for passive parts
Standards are set to confirm the high reliability of products, including high-temperature/high-humidity resistance, thermal shock resistance, and durability.

So I would choose Panasonic FC for this application to replace the old Nichicon's in the Ford ECU... but I'm not you or the TS and choice is free...
-

✽ This product qualify for AEC-Q200, but it has some deviations.

[Wester547]

Re: Old Nichicon Cap Series ID in Ford ECU

FC is actually rated up to 5,000 hours depending on the case size and FR up to 10,000 hours. FM is the series rated up to 7,000.

I think it is possible that the FC has a longer lifespan than the FR in a car ECU or other automotive application with wide temperature deviations (very cold <> very hot).
Not on the edge of the max. ripplecurrent, but just the longevity in a hars environment:

FC is non-waterbased electrolyte
FR is waterbased electrolyte

FC temp range –55 °C to +105 °C
FR temp range –40 °C to +105 °C

FC has proven it's reliability over many years (15+)

Those older Nichicon PF and PR capacitors found in ECUs had a range of -55C to +105C as well but they still leaked somewhat prematurely (10-15 years, sometimes 20 years or more). Those were said to have had defective electrolyte ("quaternary ammonium salts compounds" - electrolyte capable of withstanding temperatures as low as -55C unlike some other solvents used in other GP capacitors). That being said, I've seen PF and PR do fine in very old electronics (from the 80s), so I think the aforementioned temperature deviations (which were quite fast at that) had something to do with it. PR is actually a general purpose series, too (the "large" version of VZ). PF is technically "low ESR", though (but certainly not by any recent standards), as can be told by the 100KHz ripple ratings as compared to the 120Hz ones in GP capacitors (PF is from the late 80s, I believe, and the impedance values are listed in the datasheet). Non-aqueous electrolyte still uses a form of liquid or organic solvent in electrolytic capacitors, but it dries up much slower and is more stable than water base electrolyte. However, they still dry up much faster than the solid electrolyte found in polymers (duh!).

FR is just fairly new, few years (4).

I doubt FR is unreliable. It's probably built with a strong and thick dielectric and has the proper additives, oxidizers, and neutralizers to passivate the water base electrolyte's habit of thinning the dielectric until some weak spot breaks down and hydrogen and gas forms (and even those neutralizers have a wear out mechanism). The issue with water base electrolyte found in ultra low ESR capacitors isn't just the fact that it expands with heat as well as cold and that it's somewhat unstable, it's the fact that ultra low ESR capacitors tend to have much more of that kind of electrolyte and a thinner dielectric (hence the fact that they often only go up to 16V and only are rated for 2,000 hours, though that may have to do with the fact that they are designed for motherboards as well... the dielectric thickens as ESR and voltage increases/capacitance decreases and thins as ESR and voltage decreases/capacitance increases) which makes the problem of attacking the electrolyte much worse, especially when the dielectric degrades on the shelf. And the warning against using FR in automobiles is a good catch so FC is probably a better choice, at length, but if you just want a quick replacement for the failed Nichicons the FR may work.

[MagicSmoke]

Re: Old Nichicon Cap Series ID in Ford ECU

Thanks for the info. They are both output filter caps for 2 different transistors so I was unsure how critical ESR and ripple needed to be. The ECU is inside pass. compartment so it doesn't see underhood temps.

I'll order up some FC's and see if it fixes my problem. Thanks again.

[stj]

Re: Old Nichicon Cap Series ID in Ford ECU

ripple will depend on the load - if it's switching a solenoid then you need good ripple.

esr depends on the frequency, if it's part of a dc-dc convertor then you need low esr - if it's just smoothing a switch then you dont.

[momaka]

Re: Old Nichicon Cap Series ID in Ford ECU

Probably not part of DC-DC converter, as that usually requires fairly large capacitance and both input and output capacitors.
For the 3.3 uF cap, I still wonder how well (or not?) a film cap will perform.

By the way, Nichicon PW and United Chemicon LXV, LXY, and LXZ also have non-aqueous electrolyte and more or less equivalent to Panasonic FC.

[PeteS in CA]

Re: Old Nichicon Cap Series ID in Ford ECU

I'd go with Nichicon PW series or UCC LXZ series, which are approximate equivalents. Fairly low impedance, fairly high ripple current rating, long rated life.

Back in the early 80s ...

Nichicon's low ESR series were the PA and PB (dark green sleeves, IIRC).

UCC's low ESR series were the RX and RX (yellow-orange sleeves).

Sprague's low ESR series were the 672D, 673D, and 674D (clear sleeves).

And they were called "Low ESR", not "Low Impedance". I'm guessing ESL was less relevant with switch frequencies in the 20KHz-30KHz range.

[BLIND.NEED.CAPS]

Re: Old Nichicon Cap Series ID in Ford ECU

HELLO THERE, I SAW YOU POST ON THE CAPS ON YOUR 88 RANGER EEC AND I
WAS WONDERING IF YOU CAN TELL ME WHAT POSITION THE 4.7uf-10V GOES IN ALSO WHAT POSITION THE 3.3uf-63V ALSO WHAT HOLE THE NEGITIVE TERMINAL ON BOTH
OF THEM GO IN. MY GRANSON TOOK THE OLD ONES OUT AND DIDN'T PAY ATTENTION
TO WITCH GOES WEAR. THANKS IN ADVANCE IF YOU CAN REMEMBER I DON'T KNOW OLD THIS POST IS HERE. YOU CAN E-MAIL ME @ BLIND.NEED.CAPS@GMAIL.COM
MY NAME IS FRANK