200 amp flier ,caps get hot,

[Speedfreek]

Yes

ok just for argument sake why not parallel?

[Prodrvr]

ok just for argument sake why not parallel?

Did I give the wrong answer? It's supposed to be wired in parallel.

[Speedfreek]

Did I give the wrong answer? It's supposed to be wired in parallel.

ok

[Prodrvr]

I would make up a cap bank of a lot of smaller caps over a few large caps.

[Speedfreek]

I would make up a cap bank of a lot of smaller caps over a few large caps.

Ok, what would you recommend for a 8S set up 2x/4S per side 2x ESC about 360 Amp draw motor TP 5850 1400kv ?
I have 16x ZLH 63V 1200UF and 20x ZLH 50V 820UF caps.
Sorry for the hijack

[Prodrvr]

The ZLH 820 caps...10 of them to make a pack. I happened to just get in the ZLH 820 63v caps that I gotta get soldering on.

[Speedfreek]

[CraigP]

Are you saying parallel or series?

[ATTACH=CONFIG]161042[/ATTACH] like this or

[ATTACH=CONFIG]161043[/ATTACH] like this

Both of these schematics are series-parallel combination. It’s used on high volt, 10s and higher. Most usually just wire all caps in parallel.

[Speedfreek]

Both of these schematics are series-parallel combination. It’s used on high volt, 10s and higher. Most usually just wire all caps in parallel.

Thanks Craig so like this for up to 8S
20180118_152648.jpg

[CraigP]

That looks like a good cap Bank! Make sure you use a good quality cap. If you search for cap banks on the site, I have given part numbers and vendor to get good ones. The one I listed is for 8s... if I recall correctly, it’s 3600uF at 50V with the highest rated ripple current and temp I could find. Spent some time on this... Hang on, I think I got a bag of them, yes, found it! Here’s the info:

Vendor: Mouser.com
P/N: EGPD500ELL362MM40H

Mouser has a spec sheet if you want to learn about that... I use 3 in parallel for 8s to 150A average current. Use 5 for 200A.

[Prodrvr]

I thought having more of a smaller uF cap is better than just a few very large uF caps?

[CraigP]

It depends on the quality and the ripple current rating. A bunch of lower quality caps is not as good as fewer high quality caps. Three of the caps I listed will decouple 50A of ripple current. Don’t confuse ripple current magnitude with motor current. What you are decoupling is the wire power feeds (inductance) and the resistance of wire, solder joints and connectors.

If your getting ‘just any cap’ at your local surplus shop, then you really don’t know what you’re putting in there. Also, keep in mind, electrolytic caps dry out over time, so I would never buy a surplus cap for any of these boats! This is an extremely harsh electrical demand on the caps! You need to respect that highly...

[Prodrvr]

I just got 10 Rubycon ZLH 820uF 63v caps that I was just gonna solder up. Are the ones you listed better? If so, I'll order a bunch.

[Prodrvr]

But are 50v caps good for 12s?

[CraigP]

I just got 10 Rubycon ZLH 820uF 63v caps that I was just gonna solder up. Are the ones you listed better? If so, I'll order a bunch.

The Rubycon cap has 5 times higher impedance! Just looked it up on Digi-Key site. It would take 5 of those caps to equal just one of the caps I referenced... BTW, Rubycon has a low quality reputation, made for high volume, general purpose input rectifier circuits...