Running an ESC with a blown Capacitor.

[Hardcore]

I've a Hobbywing ESC, with a built in capacitor.
I had a bad bump in my truck the other day and for one reason or another, after the bad bump, i heard a loud and short "hiss" like a tyre going down rapid.

On inspection, the capacitor on the ESC had swollen slightly at the top (bevelled outwards, rather than inwards), and had leaked a little fluid.
Truck still appeared to drive and perform fine. ESC, battery and all other components were cool to the touch.


My question is, as i can't replace it and i can't afford a replacement at the moment, is there any danger from running the truck? (provided there is no shorts anywhere ) or is the capacitor required for long term "safe" use?

[rushboy2004]

I wont risk it as you might get a voltage spike to the radio or servos.

 

I sure a forum member used to soldering work - they might be able to replace it for you

[Hardcore]

3 minutes ago, rushboy2004 said:

I wont risk it as you might get a voltage spike to the radio or servos.

 

I sure a forum member used to soldering work - they might be able to replace it for you

I'm pretty good at soldering myself, but it's within a sealed case and it's impossible to remove the failed capacitor without destroying the case and heatsink.

Am i right in thinking that the Capacitor prevents voltage spikes to the built in BEC?

[rushboy2004]

 

2 hours ago, Hardcore said:

Am i right in thinking that the Capacitor prevents voltage spikes to the built in BEC?

Depends on ESC but mostly likely. you could use a extra BEC to isolate the power.

They store some charge for when power is draw is required but when they have failed they wont hold power or correct power levels. If one has failed and it not holding the required power when you need it could damage something else. What ESC is it? if its bust what have you got to loss by having a go at fixing it?

 

hobbyking do some super cheap BEC.

£5

https://hobbyking.com/en_us/turnigy-5a-8-26v-sbec-for-lipo.html

£18 - I run these in a summit and its great.

https://hobbyking.com/en_us/rotorstar-super-mini-s-bec-6s-10a.html

 

 

[Hardcore]

The ESC is a Hobbywing 1080 crawler.
It's got a 3A built in switchable adjustable BEC so it's pretty good.

Not sure what the capacitor popped. It was a couple of seconds after an impact, so maybe something shorted?
ESC has and always runs cold. Never even gets warm when running a 17t motor on 3s and these days it runs a 35t on 3s
My battery should be good enough to stop voltage ripples i think so going to risk running it without the capacitor this weekend and see how i get on but will fit an external cap shortly

[Fly In My Soup]

On 2017-5-31 at 17:42, Hardcore said:

I've a Hobbywing ESC, with a built in capacitor.
I had a bad bump in my truck the other day and for one reason or another, after the bad bump, i heard a loud and short "hiss" like a tyre going down rapid.

On inspection, the capacitor on the ESC had swollen slightly at the top (bevelled outwards, rather than inwards), and had leaked a little fluid.
Truck still appeared to drive and perform fine. ESC, battery and all other components were cool to the touch.


My question is, as i can't replace it and i can't afford a replacement at the moment, is there any danger from running the truck? (provided there is no shorts anywhere ) or is the capacitor required for long term "safe" use?

 

Current peak blown your capacitor, you been jamming the throttle on whilst the RC was stuck/hung up on summat?? Only saying as you mentioned crawler

 

anyway hobbywing use cheap components, caps are made in china.

 

Either that or you ran over what the ESC could handle voltage wise, or reverse polarity.

 

You'll fry the rest of it if you run without a cap in place though.

 

When tengo used hobbwing esc's as a base they replaced all caps with Japanese ones for good reasons

Edited May 31, 2017 by Fly In My Soup

[locky]

There are capacitor boards that can be soldered for additional protection such as...http://www.ebay.co.uk/itm/Castle-Creations-CC-CapPack-Capacitor-Pack-011-0002-02-/131761305944?hash=item1ead95f958:g:-G4AAOSw0fhXiqoi or make your own.

[Hardcore]

1 hour ago, Fly In My Soup said:

 

Current peak blown your capacitor, you been jamming the throttle on whilst the RC was stuck/hung up on summat?? Only saying as you mentioned crawler

 

anyway hobbywing use cheap components, caps are made in china.

 

Either that or you ran over what the ESC could handle voltage wise, or reverse polarity.

 

You'll fry the rest of it if you run without a cap in place though.

 

When tengo used hobbwing esc's as a base they replaced all caps with Japanese ones for good reasons

 
It was a weird one. ESC is rated for 80A constant and 400A burst - Hobbywing 1080
Battery is rated for 150A constant (5000mah 30c)
14awg wires
Motor is a GoolRC 540, 35t and truck is heavy, but geared low.
Motor gets hot now and then when driving nuts, but ESC and battery never even get luke warm...

I was going down a hill, fairly flat at about 3/4 throttle and truck axle caught on a small hooked rock. Truck made an almighty bang (all metal SCX10) and motor almost stalled. It was less than a second before i let off. I walked over to unhook it and heart a type of pop then hissing like a small car tyre being burst. I thought it was the lipo, rushed over, disconnected then noticed a slight swell in the capacitor (though very small) and it had ejected some liquid.
ESC, battery and motor were all stone cold, so don't think it was current draw. Maybe a short from the bump? I've genuinely no idea tbh.
They're about £40 now and this is only 3 months old so be nice if it could still be used either without the cap (as i use low amp draw and good batteries) or worst case, external single cap.

 

[Fly In My Soup]

On 2017-6-1 at 00:04, Hardcore said:

and it had ejected some liquid.

 

That's just electrolyte, don't ingest it and you'll be fine 

 

On 2017-6-1 at 00:04, Hardcore said:

external single cap.

Couldn't advise on this never done it.

 

If you choose to replace the internal capacitors you should get the largest mf, as long as you can fit inside the case, just make sure you match the voltage up.

[Hardcore]

17 minutes ago, Fly In My Soup said:

 

That's just electrolyte, don't ingest it and you'll be fine 

 

Couldn't advise on this never done it.

 

If you choose to replace the internal capacitors you should get the largest mf, as long as you can fit inside the case, just make sure you match the voltage up.

The ESC design is a little strange.
The large capacitor is external, but the case design means it's virtually impossible to replace. To remove the case requires cutting it off and making it need to be sealed with shrink wrap

https://www.t2shop.de/HobbyWing-30112750-WP-1080-Brushed-Crawler-ESC-80A-incl-programming-card

I'm thinking of pulling off the popped cap and soldering this onto the battery leads instead

http://www.ebay.co.uk/itm/282480197115?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[locky]

Give it a go, let us know if successful.

[sunny]

That capacitor is 16v, are you using 2s or 3s?

[locky]

Caps need to be as close as possible to esc.

[Gaz!]

Where did you buy it from?

 

maybe ask for a warranty replacement?

 

both esc's (1080's) taken the nationals with no problems, taking spills and knocks and mud/water.

 

cheers. 

[Hardcore]

2 hours ago, sunny said:

That capacitor is 16v, are you using 2s or 3s?

 

Both. I run 2s sometimes, but 3s most of the time.
Standard capacitor was 16v also.
 

57 minutes ago, big gaz said:

Where did you buy it from?

 

maybe ask for a warranty replacement?

 

both esc's (1080's) taken the nationals with no problems, taking spills and knocks and mud/water.

 

cheers. 

I bought it from Hobbyking but not sure they'll honour the warranty as i've changed the battery connector side.
It's got about  3 months of use on it so far. It's taken a lot of bad crashes and submersions in it's time so it's strange it popped the cap the way it did.

[Isle of Wight Basher]

The damage could have been done before and it was just "it's time"

 

The 16V rating for the capacitor is the maximum voltage it can handle, it's good to allow roughly double the intended supply voltage, so it's spot on.

[Fly In My Soup]

+1 with i.o.w.b

 

After researching this morning, I can see that you can indeed over egg the voltage 

 

Some Japanese mod class drivers use banks of capacitors to adjust the ESC according to track etc etc.

 

As a basic rule , go for a higher voltage, higher mf/uf rating, and a higher ripple current rating ( if listed )

 

Apparently allows our esc to run cooler, smoother power cube etc

 

Also, on the issue of why it actually blew, I've read many times, that when a motor is suddenly stopped from a high speed run, the motor stalls, thus throwing out the timing on the ESC, which in turn causes electrolysis of the capacitors plates, which in turn creates gas thus expanding the capacitor until it pops, spewing it's electrolyte fluid 

Edited June 1, 2017 by Fly In My Soup

[Hardcore]

1 hour ago, Fly In My Soup said:

+1 with i.o.w.b

 

After researching this morning, I can see that you can indeed over egg the voltage 

 

Some Japanese mod class drivers use banks of capacitors to adjust the ESC according to track etc etc.

 

As a basic rule , go for a higher voltage, higher mf/uf rating, and a higher ripple current rating ( if listed )

 

Apparently allows our esc to run cooler, smoother power cube etc

 

Also, on the issue of why it actually blew, I've read many times, that when a motor is suddenly stopped from a high speed run, the motor stalls, thus throwing out the timing on the ESC, which in turn causes electrolysis of the capacitors plates, which in turn creates gas thus expanding the capacitor until it pops, spewing it's electrolyte fluid 

That makes sense and is probably what happened to mines. It would have went from about 70% rpm to about 5% and heavy load in a fraction of a second.

Going to see if i can remove this damaged cap with some pliers and hopefully there is enough bits poking out to solder a replacement in. If not then i'll need to solder the replacement cap on the ESC wires as close to the ESC as i can

[Fly In My Soup]

59 minutes ago, Hardcore said:

Going to see if i can remove this damaged cap with some pliers and hopefully there is enough bits poking out to solder a replacement in. If not then i'll need to solder the replacement cap on the ESC wires as close to the ESC as i can

 

Can't see anything wrong with those plans, who knows, with a better cap you may well turn an unfortunate event into a positive one, in regards to understanding your ESC and building one better than standard

[Hardcore]

So i discovered i am unable to return my 1080 for a warranty replacement for a couple of reasons, that are my own fault.

 

The warranty sticker is removed (i had it glued down originally an removed the sticker, for better bonding)
There is a few marks around the clips on the esc where the heatsink joins the body. This is when i had made a very gentle attempt to open it to try and get some de-case pictures.

 

Both my fault but obviously didn't contribute to the failure.

 

Since the capacitor popped and i ordered a replacement i figured that before soldering in the new one, the one old has to be removed to try and prevent further problems.

 

First attempt, to pull it out like a tooth.
Not possible to wiggle it side to side, due to how it sits in the ESC, so tried pulling it straight out and it fell apart easily, because it was already ruptured.
So with nothing to grab hold of and half a capacitor still on, it needed to be de-cased. Even with all the clips cut off from the case, the bonding from the conformal coating sticking the board to the case and heatsink etc, meant that it appears i have damaged the board in attempting to de=case it.

 

I'm not going to be put off as i think it was just purely bad luck so a replacement has been ordered and will stick my Hobbywing 1060 in with a Turnigy 5A BEC in the meantime.

[old and rusty]

had recently installed a steel spur gear/ slipper clutch on a Arrma granite 4x4.  it came stock with a 14 tooth  48 pitch pinion for the brushed motor.  (prior to this, it had been upgraded to a BL 3100kv motor, and a TSKY 120amp Hobbywing clone ESC and never had any problems) In the process of replacing the spur gear, one of the wires for the two caps was knocked off of the ESC and was soldered back on.  the spur gear replacement came with 3 pinions of 17, 19, and 21 teeth. Since they had come as a set, thought it would be best to use  one of those (the 17t).  After buttoning it all back up, and taking it for a test run it still accelerated, well and had decent top end, when suddenly (while still holding full throttle) it cut to about 1/4 speed, which it would do for approx. 20 seconds, then resume normal throttle. Forgot to mention he's running a  6 cell NiMH 3800 battery (if that makes any difference).  My question is does it sound  like  i've  just overgeared it, or  that I  could have problems with the capacitors? Will put the 14t back in to see if it helps, but if it's the caps, don't want to make things worse by running it. Any input would be greatly appreciated...thanks (sorry about the wordiness of the question0

[Tug]

Nimh is probably your problem. 

[old and rusty]

Update on the granite 4x4...upon pulling the gearbox back out found a small pebble behind one end of the assembly throwing out of alignment slightly, didn't think it was enough to cause binding in the drive train, but after going back to the 14t, and putting it back in the truck noticed that it did seem to turn a bit easier....that wasn't the problem. Still had the slowing down, then speeding up. When checking the motor temp. it was only slightly more than luke warm to the touch, and capacitors not warm at all (is that normal?) It's been suggested by some that the problem is the cheap TSKY ESC, and that you get what you pay for.

[old and rusty]

...and appreciate the input Tug, I'll try popping in one my lipo's and see if it helps