We were setting up our cars when all of a sudden one of the capacitors blew its top open, and the second one puffed up on us. Everything including the ESC and wires were hot.

I checked all the connections and nothing is reversed. Also, with the heat shrink and solid connections we made it's impossible that something like motor wires or battery wires shorted out.

What could have caused this?

We've never made any runs on the cars, they're brand new. We were setting up the steering and gear lash, that's it.

This morning I tried to plug it back in, and nothing heats up. The ESC also still works. Steering and throttle controls both seem fine, however the caps are blown!

The wire to the cap was reversed. The red semi-circle side goes to the negative battery post. Don't race it without at least one 330uf or higher cap. it keeps the esc cool by filtering RF noise.

Is the wire to the cap you speak of internal?

I had a similiar thing happen a couple race days ago, the one way diode on the cap board let the smoke out for no reason. I replaced it with another single cap and it seem okay now.
Ive had nothing but problems with the Hobbywing ESC's

Great! They came highly recommended so hearing you've had nothing but problems is kind of ..... not what I wanted to hear!

I talked to HW tech support this morning, and they tried everything to blame it on my setup. But I'm not new to wires, wiring things up, soldering, etc... There is no way in hell I can see that we could have shorted these out.

When pressed the HW tech kept going in circles. I mean, heck.... we never ran the cars so that takes out a lot of variables. Pretty much leaves leaves connections or shorts, which I can't find any.

Electrolytic power caps act as a battery on DC, Filter with AC. They explode in over charging, and or shorted out internally. Phenomenon as they say in electronics.

In all reality that's pretty much all I could come up with is an internal short somewhere. HW was hearing nothing of it. It had to be my configuration they said.

Like I told them... I could really care less about having to have it repaired or whatever. My thing is I don't want it to happen again because of something I missed or, am missing.

Yes, this is how they operate. I got sick of the run around from them after two 3.1 1s ESC's failed for no reason (DC BOOSTER failed, the other will not go into calbration mode). Finally just decided to buy another brand of ESC

it should connect to the side of the esc. look at the top flat part of the capacitor and there is a red half circle. The rigid wire under that goes to the battery --.

Tekin is the same, but your battery wires are between the motor wires so read carefully.

https://www.youtube.com/watch?v=fLOfyfWfqvc

13min in

Thanks, but the caps are totally encased in the ESC body. I guess what I was asking was is this a factory mistake that you are referring to?

By the marking on the caps exterior I can see they are the exact same on the other ESC of the same kind that we have.

On the Juststock xr10 the cap is on an extension wire.

Just buy a new cap at radio shack and tap into the battery wires.

While I certainly appreciate the advice, these are brand new ESCs. I'm not really looking to repair them myself no matter how easy it may be.

At this point I think I know this was a defect within the product and nothing wrong with our configuration. I'll go from here with HW.... who better step up to the plate. I don't take BS from companies lightly, and most regret having played the games with me.

I found this interesting and thought some might read this and appreciate the heads up. I certainly would not have bought Hobbywing products had I known this was there MO.

Let me tell you without any doubt what -so- ever .... the battery and all other connections are hooked up just fine. The cars had never been run, we were setting them for the first time.

__________________________________________response from Hobbywing tech support_____________

Hello, I am Jim from Tech Department. I am sorry to hear about the damage and we are glad that your daughter was safe.

The only reason why capacitor pops is when a battery is connected backwards. We also strongly recommend you to keep away from children when you work on a R/C hobby project, it is not a toy. Please pay extra attention when you install devices.
According to the manufacturer warranty terms and conditions, this case will be handled 'misuse' that there is a repair fee.

That said since you are a valued customer, we are more than happy to issue a free replacement ESC for you (one time only): however, please cover the shipping fee. Please send the unit to the following address.