Cheap Chinese ESC

[Peter Brown 15Participant @peterbrown15]

A burning issue.

[Peter Brown 15Participant @peterbrown15]

I connected my battery, 7.2v 3500 Tornado to a cheap esc. I had previously used the esc in my small tug boat and it behaved ok running a 380 motor. The esc got very hot within seconds and started to smoke and i removed it instantly. I then replaced it with another exactly the same esc and the same thing happened. I've now gone for a waterproof mtroniks 15amp to run my 380 motor. I also had a problem with my overlander nx-20 charger 2amp output with the same batteries above. The battery was fine but the charger got to the point where it was extremely hot and I believe would have gone up in smoke. I wondered if it was my cheap esc or the battery or both that is causing the problems.

 

 

 

 

 

Edited By Peter Brown 15 on 30/04/2018 08:06:49

[Malcolm FraryParticipant @malcolmfrary95515]

The specifications on Chinese ESCs tend to be ………..optimistic. I have used them without problems on small, lightly loaded motors without much in the way of problems. I very much doubt that the makers bothered to actually test their design under "real" conditions, just looking at specifications of their components and picking numbers off motor data sheets and trusting that, since the design seemed to work with one setup, it would be OK with anything that the words on the paper said was within limits. Sort of "It works OK with motor A that wants 2 amps, the chip specs say that it can handle the current that motor B wants, so it will be OK".

The problems I have had that resulted in the magic smoke getting out were entirely my fault, (supplying power to what should have been the 5v output, for instance) but I have never been able to bring myself to trust the more improbable claims for such tiny components (and thin wires) being able to handle the loads claimed.

The other problem did not involve destruction – it was related to non-recovery from a brown-out condition, where the boat had to drift in and be switched off and on again to get control back.

[ashley needhamParticipant @ashleyneedham69188]

Peter. The reliability of cheap Chinese ESC`s are always in doubt, but to have two go at once may be considered to be odd.

​I would carry out some testing at this point, and the use of a simple plug-in wattmeter would be very useful here> for instance>> https://www.componentshop.co.uk/battery-testers.html

​But available elsewhere. put one male and one female connector of your choice on the leads and plug between battery and esc/motor/woteva (if it does not come with plugs as sold).

Your overlander charger should be ok, a well known brand, and it is a bit subjective but chargers do get warm or even very warm to the touch. My electric bike battery charger (unvented) get very warm indeed, and my Nimh Batt chargers also get quite warm when charging for an extended period.

​I would connect the battery to the motor via a watt meter and see what the current draw is (in the water) to see if the motor is shorting out or something, and try that battery charger with the wattmeter on the battery to see if the maximum current is not being exceeded. Personally I like to charge batteries at a lesser rate, and use the 300mA setting on all my batteries. Do you have another battery?

​A lot of people like to use car ESC`s and there are well known brands out there at very reasonable prices if you want to stay in budget.

Ashley

[Empire ParkstoneParticipant @empireparkstone]

I can't say I have found his replacement esc brand all that reliable also the OP says extremely hot not just very warm it would be of use if we knew which esc he had the problem with.

[Charles OatesParticipant @charlesoates31738]

If it helps, I tested a Chinese ESC with an ammeter not long ago. It was a type often seen on auction sites and claimed 320 amps. I first used a 6 volt battery connected to an old 540 motor and made a simple brake to put a load on the shaft, some mates were considering the ESC s for springers. I got up to 10 amps, without a burnout, but the unit became unreliable, cutting out and needing to be switched off to re set. I then used a 7.2 volt NiMH battery when I got to 12 to 13 amps it started smoking. That's around 90 watts.

I'm certain these things have a wide spread of tolerances, and you need luck to get a good one. My models take a long time to make, and I'm bxxxd if I'm going to save a few quid and risk loss, fire, and misery.

Incidentally, I have 3 vipers, the oldest is about 12 years old and never had a problem. Others will have their own favourites.

Chas.

[Dave MilbournParticipant @davemilbourn48782]

Continually charging a NiMH pack at a high rate like 2A is never a good idea unless you regularly give it a couple of slow discharge-recharge cycles. By "slow" I mean with a current of around C/10 – in this case 350mA. Like Ashley I never charge at more than C/10. The web page for the charger you have doesn't mention it having automatic cut-off [often termed "Delta Peak"]. Does it actually turn off without your pressing the On/Off button?
You don't say whether the MTroniks 15 is running OK from that same battery so we can't eliminate the battery pack as the problem, although IMHO those cheap Chinese ESCs are not worth the cost of the postage – which is usually FOC anyway.
As an aside, I once had a conversation with a customer who told me he bought his ESCs from China at £4 each in batches of 10. He went on to say that, of the ten, six just wouldn't work at all, two would work for a while and then stop working, one would work OK but occasionally just stop and start again and the last one would work fine for a season. When I asked him why he didn't just buy a decent British-made ESC with a full warranty and backup service he said "but mine are only £4 each". I'm still trying to work out the logic behind that – like Eccles' piece of paper for telling the time!

DM

Edited By Dave Milbourn on 30/04/2018 12:56:56

[Peter Brown 15Participant @peterbrown15]

Thanks for all your comments. In fact my new mtroniks ESC refuses to give me reverse so I’m ditching it. I’m also going for a 500ma Vapex charger instead of the 2amp I’m using at present.

[Empire ParkstoneParticipant @empireparkstone]

It's unlikely no reverse is the esc are you sure you followed the setup instructions correctly

[Dave MilbournParticipant @davemilbourn48782]

Peter

I think you have to set one of those up initially to give forward-and-reverse by playing with the throttle stick while watching some pretty lights. If you've already done that and it still won't play ball then contact MTroniks and they will probably replace it free of charge. They have a good reputation for that sort of thing. With the money you save you can buy a new battery pack from a reliable UK supplier e.g. Component Shop. That'll give you a totally fresh start.

Dave M

[Charles OatesParticipant @charlesoates31738]

The set up instructions are on their website, I agree that's the most likely problem.

[Mark Jarvis 2Participant @markjarvis2]

My initial though when i read the opening post was, that, the battery pack has a fault, possibly 1 cell has died, have you done a voltage check?? and a load check, like Dave Milbourn, hi charge rates will kill a battery very quickly. you dont mention charge times, how long before the charger got hot?

Mark

[Malcolm FraryParticipant @malcolmfrary95515]

A dud cell in a pack will upset a lot of things, but it is unlikely to cause an ESC to burn out. Among other things, they can cause "smart" chargers to become confused, because however smart they are, they can't spot a dud cell in a pack (apart from LiPo balace chargers).

My ESCs that have smoked have been because I did something silly, and I suspect that it was usually the BEC being abused by my mistake. It is quite possible to connect an item incorrectly, let the smoke out, fit a replacement making exactly the same mistake, and get the same result. Been there, got the T-shirt.

[Peter Brown 15Participant @peterbrown15]

Got to the bottom of my ESC blowing. I've got a sound module fitted and this was shorting out and frying my ESC's( Chinese & mtronix viper). I've now fitted a fuse between the battery and ESC and got rid of the faulty module. Also gone for a Vapex smart charger with is rated at 500ma and doesn't get hot. I've dipped my Chinese ESC's in plasticoat to waterproof them.

Edited By Peter Brown 15 on 06/05/2018 11:23:34

[Empire ParkstoneParticipant @empireparkstone]

A few apologies to cheap Chinese esc's perhaps

[Paul TParticipant @pault84577]

Re Chinese ESCs……remember the old adage of 'buy cheap buy twice' well it certainly applies in this case and is tremendously more expensive if your model bursts into flames in the middle of the lake.

Be warned because it will happen.

[Dave MilbournParticipant @davemilbourn48782]

I've dipped my Chinese ESC's in plasticoat to waterproof them.

You'd be better off coating them in chocolate and eating them, Peter. NEVER coat circuit boards with anything except proper professional conformal coating. Most ordinary clear varnishes are flammable, even when set, and they render a PCB completely unrepairable. Not that you're doing much harm that isn't already built into these things. Stick to MTroniks or maybe ACTion or Electronize. The poor reputation of cheap Chinese ESCs is well deserved, even if you know a bloke who's had the same one for ten years and it's never gone wrong. He's either a lucky man or he runs a very lightly-loaded motor.

Dave M

[Colin BishopModerator @colinbishop34627]

Not sure if he meant varnish or one of the spray coatings used to protect electronics.

Colin

[Peter Brown 15Participant @peterbrown15]

Colin, the plasticoat is like a rubber solution that you can dip stuff into as I've done with my esc or can be brushed on. Leave it for a few hours to set and you get a neat waterproof covering, see YouTube.

[Malcolm FraryParticipant @malcolmfrary95515]

The rubbery coating not only keeps water out, it will do a grand job of keeping heat in. This could change an ESC that is a bit near its limits into a very marginal one.

[Charles OatesParticipant @charlesoates31738]

Hi Malcolm and all, I've never heard of a manufacture using that to cover a circuit, I'm sure they would if it was a good idea. Even a tiny break in the stuff would let moisture in, and it would be trapped there doing its damage.

Is it ( in ) flammable when dry?, if it is, there could be a proper blaze when it goes wrong.

Chas

[Peter Brown 15Participant @peterbrown15]

Correction the stuff is called plasti dip
I haven’t had a problem so far. Look it up and see what you think. If my boat catches fire I will report back.

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