Why ESCs Fail....

[Fluid]

I thought it might be a good idea to revisit one major reason for ESC failure, and why some boaters seem to want twelve caps on their ESC. With the talk about poor LiPos recently this quote from a Castle tech on another site seems appropriate.


One of the most common causes of catastrophic failures in ESCS is using inadequate batteries or inappropriate plugs (too high resistance) between the battery and the ESC. Sizing batteries based on battery company’s claims of continuous current output is risky at best. It is always better to have at least 25% more capacity than you think you will need for a specific application. Inadequate or stressed batteries create excessive ripple current. The capacitors on the end of the ESC are there to handle ripple current. If there is too much ripple the capacitors become drained then overheat and either burn their leads, melt themselves off the board or explode. Once this occurs the ripple current cascades through the power boards burning the FETS.


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[fatboyelectric]

Great point indeed, maybe the single most overlooked factor in alot of boaters minds. Quality cells are of great importance. Opting for those cheap cells may cost you more than you think in the long run. Fluid I agree alot of folks have gotten cap happy. No doubt that Castle has seen alot of carnage from this, but in at least two dozen different units that I know of the #1 cause of failure of Castle controllers was trying to use them. lol

[Diesel6401]

I get it and it makes a lot of sense, but when after reading so many horror stories with the Hydra esc's there has to be something related to design flaw don't you think? I mean some of this issues are from really experienced boaters with lots of respect. Here's the latest:

I will be contacting Castle to when I have time to let them know its time for the Hydra HV series to be discontinued. While attempting to make the final connection with a one day old Hydra 180HV on 10s, the terminals arc welded in my hands, burning the skin and finger nails on my finger and thumb of my left hand, leaving them in a black carbon dust. Most everyone at the SAW event heard the bang it made, and came over. I thought I was done for at first. Checked myself over, and immediately checked to see what had happened. Postive wire to positive, negative to negative, jumper between the two packs to make a series setup, all the connector was gone into fire and dust. Quickly pulled the packs out for fear of meltdown. Doug Smock and Chris Harris come running over, we start looking over things. No popped caps-check, No reverse polarity-check, batterys voltage all checks out correct, and then Doug checked the setup using another technique on 2s to see if the controller was the issue. Sure enough, the 2s pack and controller made another welding scene on a smaller scale and in a more contolled way. We pulled the controller, and there it was, a hot spot on the control board. We confirmed this was a controller issue that created a dead loop inside itself.

I am very lucky, and honestly, Castle should feel lucky too that nothing worse happened. I hate to say it, but the HV hydra line as a joke, it has been, and apparently always will be. They have replaced it with the HV Ice series, so its time for these death traps to go. I am very disappointed and quite honestly contemplated walking away from FE yesterday because of this. After regaining my thoughts, talking to people like Doug Smock, we just decided we need to be safer. Fire retardant gloves and eye protection will need to be the norm from now one.

If this was a one time indecent, I would not point fingers, but I think Castle knows these are not good designs, and until yesterday I figured hey, if you get a bad one, they just go bad upon plug in, never in a million years would I guess a controller could dead short creating a very dangerous condition for the user.

Guys be careful out there, no matter what the brand. Never did I think a controller even had the ability to create a dead loop. Well, they do, so please take caution.

Mike

[fatboyelectric]

You got it, design flaws without a doubt. I was burnt just like Mike reports, had another go off in my p mono seconds after launch and that one cost me my batts as well, and yet another controller I was about to install when I discovered solder connecting all three motor leads at the board. I even had a reputable member of castles staff (wont mention the name at this time) tell me to run this controller and send it in after it fails! Clearly they dont consider liability in many cases.

[Diesel6401]

You got it, design flaws without a doubt. I was burnt just like Mike reports, had another go off in my p mono seconds after launch and that one cost me my batts as well, and yet another controller I was about to install when I discovered solder connecting all three motor leads at the board. I even had a reputable member of castles staff (wont mention the name at this time) tell me to run this controller and send it in after it fails! Clearly they dont consider liability in many cases.

With all the horror I heard of the hydras I chose to stay away from them and ran Seaking esc's over the CC which I must am very big fan of the seaking escs. I did pick up a Hydra Ice 240 which I am a fan off.

[properchopper]

Very pertinent, thanks Mr. Turner.

One related bit of advice I can add that goes right along with this, based on personal experience, is to think twice when the urge hits to go up "just one more size" with the prop. I've gone over the edge doing that when overpropping stresses the batt's to the point where ripple current gets destructive.

I've done data recording experiments with el-cheapo batteries all the way up to premium batteries, and to sum up what I found : while all the batteries started off with basically the same off-the-charger voltage, once load is applied the lesser batteries caved in pretty fast and would be most likely be the ones to enter the destructive ripple current zone.

I also must admit that I was once quite familiar with ripple current and its effects, although I mostly preferred strawberry

[Steven Vaccaro]

Thanks for the info Jay! I would like to add that a believe another reason for failure I find is over volting motors. Many customers are trying to go faster by putting another 2 cells in the system. Jumping from 4s to 6s.

[davey]

Hey there....I have 8 4s turnigy 35c 5000mah...that run in my buggy and truggy....Ive never had a problem with them...maybe once...when they got shipped...one was puffy....after a good run with the buggy, they are fairly warm to touch and puffy....knowing that they are not the best battery ,,I never push them to hard in a race....Question is.....I want to run them in my boat...will they be ok ,,,if I don't push to hard...meaning...full out steady....I do not want to blow a 300.00 esc

[martin]

I know it dosnt answer your question but anything that applies to car,aircraft etc re what works well on given setups to totally out the window on boats. I simply cant imagine their getting any where near the probs re what happens when pushing the limit on boats as we all want to.

[dana]

you should be running your boat at full throttle as much as possible. anything less puts alot of stress on the esc. as far as your packs, its always a chance with cheapo batteries....

[dana]

[QUOTE=Fluid;310648]I thought it might be a good idea to revisit one major reason for ESC failure, and why some boaters seem to want twelve caps on their ESC. With the talk about poor LiPos recently this quote from a Castle tech on another site seems appropriate.


so...does running 12 caps help? lol but on a serious note, i wonder how the new aquacraft batteries are? i mean whats affordable thats quality for us guys that dont have 150 bux for 1 hyperion pack

[davey]

Its a chance I guess...Ive been in buggy races where theres been my buddy (laggylarry)...hes smoked atleast 4 monster mamba esc's....I'm talking 2 foot flames...the whole buggy , gone up in smoke..garbage !!,,yet I have never cooked 1..I know boats draw alot more out of the whole...my trick is ,,I guess...2 or 3 full out passes...then bring it in and check...don't run 3 or 4 more

[Fluid]

I have to wonder how many of the HV Hydras were run with low-end packs when they blew. With the high battery cost of 10S setups, I know many have gone the cheaper route with Chinese cells. When these cave under high load they are more likely to burn the ESC than quality packs. I've seen it happen.

OTOH Castle has had problems with their boat ESCs in the past. The initial 80 amp Barracudas had major design/build problems, and Castle didn't really begin to understand the true requirements of boats until just a couple years ago when they actually started testing in FE boats. They learned a lot, including the lesson of inadequate cells. It would not surprise me that there is a problem with the HV Hydras, although several club members have run the 180 HV models extensively without problems.

The only ESCs I've burned up were used in SAW applications. They either burned up in the SAW boat, or they did later in another boat. Doubtless they had been weakened in the SAW runs and just gave up later. Many boaters forget the time they over-amped the ESC running one of Tony's BIG props - then when the controller fails a month later they blame Castle......


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[keithbradley]

Good post Jay.
Something else I have noticed lately is the cap adding trend. Adding caps can help but I feel there are a few who don't really understand what they do.
A cap is not intended for a constant drain like a battery, its meant to smooth out tiny current spikes refered to as current ripple. (Exactly what Jay mentioned).
I have read other posts in which people are intending to lower the voltage drop that is experienced under load. Caps are not what you need if your voltage is dropping excessively. You need one of 3 things. 1) More mah 2) Better batteries 3) A setup that will draw less current.
If your voltage is dropping below whats acceptable to you, you need to change one or all of those things. Caps are not intended to be extra batteries.

[Brushless55]

Ripple current is one thing I've learned a few years back as I kept seeing ERevo esc's getting tosted because it seamed they were using packs with low C ratings..

one thing I've noticed to with better (higer C rating) packs is even lastnight I tried out my Turnigy 5000mah 40C hard packs in my ERevo and the system runs cooler with a bit more punch while bashing!