Kraton ESC Help!!!!

[James899]

I'm having some issues with my ESC at the moment.
It's a BLX185, I run a twin 2s pack, twin 3s pack and a single 6s pack in it, all the batteries are fine, balance well etc etc
I have no issues on 50 or 75% power, runs great but regardless of which pack it is when I turn it to 100% after about 1 minute goes straight into LVC, on 6s it dies completely.
I've cleaned ESC fan out, so it's not an overheat issue and the fans fine aswell.
I've turned the car off and reset the end points to try and make it a fair test through every different combination of battery pack and power settings, but even from stone cold regardless of pack it just does.

Do you think the ESC has scrapped itself? I'm currently in the middle of an argument with my local hobby shop to replace under warranty!

Any help/info/advice would be appreciated!

 

[Ari33]

If you have a multimeter handy, check what voltage your Lipos are at when you hit this alleged LVC..

What Lipos and C rating are you using?

Are your bearings all good, no seized ones?

 

[James899]

It runs for 15 minutes or so on 75% on 6s, runs brilliant, pack after pack, but just does not like 100% power switch on the transmitter. Even with a freshly charged and perfectly balanced pack, it'll cut off within a minute
Just rebuilt it, with new bearings and diffs all round. It's not a mechanical issue.
The battery voltages are all fine

 

[Ari33]

What Lipos and C rating are they?

I've heard of similar symptoms on low C lipos. Just trying to eliminate these.
Has this suddenly hapoened after the rebuild?
Have you double checked your escs LVC setting?

Could you have something binding in the drivetrain and so its drawing excess amperage on 100% throttle... and that your lipos cant cope with the demand so you get major voltage droop and hit LVC.... or maybe your Lipos just cant cope period?

 

[nino]

What's your punch setting? Speed pinion? Really sounds like it cuts off because of V sag.

 

[James899]

What Lipos and C rating are they?

I've heard of similar symptoms on low C lipos. Just trying to eliminate these.
Has this suddenly hapoened after the rebuild?
Have you double checked your escs LVC setting?

Could you have something binding in the drivetrain and so its drawing excess amperage on 100% throttle... and that your lipos cant cope with the demand so you get major voltage droop and hit LVC.... or maybe your Lipos just cant cope period?

Graphene 6s 5000 45c
Overlander 3s x2 5000 60c
Peak Racing 2s x2 5000 45c

No it was doing it before the rebuild, I was actually testing it when the rear diff gear stripped and the only reason I rebuilt it was because I was bore this week and had a load of upgrades to put on.
As I say it runs fantastic, perfectly infact on 75% and gets really good run time, but just does not like 100%
These are the batteries I have always ran in it, that's why I think it's strange. I've done every conceivable test I can think of hit/cold/ different power settings, single 6s followed by twin 2s etc etc and it only every cuts on 100% regardless of temperature or battery pack.
It's never ever done it before that's why I think it's the ESC

What's your punch setting? Speed pinion? Really sounds like it cuts off because of V sag.

Standard, factory settings, I even checked this on the bleep settings

 

[Ari33]

If the Lipos are in good condition, fairly new, are showing reasonable IR and you are 100% sure about that.
I'd maybe try inspecting and opening up your lipo connector bullet ends by 1mm or so just to rule out a loose connection. With a loose connection arcing can occur within the connector bullet and resistance builds up as it heats up and amperage increases.
Not saying it definately is that but its worth checking before you start swapping out stuff.

Do you have a temp gun to read the motor and esc temps? Well worth investing in for situations like this..

 

[James899]

Just found the same fault in another thread, couple of people have had this issue and the BLX185 has been replaced and cured the issue.
The warranty in the UK is dog crap compared to you guys in the US. Horizon have your back over there, here we have to fight for stuff to be replaced. Well only 20months left on the warranty for more arguments ?

 

[Ari33]

If its not down to the motor, a new ESC will likely solve it but its defo worth checking for bad solder connections going into the plugs and for arcing with the bullets as they do work loose over time.. its not unheard off..
I had connection issues that were heat build up related once... turned out to be a bullet conector arcing in one of my plug convertors.

You aren't using additional connectors such as ic5/ec5 to xt90 convertors are you?

 

[James899]

If its not down to the motor, a new ESC will likely solve it but its defo worth checking for bad solder connections going into the plugs and for arcing with the bullets as they do work loose over time.. its not unheard off..
I had connection issues that were heat build up related once... turned out to be a bullet conector arcing in one of my plug convertors.

You aren't using additional connectors such as ic5/ec5 to xt90 convertors are you?

Thanks for the info mate, no, no adaptors, they're all ec5 soldered connectors! I'll check them to see how they look, you think if they're not perfect, just change them anyway?

 

[Ari33]

I think you should be able to tell with a bit of testing..
After a run where it has hit your LVC are any of the connectors/wires particularly hot? One of my connectors was noticeably hotter than the others and sure enough I found evidence of arcing.. although please note that a dry solder joint coild have caused similar symptoms.
Inside the positive female bullets or on the ends of the males you might see some arcing if they have worked loose over time.

To check the connectors solder joints you will need a multimeter.

If your multimeter isnt auto ranging.. Set you meter to Ohm x1K (1000)

Touch your negitive and postive meter terminals together, you should get a reading of zero. If you don't get zero you need to zero out your meter if it is analog (with a needle). Digitals most always zero them selves out. Zero shows there is no resistantance to the small amount of current running through the terminals.

Touch the positive lead to some part of the wire before the solder joint. I usually push the sharp end through the insulation to the wire to make contact.

Then touch the negitive terminal to the end of the post of the connector on the other side of the solder joint. If there is no resistance your meter should read zero. If it says anything other than zero (i.e. 1, 2,3,etc... or it is higher by that magnitude than your attempted zero) you have resistance and it is indicative of a bad joint. You will need to resolder this joint to assure good current flow.

High resistance in an electrical circuit will hinder the current from flowing at its full potential and show similar effects on the esc to running a lipo with a low C rating.

 

[Ari33]

If that all shows clear and you have a cordless drill handy you can also check your motor windings using this method..

If the motor shows up clear then you should go ahead with the ESC warranty claim

 

[jondilly1974]

There’s something wrong with the recent BLX ESCs. Even @Lovestricken had issues with his new Infraction ESC. All the BLX100s seem to hit LVC early too. I don’t know that I would trust buying one today.

 

[3d-rc.myshopify.com]

Yeah I had issues with my infraction fresh out of the box. I wouldn't recommend one unless you are using a blx 185 for like a granite. Even then I have amp issues trying to even climb a hill at times.
It's not so much an lvc issues as an amp limiting issue. It gets what I call a warble sound off the line. Like someone has added traction control to it lol