Kraton Problem regarding swollen lipo

[KevinP]

Hi, I'm Kevin! New to the forums, but having the Arrma for a year now.

So basically a month ago I had this lipo battery up for a rough run in my Kraton. I've been bashing my Kraton through water, dirt and all other naughty stuff without trouble before. But after this clean, simple but rough sand/dry dirt run I happen to find my lipo battery all swollen up and what not. It got me pretty questioned but after some research on the internet I found out that due to the bashing through water and whatnot, water would've possibly been the harm, corroding the connection points inside the lipo between each cell.

I took the safe way out and ordered a new, but exact same lipo battery as it's performance did quite well IMO. I decided not to run it through ANY water again as I discovered lipo's weren't really waterproof after all. (I know, such a noobish action, as I read on the internet before they could perfectly handle some water)

So today I took the Kraton for a run again, with a brand new and fully charged battery. It was a pretty hot day and conditions were quite dry. I had a great time but sudden issues began to appear again. In single a run the car would "restart" itself around 8-10 times and each time you could hear the same beeping sound as when you turn on the ESC. Whenever it drove, it did amazing and had full power.
I continued driving and after a normal amount of time, the car went into lipo-cutoff ofcourse. When I took the body off I could see the blue light on the ESC blinking, which is ofcourse normal. But this time, again, I noticed my battery being swollen up even more. This got me questioned as to why this had happened again. And I'd be happy to find the answer here.
I'll list what I have changed about the car underneath.

-I've upgraded the pinion gear to a larger one, the one that's supplied with the kit. (Think it was 14T)
-I've thickened the diffs oil by putting new oil in them.
-I've upgraded the servo to a Savox SW1210SG. (http://www.savoxusa.com/Savox_SW1210SG_Waterproof_Digital_Servo_p/savsw1210sg.htm)
-I've upgraded to a new transmitter/receiver combo called the Spektrum DX4C together with SRS4210 receiver.
-The battery I'm using is a Team Corally Car Lipo 45c 22,2 volt 4500mah. (https://www.toprc.nl/team-corally-car-lipo-45c-6s-4500mah-met-dean-stekker.html)

I measured the swollen battery's voltage today half an hour (+-) after the run, and it was at 19,0v. I'm sure the charging is going fine and well aswell. I'm pretty much clueless, although my thoughts are going towards the Servo which is pulling too much from the battery I guess. I have to admit that I haven't ran the car a lot and rough like this ever since I installed the servo together with the new transmitter and receiver.(Minor trouble was the cause; loose pinionscrews, things like that etc..)

I think I have the V1 version of the Kraton, with exactly this ESC: http://www.arrma-rc.com/part/AR390120
And this motor: http://www.arrma-rc.com/part/AR390112


I'm already kind of planning to go towards the Hobbywing max8 combo, but I'd like your thoughts about this whole problem first though! I've tried to be as much as informative as I can.

Thanks in advance!


Greetings from Kevin.

 

[L3 RC]

I don't think it's an esc problem...

I think you are running the batteries down too far. If you're running a 6s single pack, your voltage shouldn't get below 19.2 at the absolute lowest. That's only 3.2v per cell. Ideally, your lipo cutoff should be 3.3 or even 3.4v per cell (19.8v)

If your car was shitting off, I am pretty sure that was your esc's lipo cutoff. Or, it was your battery failing. If it wasn't your lipo cutoff, that means you are running it in nimh mode and therefore don't have your low voltage cutoff enabled.

The biggest hint that supports this is that you are getting a half hour or more out of 4500mah. That's a lot of run time unless your taking it extremely easy.

Edit: just reread and you said you do have lipo cutoff mode enabled. If you do, then it's failing for some reason.

 

[KevinP]

I don't think it's an esc problem...

I think you are running the batteries down too far. If you're running a 6s single pack, your voltage shouldn't get below 19.2 at the absolute lowest. That's only 3.2v per cell. Ideally, your lipo cutoff should be 3.3 or even 3.4v per cell (19.8v)

If your car was shitting off, I am pretty sure that was your esc's lipo cutoff. Or, it was your battery failing. If it wasn't your lipo cutoff, that means you are running it in nimh mode and therefore don't have your low voltage cutoff enabled.

The biggest hint that supports this is that you are getting a half hour or more out of 4500mah. That's a lot of run time unless your taking it extremely easy.

Edit: just reread and you said you do have lipo cutoff mode enabled. If you do, then it's failing for some reason.

Thanks for your reply.

I have never touched the ESC it's settings before. It's still at factory setup as far as I know.

I've seen and read that the first version of the kraton's ESC wasn't that great and lots of people had issues with it.

However, I've ordered myself a max8 combo. So I guess I should be alright from now on lol

 

[Mikuri]

The first version of the ESC was prone to overheat and ultimately catch fire.
But I guess we'll find out if it was indeed your ESC. Or maybe the Lipo, who knows, maybe you were unlucky.

 

[dpricenator]

I use the Savox 1210SG servo and the Stock Kraton V2 Electronics. Never had an issue with a battery heating up or puffing under use or after a heavy bash.

 

[Crash]

"I happen to find my lipo battery all swollen up"

If it doesn't go away after four hours you should see a doctor!

 

[Dustin Mustangs]

As already mentioned above, you are over discharging your lipo and damaging it. The puffing is a sign of the damage. 19v is under 3.2v per cell which is waaay too low. I personally try not to go below 3.7v per cell resting voltage which is in accordance with the 80% rule. Google that if you are not familiar. There is also a lipo basics thread around here that would be worth looking over.

 

[KevinP]

As I said, I never touched the ESC's settings. The battery itself has a statement on it: "Do not discharge below 3.0v per cell.", so you'd say it shouldn't even swell up as I measured it at 19v. Which is ofcourse a wrong saying seeing as my ESC is already discharging it too much and in maybe the wrong way as well (Cell 1 could be 2V, Cell 2 could be 4V, etc..).
I know the cut-off should be around 3.4v per cell. But I just wanted to be sure by asking it here and give as much information as I could.

Anyway, I've called the hobbyshop I originally bought it from and they advised me to send it to them for a warranty replacement. They also mentioned it was a known problem with the V1 version of the ESC.

I've already got the max8 combo installed though. Haven't got the chance to try it out yet but I'll be sure to check every setting with the program card beforehand. Second question, should I set the BEC on the max8 ESC at 6.0v or 7,4v for the 1210SG servo?
Will a run last shorter if on 7,4? Do I have to change anything else before setting it at 7,4?

Thanks alot for your time and answers!

 

[Mikuri]

I don't understand why so many people go for the Savox 1210 while the 1270 is about same price but way stronger and a bit faster. The waterproof is a bit too much when you know that the 1270 is splashproof already and you don't play with a submarine anyway. And the 1210 is actually taller than stock servo so you might need to adjust things a little while the 1270 is "bolt'n'run".

Anyway, run it at 7,4, that's what I wish the stock ESC would do.