namewasdallas

So im having a major issue with my Losi Ten Scte, I got it setup for racing and im running a savox 1258 servo and a Rx8 Speed Control and Tekin Pro4 4600 motor. I haven't had a single issue with the truck untill now, Last night it puffed my Turnigy Nano Tech 65-130c, 2s Lipo which I've always ran in the truck with no problems. I have gone in on the rx8 and turned back the power and I think I lowered the timming a little bit to help keep the heat down. I've temped it many times and the motor and speed control ran at 140-150 and thats with a broken fan on my rx8 that doesnt even work.

Well last night I let my buddy drive the truck out in his front yard and he was doing fullspeed runs and jumping the driveway. We ran the battery basically dead I have the cut off set at like 3.80 for each cell or something like that. When I took the body off the truck to unplug the lipo the hardcase on it had poped open and the cells were all swollen popping out. The battery was super warm, Usally when I drive the truck the battery temps around 100 degrees. I forgot to mention I run Novak Copper wires that are a thicker gauge and all the wires are super short to help transfer electricity with less resistance and to cut down on heat. I use the castle plugs to push into the hardcase lipo.


Why all of sudden is the truck puffing my good lipo's? is it from him giving it to much throttle and the motor pulling to many watts? (Motor and ESC werent hotter then normal 140-150)


Lipo's are always charged on my Venom Pro Charger at 4.5 amps-5amps and always balanced charged to .01 from perfect

Foxy

My first concern is the cutoff you mention...3.8? That's very HIGH. If you mean 2.8, then that would be the cause of the puffing. Set it to 3.0 minimum, ideally, 3.2. Alternatively, the battery could have just reached the end of its useful life, or had a cell which was always destined to have a short life. How many cycles did you get out of it, any idea?

Other things to consider would be friction in the drivetrain or other moving parts, bad bearings causing high current draw? Could even be a fault with the ESC, its unlikely but it's possible. Certainly sounds like you aren't doing anything 'wrong'.

namewasdallas

Maybe its the LVC i always ran it higher then what most people do and I still would get lots of run time. I have cycled the battery over 100x ran it for almost 2 years now. I was looking at the battery today and I thought it would of just been 2 flat cells inside cause its a 7.4v but there was actually 3 flat cells all stacked together. Maybe Turnigy is selling the 2s 65-130c as 2s but there really 3s?

Foxy

Well a high cutoff certainly wouldn't be the problem, but that battery had a decent life, don't sweat it. If it puffs another battery, then perhaps look at other factors.

You need to check your settings though and verify the cutoff. 3.8 is unnecessarily high.

SyCo_VeNoM

impossible

and yea that battery did its time

jayjay283

So everytime you were done with the 2s 7.4v lipo, it was at 7.6 volts, then you charged it up again ? I would think you would hit the LVC when you accelerated after 5 minutes

SyCo_VeNoM

nah I have mine set to 7.4 volts and it takes 5000mah packs about 15-20 mins easy to hit them generally

jayjay283

I guess it depends on the esc. Some brands are more sensitive or those turnigy 65c really held their voltage under load till it just puffed to death

namewasdallas

I never had a issue with the turnigy batterys unless there to low a C rating like in my speed car, its a 2wd hpi E -Firestorm on a castle 3800 and MMP I got it geared and it will do 70 on 3s with a 25-30c and it puffs those lipo's every single time after a few full throttle runs. It did get one of my 50-100c 2s lipo's warm and puffy a tad the other day at the park when I was running it but the case I had already taken apart and taped back together. So something is deff wrong.

Could it possibly be a bad connector , I checked them out and they looked fine and fit tight and all my connections are solid.

I'm really thinking that having the truck wide open to much but to much strain on the lipo and couldnt handle the burst. Usally when I always ran it on my buddys track we never ran it wide open all the time because it wasnt large enough.

To someone that said they dont think the lipo's are 3s, I wouldnt think they are either and im not sure if they are. But I pulled it all out of the case and there was 3 indiviual cells. I would of thought a 2cell lipo would only be 2 single cells but this was 3. If I got time later I'll pull it apart and snap a pic.

Foxy

I think we're talking about separate cases. Your 2 year old turnigy died of natural causes, I'm sure of it, they don't last forever. You got a good life out of it too. Over 100 cycles over 2 years is good going for what you pay for the turnigys.

As for the firestorm, again I'm not surprised you're puffing 25-30C batteries doing full WOT runs with that motor, its a juicy beast. Finally, the 50Cs getting 'warm and puffy', is also normal and fine, as long as they don't get hot and fat. That 3800 can pull 100A easy on burst, more if you're geared for speed. What capacity are the batts we're talking about in the firestorm?

The 2S/3S thing is physically impossible, unless there is a 3rd cell in there that isn't connected, which would be weird indeed.

SyCo_VeNoM

sure the one "cell" isn't just a spacer so the battery dimensions don't change?

namewasdallas

Well the rx8-pro4 motor swelled up both my good Nano-tech lipo's. The one was so bad it broke the hard case wide open. I think it wasnt because the lipo was old it still ran like a brand new battery till the other day. And to have it happen to two batterys something has to be up.

My Firestorm is geared for speed runs I got a 31t pinion and 77Spur with a light weight slipper clutch setup and titanium shafts in the tranny form the Biltz Ese Pro.

I run the cheap turnigy 3200mah 25-30c soft 3s lipo's bought a bunch from this kid when I first got into it so I could run the truck. The 3800kv CC deff has alot of amp draw/watt draw under WOT and the MMP handles it fine the Lipo's just swell huge and get hot. I want to get some higher discharge 3s lipos.

my buddy has a 103mph rustler on 6s and with high C rating packs under WOT they never swell or get hot with the Mamba monster 2200kv setup.

I just think that the 2s Nano-Tech's cant take WOT with the Pro4 4600kv motor constantly. But sudden bursts like when I race on the track there's no issue, It all happened when he was running it WOT back and fourth across the yard jumping the driveway. I think my rx8 is set to 80% and like 10 timming. Whatever everyone else usally runs so it doesnt get hot and I got a 14t pinion on the Losi that the rx8 is in==</p>

Foxy

3200*25C=80A. The Castle 1410 will eat that battery for breakfast in only a few cycles. Your friends car doesn't even get warm because the load is being split across 6 cells and the motor is virtually unloaded (a rustler on a 1515?? lol, the motor probably doesn't even realise it has a car attached. ), so no real surprise.

You should not run timing at all on 4-pole motors. I'm not sure about the Pro4, but I assume its the same case as the Castle, and will actually run better on 0 timing.

For both cars, you need 200A nominal batteries if you want to be able to abuse them. Either 5000mAh@40C or 4000mAh@50C. If you are disappointed with the results from the nanotechs, consider getting the Gens Ace packs next time from hobbypartz. I've not tried them myself, but everyone says they are just as good as the nanotechs for about the same money. Maybe worth a try.

namewasdallas

Here's another thing I noticed when I first plug in the battery then turn on the transmitter and flip the switch on the rx8 it will only chime once and not twice. I'll get steering then I gotta play with the throttle and steering and it will chime again after a lil bit. I dont hit anything at first it's like it has a glitch.

Also when I first turn on the rx8 and it wont give me throttle the first 3 lights are lite up on it as well.

I noticed the other day driving it at my girls grandparents that when it got like a 100yards away it would glitch and I would lose all power for a lil bit then it would start back up again. I

I just ran it for 5min with my nano-tech 50-100c pack and it felt like that was getting warm as well so I stopped.



Onto my 2s 65-130c Nano-tech, I just took the lipo out of the hard case and there was 4 single cells all wired together stack one on top of another. I thought a 2 cell was just 2 single cells wired up with a spacer under it but that wasnt the case.. </p>

jayjay283

2s2p vs 2s1p

SyCo_VeNoM

sounds like you need to center your throttle trim, and calibrate the ESC.
and in between batteries you probably move your trim slightly
it chimes the 2nd time when its armed, and that is when the throttle is where you programmed it to.

namewasdallas

I do have my throttle trim set way back I noticed today I'll have to adjust it and see if it will chime twice. I'm going to try and charge that 65-130c nano-tech in my Lipo charging bag incase the thing catchs fire.

I thought 2s2p was only 2 cells parrael

SyCo_VeNoM

ahh missed where you said it was 4 cells
if it was 2 cells parallel it would be 3.7 volts only
that makes sense now what you were saying parallel batteries cell count is equal to the #S*#P like a 3S2p would have 6 cells inthe package, but wires to give the same voltage as 3S Its done to raise the total packs mAh capacity.

remember to recalibrate the ESC though

namewasdallas

so what does each cell equal to in volts?

I'm gonna go on my rx8 and and make sure I readjust everything. I'm pretty sure on the Pro 4 motors we run 10 timing on the hotwire setup

jayjay283

2s.... two cells in series doubling voltage 3.7v x 2

2p... two cells in parallel doubling capacity mah x 2

for a 2s2p, 7.4v 5000 mah you would need 4 3.7v 2500mah cells it could also be a 14.8v 4s 2500mah lipo

namewasdallas

makes sense now why there was 4 cells in the 5000mah 60-130c Nano-tech. I'm going to tape the battery case shut and try to charge it up again and run it in the truck and see what happens.

Foxy

You must like fire.

(to be honest, it's not likely to catch fire, but there is a risk). Don't mess with bad lipos, seriously, it's just not worth it, it's not like they are expensive.