Losi Baja Rey 1/10th 4WD RTR desert truck

[fyrstormer]

I wonder if there's a bad solder joint inside the ESC that's overheating and sending the whole thing into thermal shutdown.

My batteries are all 2S 5000mAh 35C.

[jreckner]

kind of what I was thinking. I'm surprised they recommend a 30c for this truck but im guessing its due to the huge motor drawing so much juice to quickly on a higher c rating?

[CM9000]

With bigger powerplants you want to use lower c ratings and maybe if you can turn down the start up amp draw. Some esc you can. Im running 7200mah rcking at 60c and ive got no issues. Higher mah helps too. The battery can take it.

[Rjohn929]

Why do you want lower c ratings?

[fyrstormer]

I think his idea is to decrease the amperage burden on the ESC by making the battery a chokepoint. Personally I'd rather run a beefier ESC instead, and run a battery that can keep up.

[Rjohn929]

That's how you puff and destroy batteries. Your battery needs to be able to support the draw from the motor/esc. Just because your battery is capable of producing 200amps doesn't mean it's going to. It only will provide the current the motor needs.

[Rjohn929]

It almost sounds like the batteries are not balanced or you have a bad cell that ls dropping voltage and causing a low voltage situation.

[DavidH]

Originally Posted by jreckner

just motor. seems like lipo cutoff at first then if I try to keep going it all cuts out for a second or two. What c rating batteries are you guys running?

I suggest buying a $10/20 LiPo battery checker so you can see the voltage by cell on the fly.

I bought one so that I can see in the field how much battery I have used, and for using my LiPo batteries with my non-Lipo-esc-equipped RC vehicles.

[jreckner]

Is it possible for a battery to balance out perfectly and still have a bad cell? It is a 7000 65c and balanced out almost perfectly.

[Rjohn929]

I think it is. Can you check resistance on each cell from the charger?

[jreckner]

no. just balance

[TTDRIVER13]

Originally Posted by jreckner

just motor. seems like lipo cutoff at first then if I try to keep going it all cuts out for a second or two. What c rating batteries are you guys running?

I was told by Losi anywhere from 30-50 when I first got mine. I have a 5600/35c and 6000/40c

[TTDRIVER13]

One thing led to another and here we are.....

[fyrstormer]

Even if you can't test internal resistance on each cell, you can balance-charge the battery and then run it until the vehicle won't move anymore, and check if the cells are still balanced at the end of the run.

[CM9000]

TT let me know how that thing runs in 2w. get a video too. I wanna see. really bad.


and btw, ive only had one battery puff in my times. and it was because it was a higher c rating and a burst rating of 180c and I was running a speedjems 5.5 mod in 4wbuggy. battery got hot, puffed, and went back to normal size the next day. lower c ratings help. it doesn't kill the battery. to quick of draw can kill it. the c rating just slows it down.

[Rjohn929]

That's not how batteries work.

[Rjohn929]

http://www.revolectrix.com/tech_data...y_C_Rating.htm

Because I don't feel like typing it out.

[Rjohn929]

Batteries can puff slightly while using them. It's normal. It depends on capacity and the size of the case. The battery DOES NOT dictate how many amps you use. The motor/esc does. If your battery can not support that it will cause permanent damage to the battery. You problem had nothing to do with the C rating.

[CM9000]

what im trying to say is that yes, the higher the c rating the faster it will drain. that was my point. and my experience.

[Rjohn929]

Only if it's required from your setup.