Traxxas 3300 3s

[sixhundred71]

I just bought this battery and every time I charge it the MAH only fills up between 100 and 500 MAH with each cell at around 7.4 volts. Do I have to keep cycling trough it to get to the batteries full potential? Or am I doing something wrong?

[Charlie-III]

The battery arrived with some charge in it, you are just topping it off. Go run it, then charge and see the mah put back in.

[fred0000]

aslso each cell should never exceed 4.2v I sure hope your not at 7.4v per cell you would be at 22.2v overall on your lipo.

[sixhundred71]

Sorry, each cell is at 4.25v. On my fifth charge the cells are at 4.25 with 392 MAH. The battery doesent seem to get warm when charging or running it either. And it usually runs for about 10 mins before going into low voltage on the VXL 3s. Any advice?

[Charlie-III]

Originally Posted by sixhundred71

Sorry, each cell is at 4.25v. On my fifth charge the cells are at 4.25 with 392 MAH. The battery doesent seem to get warm when charging or running it either. And it usually runs for about 10 mins before going into low voltage on the VXL 3s. Any advice?

What is the LVC set to on your ESC?
What rig?
What & how many motors?
I will assume your pack has Traxxis high amp connectors?
Does the ESC or motor/motors get warm near the end of the run?

NiCD's used to need a few cycles to get good, LiPO is pretty much good from new.

[fred0000]

if it's in a "go fast" RC 10 min sounds pretty good for 3300mah.

[sixhundred71]

Originally Posted by Charlie-III

What is the LVC set to on your ESC?
What rig?
What & how many motors?
I will assume your pack has Traxxis high amp connectors?
Does the ESC or motor/motors get warm near the end of the run?

NiCD's used to need a few cycles to get good, LiPO is pretty much good from new.

It's a wraith with a VXL 3s. Using deans plug. I didn't know that you could change the LVC on this setup. And the esc and motor is pretty warm after 10 mins of use. Isn't this battery supposed to last longer? I have a 3300 nimh and it lasts way longer than this.

[Charlie-III]

I'm assuming this is your ESC??.... Traxxas - VXL-3s ESC (#3355X) - Overview | traxxas.com
The LVC may not be adjustable, are you going into thermal overload???

Next time, let it sit for 5+ minutes, then run again and see what happens. You may be a bit overgeared and the ESC is overheating.

[sixhundred71]

Originally Posted by Charlie-III

I'm assuming this is your ESC??.... Traxxas - VXL-3s ESC (#3355X) - Overview | traxxas.com
The LVC may not be adjustable, are you going into thermal overload???

Next time, let it sit for 5+ minutes, then run again and see what happens. You may be a bit overgeared and the ESC is overheating.

yup, that's what im running. And I think its going into LVC mode because the red light is blinking slowly. When overheated the light will blink rapidly.
And my battery is also saying full charge when the mah is around 390. is this right?

[Charlie-III]

Originally Posted by sixhundred71

yup, that's what im running. And I think its going into LVC mode because the red light is blinking slowly. When overheated the light will blink rapidly.
And my battery is also saying full charge when the mah is around 390. is this right?

What charger & how is it set up?

The charger will show the mah put back in, so I would guess:

1-The ESC is shutting down early due to low voltage (not likely)
2-The ESC is shutting down due to heat (not likely)
3-The motor is overgeared
4-There is binding in the drivetrain (includes pinion/spur mesh too tight)
5-Charger is not set-up correctly, thus not getting a full charge in
6-Bad cell in pack/bad pack

[sixhundred71]

Originally Posted by Charlie-III

What charger & how is it set up?

The charger will show the mah put back in, so I would guess:

1-The ESC is shutting down early due to low voltage (not likely)
2-The ESC is shutting down due to heat (not likely)
3-The motor is overgeared
4-There is binding in the drivetrain (includes pinion/spur mesh too tight)
5-Charger is not set-up correctly, thus not getting a full charge in
6-Bad cell in pack/bad pack

Thanks for your help. Its an onyx 235 set to 3 cells,3300 mah and 3.3 amps.the drivetrain seems pretty smooth and the gearing is all stock wraith gearings. And how can I tell if I have a bad cell? The charger shows cell 1 @ 4.25
cell 2 @ 4.25
cell 3 @ 4.28
with 12 .79vp (dont know what this means)
@ 391 mah and the battery still didnt last long

Also when LVC kicks in I unplug the battery then plug it back in and it'll run for about anther 5 mins and I could do that 2 or 3 times.

[Charlie-III]

I will assume you balance charge?
-Look at each cell voltage when done charging
-Run the rig, check each cell voltage again to see if one is lower than the others

A difference of a couple hundreths is OK, 0.2+volts difference is getting to be a lot, 0.5+volts is likely too much.

As to unplugging and then replugging & it works, it's the cell voltage rebounding with no load on it. Pretty typical in any battery.

[sixhundred71]

K, I think my low voltage is going on too early. I usually stop running it and charge it, the volts per cell are around 4-4.25. And today I kept running even after the LVC went on by unplugging the batt and plugging it back in and it lasted pretty long. After doing that a few times I put the batt on the charger and the cells read 3.5 and it charged 1400 MAH and I've never seen it charge that much.
Also isn't there a safety system in the vxl 3s that stops the motor from running after the LVC kicks in?
And what is the lowest volts per cell that I can run my batt without damaging it as today the Volts read 3.5 per cell and it charged longer than any other time I charged it.
Oh, and when I'm binded up on something the LVC kicks in and after unplugging the batt and plugging it back in the batt will still last pretty long.
Hope this is enough info for somebody to troubleshoot. Thanks

[Erin]

3volts per cell is the lowest you want to hit.

[Goatsniper]

I have the vxl set-up in my wraith. its geared 60/10 and my rig also cuts off
like that in a bind. the other day i was using a friends 5000mah 25c 3s and it cut off when it got bound up. I unplugged the battery and waited a couple of minutes and plugged it back up. i ran that pack for at least an hour after that i just tried not to bind it up. i think i need to buy some better batteries with at least a 50c rating. i believe the motor and esc are trying to pull more power than the batteries can provide when it gets in a bind and its causing the lvc to kick in.

[JesterSpec]

That esc shuts down really early. I have it in my bandit.

If out of the gate I punch, the LVC will shutdown because of the immediate draw takes the volts down so far. I've never liked the VXL LVC for that reason.

If you turn off the esc, and turn it right back on, that will reset the lvc, and you'll get more run time if you don't full throttle it right away.

[Charlie-III]

For you guys with a 2000mah+ pack, a lower "C" rating is OK since the mah helps.
It's when you run ~1000mah and smaller packs that "C" becomes really important.

-Make sure you have decent pack connectors (NO Tamiya, Traxxas is OK, Deans or Sermos are better).

-Make sure you're not overgeared (the motor & ESC will get hot if you are), this puts a huge load on the ESC/battery when loaded up (hard acceleration or a bind).

I have no advice for the LVC in your ESC.

[wantAsummit]

I've seen this happen plenty of times with a VXL. You need a pack that will resist voltage drops under surge conditions. This is a combination of mah and c ratings (bigger for both is better). One work around would be to put it the VXL in nimh mode which will disable the LVC. Then you could just add a standard LVC alarm.

[sixhundred71]

My C rating is 25, so do you think I need a higher one ?

[wantAsummit]

Originally Posted by sixhundred71

My C rating is 25, so do you think I need a higher one ?

A 3300mah battery at a C of 25 can source 82.5 amps. I just looked up the specs on the Velineon motor: 65A constant, 100A peak/burst. You are probably just on the edge and that is why you are able to at least get some run time before the LVC trips due to a surge. It also depends on the age/quality of the battery.