Arrma Kraton lvc issue ?? Maybe

[leyla1989]

hi all I run it for the first time yesterday for 6mins
On a 5000mha 14.8v 4s I then turned it on this morning for a little bash , after 2 passes it entered lvc , the esc flashing red . I turned off and turned on ok for one pass entered lvc and then same again turned off then entered lvc .
I just plugged into charger and states 3.86 3.84 3.87 3.84 and says output 15.46v ish

Why is the Kraton going into lvc as that is what user manual states for lvc red flashing light ?

Battery is new
Help ?? Cheers leyla

 

[DavidB1126]

Maybe esc or motor thermal detection? But if you did 2 passes or for 6 mins I don't see why the motor or esc would get hot already. Usually I see LVC set to anywhere to 3.0 to 3.6 volts per cell. 3.0 per cell is kinda risking the battery there. I wouldn't expect LVC to be set that high at 3.8 which is storage voltage.

 

[leyla1989]

Definitely lvc it says the led would be green for thermal protection

 

[nino]

Bad batteries? If they drop to LVC under load...

 

[WickedFog]

Ok, some potential red flags here.

First, did you unplug the batteries after the first run? Never leave a LiPo plugged into your ESC.

And second, just because your batteries are at 3.8v at rest doesn't mean they aren't dipping down to the point they hit your LVC while under load. LiPo battery voltage will drop when you put a load on them. How much they drop depends on the quality of the cells. For example, my LVC is usually set to 3.4v-3.6v. Usually when I put those batteries that hit LVC back on the charger to storage charge them, they are already at 3.8v.

Third, when your ESC hits LVC, don't run those batteries again til you charge them. You are likely hurting your batteries. Run your car to LVC, then charge the batteries before you run it again.

 

[leyla1989]

Yes I unplugged them straight after use yesterday. For the full six minutes yesterday it ran completely fine , then this morning after two passes it went into lvc.

Battery is brand new from model sport maybe send it back ?

Cheers leyla

 

[WickedFog]

Yes I unplugged them straight after use yesterday. For the full six minutes yesterday it ran completely fine , then this morning after two passes it went into lvc.

Battery is brand new from model sport maybe send it back ?

Cheers leyla

View attachment 159125

No, you don't need to send it back. Charge it and run it.

 

[bill_delong]

3.8V at rest may very well be LVC under load... you need to fully charge the battery and try again

can you reduce the LVC on the ESC?

 

[DavidB1126]

can you reduce the LVC on the ESC?

If you can try to do anywhere from 3.2 to 3.4 volts per cell. That should be good. 3.0 is risking the battery.

 

[leyla1989]

what should I discharge the battery too . Until the cycle finishes ? Or stop it currently is at 15.2v. Been discharging for 110 minutes

Cheers leyla thank you for all the help

 

[bill_delong]

typical storage mode is 3.8v/cell x 4 = 15.2V

so where you're at is fine for storage... doesn't have to be exact, just close

If you set LVC to around 3.4v/cell under load, that will usually get you fairly close to 3.8v/cell at rest to where it may not be necessary to place the battery in storage mode on the charger after hitting LVC

 

[TRAT]

Discharge and balance charge it.

 

[DavidB1126]

I would discharge to 3.2/cell cause under 3.0/cell your really risking the battery. The only time I discharged below 3.0/cell was with my 650 2s for the mini b. (My lowest was 2.74/cell) That might be why my IRs are a little high. (last reading was about 27Ω/cell) But like @bill_delong said 3.8 is the most safest for storing and you are fine at that voltage. Also while balance charging don't exceed 4.20/cell. With my lipos and charger the charging amp rate goes down/slows down when near 4.18 or 4.19/cell.
Lipos hold their charge untill LVC which can be anywhere from 3.0 to 3.6 in the esc settings. After LVC voltage starts to drop very quickly.

 

[TRAT]

Good advice

 

[leyla1989]

So this was at 15.17v on the discharge balance programme . I have now stopped it and goring to fully balance charge it and try it on another run ?
Also I believe the spektrum firma 120 esc doesn’t have an option to alter the vlc

 

[Greywolf74]

So this was at 15.17v on the discharge balance programme . I have now stopped it and goring to fully balance charge it and try it on another run ?

Yes

Also I believe the spektrum firma 120 esc doesn’t have an option to alter the vlc

You are correct. For some reason Spektrum did not add that option to that ESC. Its probably set to either 3.4V/C or 3.6V/C

 

[bill_delong]

So this was at 15.17v on the discharge balance programme . I have now stopped it and goring to fully balance charge it and try it on another run ?
Also I believe the spektrum firma 120 esc doesn’t have an option to alter the vlc

Just to clarify, you do not need to discharge the battery between cycles, you can recharge the battery from any voltage back to full charge, the only time you need to discharge the battery is when you are done and need to put it in storage... hence "storage mode"

 

[leyla1989]

It’s now charged at 4.19 4.19 4.19 4.19 going to try it soon will let you know the outcome

 

[TRAT]

See what happens

 

[WickedFog]

See if this helps (I know this has been said, but I feel it's not getting through)...

Charge your batteries to 4.2v/cell.

Run the RC. If you only run for a few minutes, that's fine. But charge the battery back up before using it again.

If you aren't going to use the battery any more that day, check it on the charger. If it is between 3.7v-3.8v per cell, you're fine to put them away for the day. For my batteries, if I am outside of that range, I will discharge them down or charge them up to that range before I put them away.