Vorteks Vorteks ESC and Battery investigation

[Mark83]

Hello all! If you haven't seen my introduction post I'm a newb here so go easy on me! I purchased a Vorteks and am having a blast with it but noticed very short run times with my Socokin 6600mAh battery so I did a little investigating.

Here's a link to the battery I tested. When I bought it last week it was $41.89 for two of them. I soldered on a EC5 connector.
Link deleted - Not sure if that would be a forum violation and I want to be careful as this is my 2nd post!

After fully charging to 4.2V I got 10 minutes 10 seconds run time. Half grass, half asphalt, not going extremely hard. After resting the battery for 10 minutes it showed a charge of 3.73 volts on each cell. That seemed quite high to me for a LVC value. I charged the battery back up to 4.2 volts and only 2525 mAh was required to charge the battery. Less than half of the rated capacity. Okay maybe I got ripped off and they rated the battery on a "death cycle" from like 2.8 volts to 4.4 or something crazy.

I set the ESC into NiMH mode to effectively disable the LVC. As you know the Vorteks ESC has no LVC programmability.

Using a multimeter I ran the car, all grass, quite hard for 10 minutes, checked voltage, ran a few more minutes, checked voltage, etc.. I didn't write those voltages down. But I did stop the timer each time I stopped to check voltage of the battery pack (with a multimeter). The car ran for 17 minutes this time and the cell voltage was about 3.2. I didn't want to go any lower for fear of damaging the ESC and/or battery. 10 minutes later after plugging it into the charger the rested voltage was 3.33 volts/cell.

Next I charged the battery and what do you know? 6054 mAh went into that battery. Only 10% less than the rated capacity. I also took voltage and mAh readings during the charge cycles as I was very curious as to the charging behavior. You can see my graph below.

My conclusions are as follows. As I wrote above I'm a newb, just trying to be helpful. This data is obviously for my battery but I would expect most Lipos to behave in a similar manner but only further testing would confirm or deny that hypothesis.

1. The LVC on my Vorteks is set ridiculously high. Over half of the battery capacity is being wasted.
2. In my opinion a good "rested cell" discharge voltage is about 3.50 to 3.55 volts, which would probably result in a max discharge of about 3.2 or 3.3 volts. Going any lower does not result in any significant storage capacity.
3. Charging to 4.15 volts wouldn't result in a significant reduction in capacity either, that is if you wanted to "baby" your battery.
4. A good portion of the "meat" of the battery capacity, nearly 1/3 of it is between 3.6 and 3.7 volts. The Vorteks LVC completely wastes that zone on the graph. Note that this conclusion assumes symmetrical charge/discharge behavior, which may be completely incorrect but I think is a logical assumption.
5. I charged at 3.0A for a C charging rate of 0.496 (based on 3000/6054 mAh), which would theoretically be 121 minutes to charge. The actual charge time was 125 minutes, which would account for the ramping down of amps at the end of the cycle during the cell saturation at 4.2 volts. It's nice when experiment and theory agree
6. The 2425 mHr charge I obtained with the Vorteks 3.73 V LVC is just about what you would expect if you look at my graph. Meaning if you charged from 3.73 V to 4.0 V from my graph you'd see about 2800 mAh going into the battery, pretty close to the 2525 I measured on my initial test.

Next I e-mailed Arrma tech support and gave them a detailed explanation of my findings. The representative, who was very nice told me the LVC in the ESC is set by the manufacturer and Arrma doesn't know what it is and can't change it. I didn't want to push him because as I wrote he was very nice and it was obvious that this was the extent of his ability to comment on this issue.

Next I ordered a SPMXSE1130 ESC for my Vorteks so I can set my LVC. 10 minutes run time to 17 is a huge jump and it would probably have been closer to 20 minutes had I been running it easier as in my initial test. There are so many things "right" with Arrma that this isn't a huge deal for me. It would be nice if Arrma could make this LVC adjustable through a firmware update. Or perhaps I got an ESC that was programmed incorrectly or is malfunctioning?

 

[slick2500]

The problem isn't the LVC setting on the esc, it is the batteries. The LVC on the esc is doing what it is supposed to do, cutting power when the power output of the battery goes below a set voltage. What you aren't seeing or accounting for is voltage sag, if you ran the battery down to 3.2v at rest I can assure you that under load the voltage of the battery dipped below 3.0v which is not good for the battery. Changing the esc will not fix this issue.

If you don't believe me buy one of those cheap lipo buzzer alarms, turn off the LVC on your esc and set the LVC on the buzzer to 3.4v I can guarantee you it will go off with a resting voltage of 3.7v.

 

[Mark83]

The problem isn't the LVC setting on the esc, it is the batteries. The LVC on the esc is doing what it is supposed to do, cutting power when the power output of the battery goes below a set voltage. What you aren't seeing or accounting for is voltage sag, if you ran the battery down to 3.2v at rest I can assure you that under load the voltage of the battery dipped below 3.0v which is not good for the battery. Changing the esc will not fix this issue.

If you don't believe me buy one of those cheap lipo buzzer alarms, turn off the LVC on your esc and set the LVC on the buzzer to 3.4v I can guarantee you it will go off with a resting voltage of 3.7v.

You may be right but surely the LVC isn't looking for an instantaneous voltage drop. Any protection device from an old fashioned fuse to a circuit breaker is rated not only for a power it can pass, but also for a duration to allow a higher load. Short duration over and under voltage spikes are generally not destructive. Otherwise sudden demand from a motor would trip the breaker or fuse. Being an engineer myself I can't imagine the engineers who programmed the ESC not looking at v/t curves from a variety of batteries under load to develop smart algorithms in the LVC that both maximize the capacity of the battery and protect the ESC and battery. A voltage drop for 2ms is quite different than one sustaining for 500ms. Both would trip a "dumb" LVC or alarm but the first would not harm the battery.

Also, after noticing this issue with my Vorteks I did a quick search and came across lots of threads complaining about this same issue. And many of them swapped out the ESC and it solved their problem.

Finally, the bottom line is that over half of the battery's capacity is unused with the current ESC in my Vorteks. There was no appreciable drop in performance long after the unreasonably high LVC was tripped and the motor shut down. The ESC in my Vorteks is not performing properly. Perhaps it's defective but this can't be the engineered behavior.

Thanks for the reply and advice. I'm still learning and I'll keep researching this issue.

 

[Puddlejumpernva]

How are the internal resistance values on your battery? It seems to me, the higher quality, newer batteries have much lower IRs. My Povway (very cheap) packs show like 14 mohms per cell while my better packs are 2.

 

[morrjr71]

Unfortunately, you are finding out that Spektrum ESCs aren't all that great. I suggest you buy an ESC that has programmable LVC so you can get more out of your batteries. Hobbywing makes an assortment of ESCs that will work with your Vorteks.

 

[Mark83]

How are the internal resistance values on your battery? It seems to me, the higher quality, newer batteries have much lower IRs. My Povway (very cheap) packs show like 14 micro ohms per cell while my better packs are 2.

Using my ISDT Q6 Nano charger, during charging it shows the cells at 1.9, 2.3, and 2.8 milli ohms.

Unfortunately, you are finding out that Spektrum ESCs aren't all that great. I suggest you buy an ESC that has programmable LVC so you can get more out of your batteries. Hobbywing makes an assortment of ESCs that will work with your Vorteks.

Thanks for responding. Well I already pulled the trigger on a Spectrum SPMXSE1130, which does have programmability for the LVC. I'll fool around with that a bit and see how I like it.

 

[Mark83]

I've been doing some research trying to find out more information about not only the LVC voltage, but how long that threshold might be crossed before power is cut to motor.

The only information I have found thus far is in the manual for the Reedy SC600-BL ESC, which states that power to the motor will be stopped if the voltage is below 3.2 volts for at least 2 seconds. Power will not be restored until voltage is above 3.2 volts. This makes sense as it accounts for some Vdroop under load.

 

[morrjr71]

I've been doing some research trying to find out more information about not only the LVC voltage, but how long that threshold might be crossed before power is cut to motor.

The only information I have found thus far is in the manual for the Reedy SC600-BL ESC, which states that power to the motor will be stopped if the voltage is below 3.2 volts for at least 2 seconds. Power will not be restored until voltage is above 3.2 volts. This makes sense as it accounts for some Vdroop under load.

Comparing a Reedy ESC to a Spektrum ESC may not be a good idea: their design specifications might not be the same. Comparing a Hobbwing ESC to the equivalent Spektrum ESC might give you a better comparison because Hobbywing makes some, if not all, of the Spektrum ESCs and motors. I have several Hobbywing ESCs: some of their RTR systems are more like Spektrum in that fewer settings can be changed, but their aftermarket ESCs are generally more programmable (i.e. LVC can be changed).

 

[Mark83]

Comparing a Reedy ESC to a Spektrum ESC may not be a good idea: their design specifications might not be the same. Comparing a Hobbwing ESC to the equivalent Spektrum ESC might give you a better comparison because Hobbywing makes some, if not all, of the Spektrum ESCs and motors. I have several Hobbywing ESCs: some of their RTR systems are more like Spektrum in that fewer settings can be changed, but their aftermarket ESCs are generally more programmable (i.e. LVC can be changed).

Possibly. But I'm looking specifically at the LVC control mechanism and this is the only manufacturer I could find that provides some information on this in the time domain. While there will be component and design choice differences in ESC's, the basic construction and function will be similar. Since the LVC's function is to protect both the ESC and the battery it appears as though Reedy has determined voltage drops below 3.2V for less than 2 seconds are "safe." Obviously the battery used is not part of this equation because they can't account for what battery is used. Is the Reedy ESC more robust in terms of voltage drops than other ESCs? Unknown but I would take and educated guess and say no.

 

[SrC]

You may be right but surely the LVC isn't looking for an instantaneous voltage drop. Any protection device from an old fashioned fuse to a circuit breaker is rated not only for a power it can pass, but also for a duration to allow a higher load. Short duration over and under voltage spikes are generally not destructive. Otherwise sudden demand from a motor would trip the breaker or fuse. Being an engineer myself I can't imagine the engineers who programmed the ESC not looking at v/t curves from a variety of batteries under load to develop smart algorithms in the LVC that both maximize the capacity of the battery and protect the ESC and battery. A voltage drop for 2ms is quite different than one sustaining for 500ms. Both would trip a "dumb" LVC or alarm but the first would not harm the battery.

Also, after noticing this issue with my Vorteks I did a quick search and came across lots of threads complaining about this same issue. And many of them swapped out the ESC and it solved their problem.

Finally, the bottom line is that over half of the battery's capacity is unused with the current ESC in my Vorteks. There was no appreciable drop in performance long after the unreasonably high LVC was tripped and the motor shut down. The ESC in my Vorteks is not performing properly. Perhaps it's defective but this can't be the engineered behavior.

Thanks for the reply and advice. I'm still learning and I'll keep researching this issue.

As @slick2500 stated, yes it is voltage sag of one or more cells that will trigger LVC. Sag is normal up to a certain point.
You never stated what C rating your lipos have. May be a lipo issue. However, that Vortex Firma ESC is crap IMHO. Nothing new here. No control over LVC??? You should not have to run in Nim pack mode. Absolutely use a lipo Alarm if you do. 3.4v/cell is always my target cutoff. No lower.
And ESC LVC is your main problem.
You were very detailed in your analysis. Get a Lipo Alarm to evaluate further. 6600Mah, in theory, sounds like decent enough capacity for the Vortex no doubt. 15 min run time averages is about right for most rigs in stock trim.
Again, what is the advertised C rating for the lipos?
What you see here is very typical with the Vortex. You are not alone.

 

[Adiabatic]

I had the same issue and did a similar investigation. LVC won't kick in on mine until around 3.6V/cell resting voltage if I'm light on the throttle and running on a smooth surface, but kicks in above 3.7V/cell if I'm heavy on the throttle or running on a surface like grass. My Kraton 6s running two of the same packs in series kicks in below 3.6V/cell when running hard, so the problem is likely either the Vorteks ESC LVC programming is relatively conservative (threshold, time below threshold, or both) or the Vorteks power system is creating a larger than usual voltage drop under load and triggering the LVC early. Like you I couldn't find technical specs on this ESC or even a reliable indication of what the LVC threshold is set at from the factory.

I read some time ago that Arrma acknowledged this issue and is going to release a firmware update that adds a programmable LVC feature to the ESC, but it doesn't look like the latest update has it.

 

[PatMarcus172]

I had the same issue and did a similar investigation. LVC won't kick in on mine until around 3.6V/cell resting voltage if I'm light on the throttle and running on a smooth surface, but kicks in above 3.7V/cell if I'm heavy on the throttle or running on a surface like grass. My Kraton 6s running two of the same packs in series kicks in below 3.6V/cell when running hard, so the problem is likely either the Vorteks ESC LVC programming is relatively conservative (threshold, time below threshold, or both) or the Vorteks power system is creating a larger than usual voltage drop under load and triggering the LVC early. Like you I couldn't find technical specs on this ESC or even a reliable indication of what the LVC threshold is set at from the factory.

I read some time ago that Arrma acknowledged this issue and is going to release a firmware update that adds a programmable LVC feature to the ESC, but it doesn't look like the latest update has it.

Yes- I published that and have chased them since. I was hoping it would come out when they re-released the BLX range with the materials change and then again when the Vendetta was released. They still haven't made the change but Horizon Hobby in the UK acknowledge its a real issue.

 

[Mark83]

As @slick2500 stated, yes it is voltage sag of one or more cells that will trigger LVC. Sag is normal up to a certain point.
You never stated what C rating your lipos have. May be a lipo issue. However, that Vortex Firma ESC is crap IMHO. Nothing new here. No control over LVC??? You should not have to run in Nim pack mode. Absolutely use a lipo Alarm if you do. 3.4v/cell is always my target cutoff. No lower.
And ESC LVC is your main problem.
You were very detailed in your analysis. Get a Lipo Alarm to evaluate further. 6600Mah, in theory, sounds like decent enough capacity for the Vortex no doubt. 15 min run time averages is about right for most rigs in stock trim.
Again, what is the advertised C rating for the lipos?
What you see here is very typical with the Vortex. You are not alone.

C rating on my 6600 mAh batteries is 120C. Even if they are over rated that's still a very high rating.

I only ran in Nim mode during that testing run and I was checking the battery voltage quite often near the end.

The problem is a 10 minute run time with a 6600 mHr 120C battery when the LVC kicks in. When I manually run it down to 3.4 V resting I get more like 17 or 18 minutes. ~2500 mAh charge with LVC cutoff, ~6000 mAh charge when I manually cut power checking voltage levels.

New programmable ESC on the way. I'll update when I test it out.

Just so everyone knows... I'm an Arrma fan! Not bashing (pun intended) then in any way. Every manufacturer is going to have little issues that enthusiasts like us are going to want to tweak. In fact, Arrma is sending me a new ESC for my Vorteks in the event that I possibly have a defective one. That's pretty great customer service.

 

[SrC]

I had the same issue and did a similar investigation. LVC won't kick in on mine until around 3.6V/cell resting voltage if I'm light on the throttle and running on a smooth surface, but kicks in above 3.7V/cell if I'm heavy on the throttle or running on a surface like grass. My Kraton 6s running two of the same packs in series kicks in below 3.6V/cell when running hard, so the problem is likely either the Vorteks ESC LVC programming is relatively conservative (threshold, time below threshold, or both) or the Vorteks power system is creating a larger than usual voltage drop under load and triggering the LVC early. Like you I couldn't find technical specs on this ESC or even a reliable indication of what the LVC threshold is set at from the factory.

I read some time ago that Arrma acknowledged this issue and is going to release a firmware update that adds a programmable LVC feature to the ESC, but it doesn't look like the latest update has it.

+1
HH/Spektrum has a problem there for sure. A very bad one that is not addressed or even acknowledged.
And exactly why does it discriminate the Vortex only??? No sense or logic there. To save .005 cents using a Fixed LVC ESC F/W for the Vortex only????? ESC has been effectively "downgraded".
Firma crap! So many Vortex threads in regards to this one issue.
If it were me, I would warranty the ESC with HH and demand an equivalent Non Vortex ESC replacement. I suspect Spektrum is not in any position to invest in any F/W update for this ESC. HH could care less. Calling them and you get a "scripted" response, "This is normal".
I will bet my wife on this.

 

[PatMarcus172]

C rating on my 6600 mAh batteries is 120C. Even if they are over rated that's still a very high rating.

I only ran in Nim mode during that testing run and I was checking the battery voltage quite often near the end.

The problem is a 10 minute run time with a 6600 mHr 120C battery when the LVC kicks in. When I manually run it down to 3.4 V resting I get more like 17 or 18 minutes. ~2500 mAh charge with LVC cutoff, ~6000 mAh charge when I manually cut power checking voltage levels.

New programmable ESC on the way. I'll update when I test it out.

Just so everyone knows... I'm an Arrma fan! Not bashing (pun intended) then in any way. Every manufacturer is going to have little issues that enthusiasts like us are going to want to tweak. In fact, Arrma is sending me a new ESC for my Vorteks in the event that I possibly have a defective one. That's pretty great customer service.

great theyre sending you a new one. they sent one to me too with the same issue. Ive PMed you on this subject.

 

[Mark83]

+1
HH/Spektrum has a problem there for sure. A very bad one that is not addressed or even acknowledged.
And exactly why does it discriminate the Vortex only??? No sense or logic there. To save .005 cents using a Fixed LVC ESC F/W for the Vortex only????? ESC has been effectively "downgraded".
Firma crap! So many Vortex threads in regards to this one issue.
If it were me, I would warranty the ESC with HH and demand an equivalent Non Vortex ESC replacement. I suspect Spektrum is not in any position to invest in any F/W update for this ESC. HH could care less. Calling them and you get a "scripted" response, "This is normal".
I will bet my wife on this.

I think it's a Vorteks only issue at this point because the Vorteks is the only model in the 3s line to have the new electronics.

The non-programmable ESC is a bummer. One because... it's not programmable. And two because it sends a message that Arrma doesn't really think we're responsible enough to set it properly. The second reason bothers me more than the first actually.

 

[SrC]

Vorteks being the most expensive 4x4, excluding the Vendetta On Roads, you have to ask yourself why they down graded that 100amp ESC???? With much lackluster.
Paying more, getting less. Squeezing us hobbyists horribly.
I advise those considering a Vorteks to not do so?? Just me.
I personally and surely would avoid that one. Go with a BR. Even step up to a 6s if money is not the issue.
Research is so important before buying.
HH slipped a bad one in there.
Hope this is not what lies ahead in Arrma's future lineup. Going the way of Traxasss. ( crappy ESC's) That Vorteks body even looks like it wants to be a Trx something. But we all have different tastes.
I know ranting here won't really solve this problem. Sorry.
Just hoping HH sees my posts. Wishful thinking.

 

[Mark83]

Vorteks being the most expensive 4x4, excluding the Vendetta On Roads, you have to ask yourself why they down graded that 100amp ESC???? With much lackluster.
Paying more, getting less. Squeezing us hobbyists horribly.
I advise those considering a Vorteks to not do so?? Just me.
I personally and surely would avoid that one. Go with a BR. Even step up to a 6s if money is not the issue.
Research is so important before buying.
HH slipped a bad one in there.
Hope this is not what lies ahead in Arrma's future lineup. Going the way of Traxasss. ( crappy ESC's) That Vorteks body even looks like it wants to be a Trx something. But we all have different tastes.
I know ranting here won't really solve this problem. Sorry.
Just hoping HH sees my posts. Wishful thinking.

Voting with your wallet is generally the only way a manufacturer "hears" their buyers. I had no idea going in that the Vorteks ESC would have this issue. I'm new so I read some reviews, none of which mentioned the issue, and jumped in. The truck is great but I stand by my investigation that the ESC is flawed in regards to the ESC LVC. What blows my mind a bit is that the representative I spoke with said I'm the first person that has reported this issue. I sent him links to 5 or 6 forum threads regarding the issue. He said he's send me a new ESC. I'm pretty good at detecting dishonesty so either he was telling the truth or is really, really good at deception. I choose to believe the former. Perhaps he was new.

The bottom line for me is that as shipped my Vorteks uses 2525 mHr of a 6600 mAh battery with rested cell voltages of 3.73 volts. Running it down to 3.5 volts resting will bring that usable capacity number to over 5000 mAh. "Houston... We have a problem."

 

[SrC]

@Mark83 ,
I agree with your assessment. You nailed it.
Most will not even notice this issue IMHO.
But if you understand RC well enough it is so obvious of an ESC F/W flaw. It is very labor intensive to redesign and test F/W unless you have a programmer in place ready to handle this post production. Spektrum does not have this capability here in the states. This occurs with the OE supplier of these ESC's. They are subbed out to OE, F/W and all.
Did you speak with a HH warranty rep, or specifically their Tech dept? Just need a different model 100amp ESC. Why with the Vorteks only.

If you go to page 24 of the Vorteks manual ( Troubleshooting) it states:

Short Run Time -"Incorrect ESC battery mode - voltage cutoff too high for the battery you are using -Adjust the battery mode of the unit"

Yet the ESC will NOT offer this adjustment. HH knows this.
I would demand another 100 amp ESC, one that does have this ESC Parameter Adjustment.
The manual is ambiguous. Not correct. And reveals this Flaw/Issue to exist. One that you clearly observe.
This is in plain Black and White print.
You should NOT have to run in Nimpack setting at all, as a work around to the issue. I don't care what anyone says.

Edited.

 

[Mark83]

@Mark83 ,
I agree with your assessment. You nailed it.
Most will not even notice this issue IMHO.
But if you understand RC well enough it is so obvious of an ESC F/W flaw. It is very labor intensive to redesign and test F/W unless you have a programmer in place ready to handle this post production. Spektrum does not have this capability here in the states. This occurs with the OE supplier of these ESC's. They are subbed out to OE, F/W and all.
Did you speak with a HH warranty rep, or specifically their Tech dept? Just need a different model 100amp ESC. Why with the Vorteks only.

If you go to page 24 of the Vorteks manual ( Troubleshooting) it states:

Short Run Time -"Incorrect ESC battery mode - voltage cutoff too high for the battery you are using -Adjust the battery mode of the unit"

Yet the ESC will NOT offer this adjustment. HH knows this.
I would demand another 100 amp ESC, one that does have this ESC Parameter Adjustment.
The manual is ambiguous. Not correct. And reveals this Flaw/Issue to exist. One that you clearly observe.
This is in plain Black and White print.
You should NOT have to run in Nimpack setting at all, as a work around to the issue. I don't care what anyone says.

Edited.

I was in contact with US Arrma Support. I know when I hit a dead end with support regarding an issue like this. He wanted to send me a new ESC and wrote they have no additional info on the ESC from their supplier. Honestly, the whole reason I made the investigation above is because the rep wanted detailed photos of the issue. I provided it. I have the whole e-mail chain but I don't want to "call out" the rep. He was doing his job the best he knew how. Sending a new ESC is something so I let it go.