E-Maxx w/Novack HV Maxx Question

[Charlotte515]

I have orderes a Novack HV, can I use 2 TP2100 3S1P in parallel?
Together rated at 62 amps continuous, 84 burst. What load will this motor pull? Thanks

[Mr. Constructor]

You could use up to 12 (resp. 14 cells) or comparable in lipo: 3S 1P without any Problems (except the discharge Problem, stop when the first voltage go down is recognised).

if you do not exceed the voltage line, you could even use a 3S 10P pack (will be very high running time ;-) )

but be careful not exceeding the voltage line of 12 cells (some people say the system is able to be used with 14 cells, better not to try 4S lipos then, the voltage spikes in some cases might destroy the esc otherwise)

hopefully it´ll help ya !!

greetings from Hamburg and a happy new year !!

[Charlotte515]

You could use up to 12 (resp. 14 cells) or comparable in lipo: 3S 1P without any Problems (except the discharge Problem, stop when the first voltage go down is recognised).

if you do not exceed the voltage line, you could even use a 3S 10P pack (will be very high running time ;-) )

but be careful not exceeding the voltage line of 12 cells (some people say the system is able to be used with 14 cells, better not to try 4S lipos then, the voltage spikes in some cases might destroy the esc otherwise)

hopefully it´ll help ya !!

greetings from Hamburg and a happy new year !!

Hi Thanks for the resonse but I am new to this. By the voltage line do you mean not to exceed a certian voltage? These are 11.1volt packs. Also how can I determine the actual load from the motor? I do not want to fry the ESC or batteries. I have a whatt meter I use with planes. Thanks again and Happy New Year!

[SpEEdyBL]

I wouldn't worry about harming the esc. The hv maxx handles a maximum of 16.8 volts, so 11.1 volts is fine. However the hv maxx does not have a voltage cut-off, so you will need an external device that cuts power to the esc when the battery voltage drops below 9 volts or 3 volts per cell.

[Charlotte515]

I wouldn't worry about harming the esc. The hv maxx handles a maximum of 16.8 volts, so 11.1 volts is fine. However the hv maxx does not have a voltage cut-off, so you will need an external device that cuts power to the esc when the battery voltage drops below 9 volts or 3 volts per cell.

Thanks for the info, Ok on the esc, what about the motor amp load do you know if it will exceed the ratings on the TP2100's? I guess I will run the stock spur gear and from what I can determine from the threads a 12 to 14 tooth pinion should not overload the esc.

Is there any after market "devices" to mangage the low volt cuttoff. I know there are LED voltage monitors for about $30, but this will have to be visually monitored.

[ElectricThunder]

I wouldn't worry about harming the esc. The hv maxx handles a maximum of 16.8 volts, so 11.1 volts is fine. However the hv maxx does not have a voltage cut-off, so you will need an external device that cuts power to the esc when the battery voltage drops below 9 volts or 3 volts per cell.
The HV maxx is factory rated up to 14 cells. But of course, I'm sure there are crazy people out there that have run over that amount, and the ESC still survived. (the FETs are probably rated to at least 25 volts I'm guessing....:D).

A low voltage cutoff separate from the HV maxx ESC would indeed be needed as well. FMA sells LVCs. Take a look on tower. As for the motor's amp pulling, I think I read that it's a 6.5 turn motor in one of their mini catalogue thingies, so expect some decent spikes (100 amps isn't unreasonable, especially in a bigger truck). Just monitor battery temp, motor, ESC, and gear accordingly.

Edit: Here's a link to an FMA LVC, but it cuts off each cell at 2.5 volts instead of 3.

http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGFS7&P=7

[aqualato1]

This lvc will cut off at 3v http://66.241.195.91/lithium/lithium.asp?path1=lithium
It doesn't totally cut off power but pulses the power to warn you.

[Maxx42]

This lvc will cut off at 3v http://66.241.195.91/lithium/lithium.asp?path1=lithium
It doesn't totally cut off power but pulses the power to warn you.

Are you familiar with that li-saver? I've read that some guys had problems using it where it would pulse on acceleration due to the voltage drop associated with the initial high current draw.

[tcolesen]

Are you familiar with that li-saver? I've read that some guys had problems using it where it would pulse on acceleration due to the voltage drop associated with the initial high current draw.

That is more of a safety feature. Once the pack gets warmed up, it will hold a higher voltage.

[Maxx42]

That is more of a safety feature. Once the pack gets warmed up, it will hold a higher voltage.

I understand how it's supposed to work, and I think it's a great idea, but only if it works properly. Do you use it or something similar? I'm mainly curious because eventually when I do convert over to lipos, I want to run them in a higher end brushless setup.

[aqualato1]

I understand how it's supposed to work, and I think it's a great idea, but only if it works properly. Do you use it or something similar? I'm mainly curious because eventually when I do convert over to lipos, I want to run them in a higher end brushless setup.
When you convert try to get an esc with a LVC feature in it, that would be your safest bet.

On the other hand if you already have a BL setup then get a kokam LiPo that has a "built-in" LVC feature in it already so you don't have to worry about the LVC.

[Maxx42]

I just read another thread that focused somewhat on the lisaver. Nobody had any pulse problems with it except for one guy that mistakenly plugged in a dead lipo to it and it pulsed right away.

http://forums.radiocontrolzone.com/showthread.php?t=185526&highlight=lisaver

I'm still going to research more on other options though. As far as controllers with LVC, some of them work on a percentage based system where they will cut off after the controller senses the battery has used up a certain percentage of power. They do not detect if the battery is low to begin with. That can be avoided if one just checks the battery before using it, but not everyone does this.

I forgot to comment on the kokam scorpion packs that you mentioned. I like that option but are they available in higher cell counts? I understand that you can put them in series (even still use the lvc circuits), but how many can you use together?

[Maxx42]

I have orderes a Novack HV, can I use 2 TP2100 3S1P in parallel?
Together rated at 62 amps continuous, 84 burst. What load will this motor pull? Thanks


Sorry if it seems that I'm highjacking your thread. I don't mean to, but I'm just curious about learning about lipos and I thought that anything that I could add to this thread would benefit everyone.

[tcolesen]

I'm still going to research more on other options though. As far as controllers with LVC, some of them work on a percentage based system where they will cut off after the controller senses the battery has used up a certain percentage of power. They do not detect if the battery is low to begin with. That can be avoided if one just checks the battery before using it, but not everyone does this.

Most controllers that are Lipo compatible will have a programming option for Lipo LVC. The MGM controllers are a good example. They are programmed to cut at 3.1v/cell. The Mtroniks controllers also have this feature, but I have found that they don't cut the motor or slow it down at all.

[Charlotte515]

Sorry if it seems that I'm highjacking your thread. I don't mean to, but I'm just curious about learning about lipos and I thought that anything that I could add to this thread would benefit everyone.

No problem, this is great info

I plan on using (4) TP 2100 3S1p wired in parallel will this work?
I attached a pic someone else posted. The lenght of the leads will need to be modified but this is the idea.

[tcolesen]

If you did what that pic shows, then you would end up with 6s 4200mah. It puts 2 packs in series, and there are 2 of these that are put in parallel.

In my attached pic, the lines are wires (pos. and neg.), and the red blocks are deans connectors. The very top connector is female, and the rest are male. This shows 4 packs put in parallel.

[Maxx42]

Most controllers that are Lipo compatible will have a programming option for Lipo LVC. The MGM controllers are a good example. They are programmed to cut at 3.1v/cell. The Mtroniks controllers also have this feature, but I have found that they don't cut the motor or slow it down at all.

How do they let you know? It seems like only the lisaver circuit or something like it is the only thing that I have come across that will give you a positive sign that the batteries are low. I also read about another form of a lisaver that gives out a loud alarm when the batteries are low, but I figured that when I race with nitros I'll probably never hear it. It's on this forum somewhere, I'll have to look for it.

Here it is.

http://www.rcgroups.com/forums/showthread.php?t=221018

[Charlotte515]

If you did what that pic shows, then you would end up with 6s 4200mah. It puts 2 packs in series, and there are 2 of these that are put in parallel.

In my attached pic, the lines are wires (pos. and neg.), and the red blocks are deans connectors. The very top connector is female, and the rest are male. This shows 4 packs put in parallel.

Which is the best way, I will be using a novk hv-maxx combo?

[Maxx42]

Which is the best way, I will be using a novk hv-maxx combo?

The way he showed you with all 4 packs in parrallel. If you use the setup that you have pictured you will have 22.2v at 4200mah. I believe the HVmaxx can only take up to 16.8v. If they are all in parrallel like tcolesen's pic, you will have 11.1v at 8400mah. That would make for some killer runtime on that motor I'd imagine.

[tcolesen]

How do they let you know? It seems like only the lisaver circuit or something like it is the only thing that I have come across that will give you a positive sign that the batteries are low. I also read about another form of a lisaver that gives out a loud alarm when the batteries are low, but I figured that when I race with nitros I'll probably never hear it. It's on this forum somewhere, I'll have to look for it.

Here it is.

http://www.rcgroups.com/forums/showthread.php?t=221018

That depends upon the controller. The MGM controllers can be programmed to either cut the throttle or decrease motor RPM, or have no cutoff at all. The MGM will cut the throttle at 3.1v/cell on Lipo, and will also cut the motor if you choose to have it do so when using NiMh.

I built that Microscream maybe 6 months back, but its whine is somewhat hard to hear over the motor/tires/gears. It doesn't protect the battery, but only notifies you that the battery needs to be removed. So, if for some reason you didn't hear the Microscream, then you could overdischarge your battery, which could permanently damage it or even cause it to erupt.

[Charlotte515]

If you did what that pic shows, then you would end up with 6s 4200mah. It puts 2 packs in series, and there are 2 of these that are put in parallel.

In my attached pic, the lines are wires (pos. and neg.), and the red blocks are deans connectors. The very top connector is female, and the rest are male. This shows 4 packs put in parallel.

This is close, but since I am going to use th novak HV I guess I need to wire the (4)2100 packs with (2)2100 together in parallel instead of 4. Would this give me two packs at 11.1v, 4200mah with twice the amp rating? Would this be a 2S4P?

[ElectricThunder]

If you have 4 of those lipos, and each is 7.4 volts (2s1p), then wiring two in parallel, and then wiring those two "new" packs (which would then be 2s2p) in series, would give 14.8 volts w/4200mah capacity.

If you have 4 of those lipos, and each is 11.1 volts (3s1p), then wiring two in parallel, and then wiring those two "new" packs (which would then be 3s2p) in series, would give 22.2 volts w/4200mah capacity. This is way too much for the HV maxx. The above choice would work fine.

If you want 11.1 volts, and have 4 of those 3s1p packs, you'd need to wire 'em all in parallel. What tcoleson's diagram looks like is how you should do the 3s4p setup if that's the route you want to go.

[Charlotte515]

If you have 4 of those lipos, and each is 7.4 volts (2s1p), then wiring two in parallel, and then wiring those two "new" packs (which would then be 2s2p) in series, would give 14.8 volts w/4200mah capacity.

If you have 4 of those lipos, and each is 11.1 volts (3s1p), then wiring two in parallel, and then wiring those two "new" packs (which would then be 3s2p) in series, would give 22.2 volts w/4200mah capacity. This is way too much for the HV maxx. The above choice would work fine.

If you want 11.1 volts, and have 4 of those 3s1p packs, you'd need to wire 'em all in parallel. What tcoleson's diagram looks like is how you should do the 3s4p setup if that's the route you want to go.

Ok thanks I think I have a solution.

[Maxx42]

That depends upon the controller. The MGM controllers can be programmed to either cut the throttle or decrease motor RPM, or have no cutoff at all. The MGM will cut the throttle at 3.1v/cell on Lipo, and will also cut the motor if you choose to have it do so when using NiMh.

I built that Microscream maybe 6 months back, but its whine is somewhat hard to hear over the motor/tires/gears. It doesn't protect the battery, but only notifies you that the battery needs to be removed. So, if for some reason you didn't hear the Microscream, then you could overdischarge your battery, which could permanently damage it or even cause it to erupt.


I kinda figured that the siren used in the micro scream would be hard to hear over the running of the rc. You probably wouldn't hear it at all if any nitro vehicles were running nearby.
As far as the MGM controllers go, I don't think they have one available for what I'd like to do (over 18 cells or at least 6cell lipo). That is cool though how they can be programmed to protect Lipos though. Thanks for the info.

[tcolesen]

I agree, the major drawback of the MGM controllers is their low cell limits. The highest CAR one currently out can only handle 16 cells (5s Lipo), but apparently there will be either an 18cell or 24cell version out somewhat soon.

[Mr. Constructor]

They do have a 24 cell version in the planning, it´s not listed on their HP yet, but will soon be avialable for use in big scale 5th card or similar (off course in trucks too)
Amp Rating will be around 150 or more as far as my Infos go.

Hopefully this might have helped a bit . . . ;-)

[papapackard]

The FMA Scorpion packs seem to be a no brainer for the HV MAXX set up.


"The new Scorpion 2s, 14.8v LiPo battery packs are part of a revolutionary new advancement in lithium polymer power solutions for R/C Monster Trucks. When two of our 7.4v Scorpion packs are wired in series to provide 14.8 volts, these high-power LiPo packs are ideal replacements for 12-cell (14.4 volt) NiCd/NiMH batteries. These LiPo packs drive both brushed and brushless motors, and work with any electronic speed control (ESC) that stops the motor on loss of signal. Built-in low voltage cutoff (LVC) prevents cell damage by disabling the signal between the receiver and ESC when either pack drops below 5.8 volts. Multiple restarts enable a driver to bring the truck back to the pits when pack voltage gets low. FMA’s Safe Charge Connector is a key part of the system. It enables the Scorpion 2s charger to monitor individual cells and independently charge each cell to its optimum level. Each of the packs in the Monster Truck configuration require separate Scorpion 2s chargers or the packs must be charged one at a time. Charge protection and the LVC’s discharge protection dramatically improve pack performance and life."

3200 mAh 1p4s (14.8V) lithium polymer battery pack for R/C Monster Trucks
Size: 2 times 130mmH x 45mmW x 23mmT
Weight: 2 times 218 grams
Ratings: 20C / 90%
Outputs: 14.8V Nominal, 3200 mAh, supports up to 60A continuous current
Applications: Replaces any 12-cell (14.4 volt) NiCd/NiMH battery for R/C Monster Trucks, extended run-time

[Maxx42]

They do have a 24 cell version in the planning, it´s not listed on their HP yet, but will soon be avialable for use in big scale 5th card or similar (off course in trucks too)
Amp Rating will be around 150 or more as far as my Infos go.

Hopefully this might have helped a bit . . . ;-)


I just read about that in another thread where you helped someone program the flight esc for his project. If the new controller (land based one) has the same low voltage protection as was stated earlier in this thread, I will definitely be interested in it. I just hope it's available by springtime so I can have it for the entire outdoor season.

As far as the scorpion system goes, I really like the fact that it takes all the guesswork out of taking good care of your lipo packs. I was just wondering if you could combine more than 2 of them in series. If so, that also would be a tempting alternative to take as well.

[Mr. Constructor]

The MGM esc´s, wich are for car use, do have the same software, the new one will definitely have the LVC cutoff integrated too !!
By the way, even the smaller flight esc do offer this LVC setup, MGM takes the software and modifies it for the cathegory the esc should be for, i hope that they finally made the last step: PC Programming for all AND a universal software wich lets you choose in wich mode (car/Boat/heli/plane a.s.o.) the esc should operate.
These many features will be hard to setup via the radio, this is where the PC connection is for !!

[rc addict]

hey papa packard, are the twin lipo packs you described as fast or faster than an emaxx running on 14 cells? if so lemme know cause then ill be highly interested. if it can make an emaxx go faster than when its on 14 cells, im in.

[papapackard]

hey papa packard, are the twin lipo packs you described as fast or faster than an emaxx running on 14 cells? if so lemme know cause then ill be highly interested. if it can make an emaxx go faster than when its on 14 cells, im in.

The short and dirty answer is YES. Lighter, more punch, and slower voltage drop off. Additionaly the prices (http://www.fmadirect.com/Products.htm?cat=32&nid=24) are coming down drastically. Seems to be more in line now with competitors, with none of the maintenace headaches. :cool:

[Maxx42]

The MGM esc´s, wich are for car use, do have the same software, the new one will definitely have the LVC cutoff integrated too !!
By the way, even the smaller flight esc do offer this LVC setup, MGM takes the software and modifies it for the cathegory the esc should be for, i hope that they finally made the last step: PC Programming for all AND a universal software wich lets you choose in wich mode (car/Boat/heli/plane a.s.o.) the esc should operate.
These many features will be hard to setup via the radio, this is where the PC connection is for !!

That's great news. I'm now really looking forward to the release of this new esc. Also that would br awesome if they offered pc programming with it. That would take a lot of confusion out of programming (or add more if they do a poor job on the software ;) ).

[tcolesen]

That's great news. I'm now really looking forward to the release of this new esc. Also that would br awesome if they offered pc programming with it. That would take a lot of confusion out of programming (or add more if they do a poor job on the software ;) ).

The MGM controllers for CARS should be capable of computer programming (physically they are, I believe), but MGM has to do some software writing so that it will work (on the controller end). I suppose I might be behind the game and am unaware that this is out, but maybe Mr. Constructor can verify this.

[Maxx42]

The MGM controllers for CARS should be capable of computer programming (physically they are, I believe), but MGM has to do some software writing so that it will work (on the controller end). I suppose I might be behind the game and am unaware that this is out, but maybe Mr. Constructor can verify this.

That's ok. I've read enough threads to know who the guys are out there that can offer trustworthy info. You definitely know your stuff and any info is appreciated.

[Mr. Constructor]

The car esc´s aren´t PC programmable yet, this should be done within the next months, they wanted it to be done till summer 2006.
However the newer esc´s do have the programming port installed, but it´s not useable till now.

[tcolesen]

Thanks for clearing that up, Mr. Constructor. I did notice that my new MGM 12012 controller has a small port that wasn't on my old one, so I figured that physically it should be capable of being computer programmed (but it isn't since the software doesn't support it).

[papapackard]

... as far as the scorpion system goes, I really like the fact that it takes all the guesswork out of taking good care of your lipo packs. I was just wondering if you could combine more than 2 of them in series. If so, that also would be a tempting alternative to take as well.

:cool:


The Scorpion packs were tested up to 4 in series, making an 8S pack. There should be no limit in parallel configurations, keeping in mind current limitations of the connectors and wire. The ESC and receiver wires are daisy chained through each pack to ensure the LVC works on each pack. The charging must always be done on single pack disconnected from the system. This is due to the common ground of multiple chargers shorting stuff when connected to multiple series packs at the same time.


_____________________________

Visit my Web Hangar at www.gregcovey.com/rc.htm

FMA Direct
Director of Marketing and Promotions

[rc addict]

papa, thanks for the input, now i can start saving and eventually buy! unless i win my 700 bucks selling my 4tec, fw-05rr, and the motor on ebay lol

[Maxx42]

:cool:


The Scorpion packs were tested up to 4 in series, making an 8S pack. There should be no limit in parallel configurations, keeping in mind current limitations of the connectors and wire. The ESC and receiver wires are daisy chained through each pack to ensure the LVC works on each pack. The charging must always be done on single pack disconnected from the system. This is due to the common ground of multiple chargers shorting stuff when connected to multiple series packs at the same time.

That's good to know. I understand how the LVC circuit of each pack connects to each other, I was mainly concerned about how many of the packs could be linked together and still be able to use the LVC circuit. In other words, I was concerned by the possibility of the LVC connections being the limiting factor in how many packs that could be used together. Having the possibility of safely using four of them in series though is great.

[rc addict]

i have one more question however directed at packard, can i buy two 6400mah lithium packs from scorpion and mount both in the emaxx? will i get a much longer run time? they are both rated at 7.4 volts, apparently just more mah. is there anything else to worry about? lemme know the would be results, thanks

[papapackard]

The 6400 packs are just more Mah, runtime. Wire the power up just like you would any other pack, series parallel, for whatever you are trying to acheive, higher voltage or more MAh. The lvc wil just go from pack to pack in a daisy chain. Here are a cople of magazine reviews that ought to clear up many questions.

RC Driver (http://www.fmadirect.com/support_docs/item_1180.pdf)
RC Car Action (http://www.fmadirect.com/support_docs/item_1181.pdf)

Here are the Directions (http://www.fmadirect.com/support_docs/item_1199.pdf) for the Monster truck packs. That product is mearly two 1p2s 3200Mah packs packaged together. If you want the 2p2s 6400 MAh packs, just order two.

[papapackard]

:cool:


The Scorpion packs were tested up to 4 in series, making an 8S pack. There should be no limit in parallel configurations, keeping in mind current limitations of the connectors and wire. The ESC and receiver wires are daisy chained through each pack to ensure the LVC works on each pack. The charging must always be done on single pack disconnected from the system. This is due to the common ground of multiple chargers shorting stuff when connected to multiple series packs at the same time.


_____________________________

Visit my Web Hangar at www.gregcovey.com/rc.htm

FMA Direct
Director of Marketing and Promotions


These are not my words. It was meant to be a quote from a reliable source.
Sorry if there was any confusion. ;)