HPI brushless 4600 kV versus 5700kV

[novak]

Hi,
I've decided to buy the e-firestorm flux which comes with a brushless hpi 5700kV motor.
In some websites, some say that we can use a 3-cell LiPo on the 5700kV hpi motor - some say 2-cell LiPo is the maximum it can accept.
What do you think of that ?

I'd like to put 3-cell 11.1 volt on it, do you think it is compatible and what Amperage do you recommend ?

If I can only put a 2-cell 11.1 volt, which one is the best in terms of power and performance ?

Finally, is there any specific connector to use with a LiPo battery on the e-firestorm flux ?

thank you so much for your help.:yes:

 

[CharliesTheMan]

A 2 cell with be 7.4 volts, a 3 cell wil be 11.1, isn't that correct?

I just checked the specs on the setup on HPIs website, and it says that it will support 6 or 7 cell nimh and 2 S LiPo.

 

[novak]

A 2 cell with be 7.4 volts, a 3 cell wil be 11.1, isn't that correct?

I just checked the specs on the setup on HPIs website, and it says that it will support 6 or 7 cell nimh and 2 S LiPo.

Well, I know for sure that there are 2-cell LiPo at 11.1V.
Is there a big difference of power/speed between 2-cell and 3-cell ?

 

[CharliesTheMan]

Could you show me the information on the 2 cell 11.1 volt LiPo, because I need to do some research. It's my understanding that the higher cellnumber provides more power and speed because the voltage is higher, so that causes the RPM's to be that much higher.

For example, I have a sidewinder brushless system. I can run a 4600 kv motor with a 3 S LiPo, or a 5700 kv motor with a 2S LiPo. The 4600 with 3 S LiPo is actually stronger than the 5700 kv with 2 S LiPo when you do the math, because the bigger motor wont handle as much voltage.

 

[abadk9420]

I have looked on the net and can not find a 11.1 volt 2 cell lipo pack all 2 cell lipos are 7.4 volts and all 11.1 volt lipos are all 3 cell packs, but if you could show me a 11.1 volt 2 cell lipo pack that would be great because I would like to see it...

 

[SMaxxin]

Well, I know for sure that there are 2-cell LiPo at 11.1V.
Is there a big difference of power/speed between 2-cell and 3-cell ?

Where did you see a 2 cell lipo that is 11.1 volts? I have never seen one.

 

[CharliesTheMan]

Well since I'm fairly new at this electric stuff I thought maybe I missed something, but I see that I'm not the only one thinking like that so I feel a lil better.

 

[abadk9420]

as far as I know all lipo cells are 3.7 volts each at least for the rc aplication, but I could be wrong...

 

[CharliesTheMan]

yea that's what I thought too. It's kinda like a 7.2 volt nimh stick pack. I can't find a way to add another cell and not increase voltage to 8.4.

 

[abadk9420]

Here is a link about lipo batteries http://en.wikipedia.org/wiki/Lithium_polymer

 

[frickenjoey]

If you just wanted to argue for arguments sake I have some A123 size cells that are 6V each. So two cell would be 12 volt. But they are industrial and not what you need for RC. I have to tell ya Novak you are not going to get 11.1 volts out of a 2s pack with out converting the voltage. Doing that you cut your amperage in half and must HAVE a converter to do it. So in short.....3.7v+3.7v=7.4volts or 2s. Sorry no other way to do the math. When the pack has a fresh charge they may even got up to 8.5 volts but that is a long way from 11.1

 

[novak]

If you just wanted to argue for arguments sake I have some A123 size cells that are 6V each. So two cell would be 12 volt. But they are industrial and not what you need for RC. I have to tell ya Novak you are not going to get 11.1 volts out of a 2s pack with out converting the voltage. Doing that you cut your amperage in half and must HAVE a converter to do it. So in short.....3.7v+3.7v=7.4volts or 2s. Sorry no other way to do the math. When the pack has a fresh charge they may even got up to 8.5 volts but that is a long way from 11.1

Thanks everybody for all your answers...so now can I have a 3s lipo on the firestorm flux 5700kv motor...In the "hobbies" web pages you can find both answer so I don't know for sure and I'm asking you guys to try to get a 100% answer.
Or do I have to get a 4600 kv motor?
And what about the connectors?
And do you have a prefered charger and balancer?
Thanks

 

[frickenjoey]

For connectors.....Deans Ultra all the way. I like the Duratrax ICE and the MRC super brain chargers. Both rock solid. If your speed control is sensorless I would look at the Mamba Maxx motors.....they can crank crazy RPMs. Balancer......as long as it works....I have the Apache from Max amps. Seems to work for me so far.