Lipo questions

[MMMM]

sounds interesting

[HotnCold]

put me down for one of dem 95 amp mamma jammas - for my XXXS - those nitro guys wont have any idea what hit em - :D

[RC-Monster Mike]

If they work well during testing, I will stock a bunch of them. they sound great and the price should be pretty reasonable as well. They are a couple months away at the least, but summer is a couple months away!

[lipomax]

Get the polyquest packs. I have the 4s3500 packs and they're about 7 cells worth of subCs but can delivery about 1 HP continuous. For stock emaxxes, get the 4s3100 packs. They fit in stock trays and can handle 12C continuous and 16C for 10 second bursts. You can get 4s3100 and get two and parallel them for 6200 mah and peak out around 100 amps w/o too much probs. Great for run time and light weight. I went with 8s3100 and went with a slower motor to lower amperage, reduce heat, increase efficiency. Always use the highest voltage possible, get a slower motor and you don't have to worry about heat again... plus more run time.

[lipomax]

BTW, I can bash for over 20 minutes when running my 6s3100 pack on my emaxx! Bashing means mostly 35 mph in first gear and occasional 50 mph bursts in second gear. :) WAY TOO MUCH SPEED.

[RC-Monster Mike]

I have looked at the polyquest packs and will probably stock them when I pick up a Lipo line. I have some Kokams (2000mah, 15c discharge) that I use in my tc3 (and occasionally in the e-maxx). They are a little light for maxx duty, but I ran them in 6s on an xl2400 and it ran very well for a good bit of time (around 8 minutes before I stopped the run, geared for around 30mph). Eventually I will pick these up, as well as a charger or so capable of charging them.

[lipomax]

I've used the 2000 mah kokam 11.1 volt 15C packs in my TC4 with a Hacker C4012s (3500) geared about 10:1. I've also used 14.8 volt same pack. Those batteries on my TC peak out around 40 amps on a carpet track with rubber tires. Tops speed is 30 or 40 depending on how many cells I'm using - obviously, I'm geared very short (small pinion) so I can reduce amp draws. It makes for a very lightly TC - and because the CG is actually higher, more prone to traction rolling... but lighter so everything seems to react a little faster and crashes don't break as many parts. I don't intend on going more than 4s with my TC4. I did make a 6s pack, but I have yet to use it on my TC4. Besides, beyond 60 mph, it's pretty hard to control. Anybody interested in a Kokam 22.2 volt 2000 mah pack that fits into the stock TC3/TC4 chassis? Never used - I did take it apart and reroute the wires so it would be shorter so it wouldn't cause voltage spikes into the controller and destroy the capacitors.

[lipomax]

BTW, I've pushed one 2000 mah pack and got over 100 amps from it!!!!! I had it in my TC4 with a lehner 1515 5 turn motor (that motor is like 11,000 rpm/volt!!!!) The batteries got damaged by that experimental run so I don't recommend 50C for a 15C pack. :)

[RC-Monster Mike]

I run the basic 4200 in my tc3, with two 11.1 kokams in parallel. It flies and runs for quite a while. I ran the same batteries in series in my emaxx with an xl2400 for a run or so (geared for around 30mph). The runtime was good, the power was great, but I haven't run it like that lately, because I don't want to wreck the batteries (I use the batts in the tc3 normally). How do you like the tc4? It seems remarkably similar to the tc3. Is it worth the upgrade?

[lipomax]

I don't know - I've never had a TC3! I had a pro4 previously and hte TC4 seems to be a little more forgiving to drive and easier to drive out of the box (I could never get used to the one way front diff). The parts quality isn't quite Pro4 - but then again, it's not a factory team. I don't need to run a 4200 in my track - it's only 70 feet by 40 feet. There really is no use going ove r30 mph cuz the track is so small. In fact, when I'm using 4s, it's too fast for that small track. Going 0-40 in 1 second gives incredible torque steer - almost no front traction also. In addition, after about 10 minutes, the diff outdrives start to melt - even if they're REALLY tight to start with. So, now I've got metal outdrives.

Mike, you should really use a smaller rotor motor for TC's. Get a 400 series motor. The "spool up" is way quicker. When comparing the basic 3600 vs. a c4012s, (3500), the Hacker is quicker and more responsive. Same top speed. With 1/10 tc, the limiting factor is traction. There is no way you can put down 700 watts of power to the ground on a 3 lb TC. Doubling up on the batt is definitely a good thing - with the 4200 geared approx 10:1, you'll be pulling about 50 amp peaks. Geared just a tad taller, you'll pull 60 amp peaks easily. Good thing you're doubling up on the 11.1 volts.

[HotnCold]

Well it seems that the time has come for me to prepare for a lipo/brushless for my XXXS graphite TC - Which setup would be a good setup for me - i tend to be a little hard (understatement) on the throttle. I dont want any problems - My track usually has quite a nice long back straight with a couple hairpins in the infield - I have no idea what is what with lipos - I will get all my stuff from Mike - All of your input is welcome......

[RC-Monster Mike]

Young,
I have a hacker c40 8s that I have been thinking of putting in the tc for a while, but I just haven't gotten around to it. I have experienced the same thing as you, though. The smaller motors spool up quicker (same principle works on the e-maxx). I also have similar drive issues with the tc3 (torque steer, hard to hold under pure acceleration). I should be getting some high rpm outrunner motors in soon as well, which will have to be tested, but one motor reaches 7500 rpm/volt. It should fly in a TC!

[lipomax]

Mike, I've had one motor go 11,000 rpm/volt and another go 9,500 rpm/volt. It doesn't matter how fast a motor spins. It'll only spin so fast before it's breaks. Those high KV motors are way less efficient too. The high KV motors are only good if you are absolutely limited to running only with 6 cells or other low voltages. Since you're using lipos, high KV really just doesn't matter - in fact, it'll just run hotter and destroy controllers and batteries.

If you want to run 11.1 volts, get a polyquest 11.1 volt 4400 mah pack. Fits in a standard 7cell location - just a tad taller so you'll have to back up the threads just a little. Or, you can go 14.8 volts 3500 mah. Both packs are the same size. These packs will deliver 1HP easily (700 watts). Just be VERY careful charging them and read about all their safety stuff before you get into it.

[Serum]

talk about high kv motors;

I've got a mini-t with a mamba 8k, it sure is one fun ride, if i had place for a 6S (and if the controller was able to handle it) i would also drop in a 4200



Not a monster, but one fast little bugger.. (on 3 S it is rather quick (understatement))

I run it with the 1650mah maxamps.com 3s packs

[lipomax]

I had a mini T with the Mamba 8000. I ran it 3s and measured top speed at 39 mph with 13 tooth pinion. Definitely fast - but not very controllable due to it wanting to do too many wheelies - so I sold it.