Hacker C40 8L & Master Car Competition Controller

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I just bought a rc10t4 with a Hacker C408L & Master Car Competition Controller. I am only bashing, I will race my friends for fun at most. I want to get some new batteries. The esc says twelve cells, but can the motor handle 12? I am new to brushless so any help is welcome. Also where can I find the best price on 3000 or higher cells for the best price. I would prefer to have custom assembly. However since I am just bashing and mayby going up to 12 cells I do not think I need matched cells. Just cheap gp 3300 0r 3700 or any other suggestions.

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I want a pack for the most possible speed. I can't afford lipo charger and batteries yet either. At least I dont think.

[chilledoutuk]

Hi there i assume your controller is not the new master car as that can only do a max of 3 lipos or 8 cell nimh.

You ideally want to stay below 50k rpm with these motors im not sure what your motors kv rating is but if you want to go with higher cell count then you could get gp2200 cells which are 4/5ths sub c cells.

If your in the US i would defonetly get them here

http://maxamps.com/

even if your not you should consider getting them there as they are cheap well for me they are (ripoff britain lol)

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hackerbrushless.com shows the comp esc as 12 cells right now. there are 2 different ones.

[TimisTim]

Are you talking about the Master 90-O-F5D? I though they had a revised edition of the original car controller, is this it? Why do they sell the F5D and the F5F for the same amount of money, the F5F handles alot more power.

[froy]

Here's a site for some 3300 and 3700: http://www.unipros.com



I just bought a rc10t4 with a Hacker C408L & Master Car Competition Controller. I am only bashing, I will race my friends for fun at most. I want to get some new batteries. The esc says twelve cells, but can the motor handle 12? I am new to brushless so any help is welcome. Also where can I find the best price on 3000 or higher cells for the best price. I would prefer to have custom assembly. However since I am just bashing and mayby going up to 12 cells I do not think I need matched cells. Just cheap gp 3300 0r 3700 or any other suggestions.

[bigsig]

The only master car competitions I have seen are 6-12 cell. I am not sure which version I have.

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Also how many cells can the motor handle?

[chilledoutuk]

ok heres the table of the latest hacker controllers link is to an image on there offcial german site.
ESC Table (http://www.hacker-motor.com/images/drehzahlsteller.gif)

althogh it is in german you can make out the specs of the controllers. The new master car controllers are only rated upto 8 cells or 3s lipo

The Master-b-car-comp Looks like this (http://www.chilledoutuk.co.uk/******/Master-b-car-comp.jpg)

The entire case apart from the bottom is made out of milled aluminium and acts as a big heatsink.

I am not sure if they are available in the usa yet.

[bigsig]

Mine is the old m.c.c. esc that can take up to 12 cells.
My question is can the motor (c40 8l) handle 12 cells?

[chilledoutuk]

i am not sure of the kv rating of that motor but if you can find it out then simply times this value by the combine voltage of your cells (12x1.2v=14.4v).

The max rpm you should not exceede is 65krpm.

for example if your 8l has similar kv to my 8s then as follows on 12 cells

12x1.2=14.4v

5250x14.4v= 75600rpm

therefore i would exceed the rpm limit my about 10k rpm.

Under load it probably would never reach that amount of rpm but if something in your drive train were to break leaving the motor free running then you could easily over rev your motor and your rotor probably would fall apart.

[starluckrc]

3750kv....while you may get by with 12 cells in bursts for speed runs, you may want to keep it under 10 cells for everyday use.

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Ok thank you. Now I need to find the kv rating on the c40 8l. I have been searching and I can't seem to find it though. Mayby some one has a link?

[bigsig]

Well I found these german pages. No English.

http://www.hacker-motor.com/deutsch/c40_drehzahl.html

http://www.hacker-motor.com/deutsch/c40_masse.html

If anyone with more brushless knowledge could please look at this and figure if my kv is listed (c40 8l)

[bigsig]

Thanx so mine is 3750kv? I am so dumb I didn't even see the post from starluckrc. Was to busy googling for the specs. :o

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Oh where can I get 10 cell packs w/o assembling them myself for a good price?
Also am I right that mah will only affect runtime?

If so is 3700cells really double the runtime of 2400's ?

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Any ideas what speeds I can expect with 10 cells? I have an 11 , 15 , 19 pinions. I actually dont know my gearing.

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Opps I mean 13,15,19 pinions.

[TimisTim]

Is the "L" series to much for an t4? I thought it would be better to have a short can. Its not like its a bad thing just mabey to much torque and not enough rpm's. Might be a little sluggish on the wind up. Though you are using it to bash so mabey more torque would be better. I just moved up to an eight turn feigao from a seven because my controller was heating up a little to much for my taste and I had to compensate by switching to a smaller pinion size for lower top speed. I have only used it twice on a borrowed u-force controller while my is in Germany for a workover, and I like it. Just a little slower but I run 10 cells alot and just got some new lipo's one is an 11.1v so mabey this will compensate.

[chilledoutuk]

I think the C40 8s range is recomended for 1/10th useage.
For an offrad truck i think the lehner basic motors might be quite useful.
You could get something like a basic 3100 go with 12 cells which would be easier on the controller and be in the more ideal rpm of about 43k.

[standard_63]

I use a basic 5300 in my T2 and it screams! A 2S 7.4v lipo from maxxamps is less than half the weight of gp3300s, and in the truck it makes a huge difference. And there would be more room for that giant controller.

You don't need a super charger for the smaller packs, and the smaller packs aren't as expensive.

The 8L probably draws more than the basics, but in the small truck it might be ok. I can't see weighing the small truck down with 12cells? 7 cells or 3S lipos seem like that would be insane speed and power, especially for 2x wheel drive.

[chilledoutuk]

I agree 12 standard sub c cells would just too much weight for the t4 putting a lot more strain on the transmission etc etc.
If you can afford the lipos then you could get some 4/5th gp2200 cells with these cells 8 weigh the same as 6 standard cells.

[bigsig]

I was going to follow starluckrc's advice and run 10 cells.
Is that not good?
No I can not afford the switch to lipo yet.
Do 4/5 have 1.2volt?
Would I have half the runtime with 2200 vs. 3700

[chilledoutuk]

10 cells would be more ideal as it would put the max k rpm in the 40's

However i do still sugest that you use gp2200 cells as they wont weigh your car down as much as 10 gp3700 cells.

The duration obviosly will be shorter than if your were to use 10 gp3700 cells.

somone posted a while ago about using 8 of these gp2200 instead of 6 gp3300 cells because of the increased rpm he geared down and whilst having better acelleration he achieved as good runtime as the gp3300.

remeber Power = Current X Voltage
gp3300 = 3.3 x 7.2
= 23.76 watts

gp2200 = 2.2 x 9.6
= 21.12 watts

add in the fact that the system is more effcient at a higher volatage thanks to the reduced current and the run time should be the same.

[tcolesen]

Your watt calculations are a little off.
gp3300 = 30amps x ~1.16v x 6 cells = ~210amps (can go much higher though)

gp2200 = 20amps x ~1.16v x 8 cells = ~186amps (same note)

But there is definately increased efficiency, which lowers amp rates. Also, aren't 8 GP2200's lighter than 6 GP3300 cells? Brushless motors do tend to be most efficient (in cars) at around 40,000 RPMs, so the voltage should be picked to match that.

[chilledoutuk]

I assumed the voltage of the cells was 1.2v just to simplify the calculation the rest is correct.

The 3300 rating of cells is in mah milli amps for an hour.

This is the amount current it could supply for an hour a measurement in effect of the amount of power it stores.

3300mah is 3.3ah (amp hours)

Where did you get 30amps from and what has this got to with the power stored in the nimh cells.

I will let you know that I have studied electronic engineering and electrical principles upto and including degree level so please be clear where you’re getting these ratings from.

Remember that 23.76watts is an hourly rating if you were to use the battery pack up in say 10 mins you would need a battery pack of say 23.76x6 for it to power the car for an hour (this would also be equivalent to the power usage in watts of the system).

For example often a 6 cell gp3300 battery pack lasts about 10mins on my C40 8s.

The average power used (watts) = Stored power /duration hours
= 23.76/(1/6)
= 142.56 watts
This is an average meaning when under heavy acceleration the power drain will be higher than this average and when coasting it will be much higher.

The average current draw would be simple to then calculate: -

The average currant draw (amps) = Power/voltage
= 142.56/7.2
= 19.8 amps

confirm this by simply taking the mah rating of the pack and then dividing by the time in hours the car ran for: -

The average currant draw (amps) = mah/duration in hours
= 3300/ (1/6)
= 19800 mah
= 19.8amps


gp3300 = 30amps x ~1.16v x 6 cells = ~210amps (can go much higher though)

Where do you get this 30amps rating and for how long is this also might I add that current X voltage = power not current as you have specified. Without a time period for your current rating (like amp hours etc) you cannot quantify the stored power in the pack.

As no doubt the true performance characteristics of every gp3300 pack will differ I have decided to use the manufacturer’s cell specs for my calculations. tcolesen you specify 1.16v per a cell my i have cells that can produce 1.18v @ 30amp discharge.

[tcolesen]

The numbers I was using are just more real-world numbers. I chose 30amps, because that is somewhat close to what is actually being used. At 30amps, a GP3300 cell might be discharged in about 6 1/2mins. I made a mistake, I meant that it equals watts. I chose 1.16v for each cell just as an example. So, if your packs supply 1.18v at 30amps, that's 212watts. These batteries are capable of supplying many more watts than that though. In your previous post when I said that your calaculations are wrong, I meant that they weren't what you would actually be using while driving your car.

[chilledoutuk]

That would only be 212watts if the car lasted 1 hour you need to take into consideration that it only lasts a fraction of watt hours units of time.

Basically what your calculation says is that the cells can supply 212watts of power for 6 1/2 minutes.

My calculation says that it can provide ~ 23watts for 1 hour

Using your numbers the total power in watt hours in a pack would be: -

212watts x time in hours = watt hours

212x (1/(60mins/6.5mins)) hours = watt hours

212 x 0.108 hours = 22.896W

I calculated 23.76w/h so in effect my theoretical calculation and your real life calculation match up quite nicely. I’m sure if I used 1.18 it would bring our calculations to within .3 of each other and considering the 6.5mins you quoted is an approximate figure totally acceptable.

So long story cut short we were both right but using different units i was using watt/hours (Industry standard) and you were using watt/6.5 mins.

watts is not the ideal measurement for quantifying stored energy i think joules is more appropriate ill have to look that up as using that would not have allowed for this sill mix-up.

[tcolesen]

That's great that our measurements at least line up well! But we were both getting at 2 different situations, so that is where we clashed. I do believe that amp hours would be a good measurement. The voltage of the battery cannot stay constant, so watts can't really work all that well. Joules... I don't know. I know that I myself would rather not think in terms of them.

[SpEEdyBL]

You're missing the whole point! As you increase the voltage, you need less amps to get the same power. So what the 8 x gp2200s lack in mah, they make up for in voltage. Then you run a lower kv motor that draws less amps which means more runtime less voltage drop and thus, more power in a real life situation.

[chilledoutuk]

no we are not missing the point at all we were arguing about about the quantification of the engergy stored in battery cells.
I realise this obviously as i have already stated that the effciency is increased by using a higher voltage. do you know why though?
i will tell you anyway
The reduction in current sucking on the batteries is counteracted by the cells having a lower capacity so this is not the real reason.

The reason is that the controllers and motors have a on resistance or inductance. The manufacturers do a good job of keeping this resistance as low as possible as the lower the resistance the less power lost due to heat disipation.
Power dissipated= Current squared x resistance

assuming that the amount of power required to acellerate the car at a fixed rate is constant then you can easily use ohms law to calcualte that as the voltage increases the current requitred to deliver a certain amount of power is inversly proportional.

current = Power/Voltage

the resistance of my controller is 0.00044ohms you can therefor calcualte the dispate heat in watts (lost energy) at set currents.

for example @ 20amps

power = I squared x reisitance

= 20squared x 0.00044
= 0.176watts dissipated as heat

@ 30 amps

power = I squared x reisitance

= 30squared x 0.00044
= 0.396watts dissipated as heat

Becuase the relationship between the current and the disipated heat in watts is exponential the improvement in effciency upon electrical systems by running at higher voltages is massive.

[chilledoutuk]

double post ffs

[bigsig]

So I should be pretty safe with 11 cells then? That would be 41250. I want to go with the new gp3700.
How fast do you think I could go with that set up?

[chilledoutuk]

your motor is 3750kv at 11 cells you would be generating 11x1.2v=13.2v then times that by 3750 you get 49500 too high really for everyday use you want really to keep it below 45k to be safe.

[TimisTim]

Ya know if you are going to be dishing out that kind of cash for 3700's and eleven of them at that. Why not go the little extra distance and buy some lipos. Then you could save alot of weight and double your run times for the almost the amount of money you are going to spend buying some gp3700's which are quite pricey to begin with.

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to timistim
maxamps.com has an 11 cell gp3700 for $84.51 or $77.16 gor the ten cell. Those prices include shipping w/ insurance. I already have a nice supernova charger for the nimh's. I also have 6 & 7 cell gp3300 already too.
Don't get me wrong when I have extra $300 to invest in good lipo charger and batteries i probably will. Plus the lipo's keep getting better too.

to chilloutuk,
well mayby I should go with a 10 cell then. I only want this pack for extreme speed when running with nitro trucks. My buddies think nitro is twice as fast, and I would love to beat them in a straight speed run. Most of the time I will be driving with my daughter and her super mini-t. When i run with her I do not need big speed, until she gets her mamba comp x but that will be when we switch to lipo's anyways.(Mayby Christmas if her skills are there)
I will run 19 pinion for top speed against nitros.
The other 95% I will use 13 to max out runtimes since I don,t need crazy speed then.

[bigsig]

BTW any idea what speeds I might see?
Also will the 11 vs 10 cell be a big difference in speed?

[bigsig]

Well it seems on six cells with the 19 tooth pinion I am hitting around 40+ mph. That is assuming my buddies 1/8th nitro buggy is really doing close to 50 mph like he says. It seems he has about 5 mph more top speed than me.
I cannot wait to get my 10 cell pack and see what that does!