Neu and Mamba Max Combo

[Sower]

Let's see if I can change my decision again. Here's the question:

If the MM runs great on a 4 cell, can you get enough power from a larger mah 4 cell and run it with a Lehner 1950 on a truggy? Rather than having to go 5 cell. I know the 4 is great for a buggy, but since the truggy is bigger I wasn't sure.

What do you guys think?:eek:

[jollyjumper]

you only need 30~35 mph in truggies so you should be good with 4cells.

[Sower]

Originally Posted by jollyjumper

you only need 30~35 mph in truggies so you should be good with 4cells.

Ah, the key word there is "need". I know I only "need" 30-35 mph, but I would like 40-45 mph to be attainable . . . with the right gearing.:005:

So . . . does a larger mah give me that option?

[jollyjumper]

i see, you want it to be fast.
i dont know then.

[riceman]

Voltage is the key. Check out Brian G's Top Speed Calculator. There is no variable for battery Mah rating.

[jollyjumper]

also you can use the motor selector, very helpfull.

[Serum]

Well, the higher the mAh rating of a cell is, at the same given discharge C, the higher the power is the cells can provide.

4S should be enough for 45 mph. use good cells though, if you go maxxamps, go for a 2P setup.

5S will give you a higher voltage (logically) and at a higher voltage, the setup becomes more efficient. you can use 4S of 4000's or 5S of 3200's to get about the same runtime. Hope this makes sense.

[riceman]

Originally Posted by Serum

Well, the higher the mAh rating of a cell is, at the same give discharge C, the higher the power is the cells can provide.

4S should be enough for 45 mph. use good cells though, if you go maxxamps, go for a 2P setup.

5S will give you a higher voltage (logically) and at a higher voltage, the setup becomes more efficient. you can use 4S of 4000's or 5S of 3200's to get about the same runtime. Hope this makes sense.

Good point. This would be assuming you are running at the same speed (i.e. what you are limited to by the track)?:032:

[Serum]

Yes. the same speed is a given. sorry for not mentioning it.

It simple takes an amount of energy to drive at a certain speed.

[BrianG]

I did not factor in mAh because it really does not "directly" affect speed (more on this later); it affects runtime more than anything. And an actual runtime calculation is all but impossible because of the multitude of other factors (drive style, ambient temperature, terrain, wind resistance, drive train resistance, etc).

Now, a low mAh battery can affect top speed indirectly. A low Ah cell usually can't provide a given current without dropping more voltage than a higher Ah/C rated battery can. Example: If you have a 3Ah battery, it's voltage will tend to droop more when drawing, say, 100A. A 10Ah battery will usually have an easier time providing 100A with less voltage droop since the C rate won't be as high. This voltage droop can affect top speed since less voltage is available to the motor/ESC.

This is why I have the ability to select different voltages per cell. You can approximate the droop and then calculate the speed based on that value.

[Sower]

Nice info guys. Thanks.

Well, I think I might be back to the MM/Lehner now, and go with a larger 4 cell pack and just make sure it's a nice cell. Like a Trakpower or something.

[Serum]

For the ~120 bucks they cost in the states, you can't go wrong with the hard cased trakpowers!

[Sower]

Originally Posted by Serum

For the ~120 bucks they cost in the states, you can't go wrong with the hard cased trakpowers!

Yeah, that's true. Is the 4900mah going to be enough though? I wonder if I should look at something like an Enerland closer to 6000mah.

[Sower]

Maybe this one:

http://cgi.ebay.com/Enerland-Lipoly-...QQcmdZViewItem

Although I guess that's only an extra 100mah over the Trakpower. Wow, I feel smart.

[Serum]

Trakpower uses a special grade of enerland cells. they are not 'just' enerland cells.

and since two trackpowers are cheaper, the answer is obvious.. :p