6s drop off

[BrianG]

If you get ~12 minutes of runtime with 3200mAh cells at 6s, that's an average current of 16A, and an average power of 355w. A bit higher power needed than I would expect, but whatever. Anyway, the burst amperage is probably around 100. That would equate to over a 30C rate burst. At those levels, voltage WILL dip and trip your LVC. The funny thing about the C rating is that they never state at what voltage it will maintain. So, if they rate the cells at 30C, but at a voltage of 3.0v, this would make sense.

Your buggy probably requires around 225w average power. That would mean that 4s 4100Ah pack is running at 15.2A average current, which nets you around 16 minutes of runtime. Bursts are probably a little lower percentage-wise than the truggy due to the smaller/lighter vehicle, more ideal gearing, etc, so figure ~90A. That's 22C. Makes sense to me that it could handle a higher LVC point without early cutoff.

[spcpicard]

Originally Posted by BrianG

If you get ~12 minutes of runtime with 3200mAh cells at 6s, that's an average current of 16A, and an average power of 355w. A bit higher power needed than I would expect, but whatever. Anyway, the burst amperage is probably around 100. That would equate to over a 30C rate burst. At those levels, voltage WILL dip and trip your LVC. The funny thing about the C rating is that they never state at what voltage it will maintain. So, if they rate the cells at 30C, but at a voltage of 3.0v, this would make sense.

Your buggy probably requires around 225w average power. That would mean that 4s 4100Ah pack is running at 15.2A average current, which nets you around 16 minutes of runtime. Bursts are probably a little lower percentage-wise than the truggy due to the smaller/lighter vehicle, more ideal gearing, etc, so figure ~90A. That's 22C. Makes sense to me that it could handle a higher LVC point without early cutoff.

Not sure how much runtime since I've never drove it longer than the 10min main, I didn't even do a practice lap since I just pretty much got it. I'm sure you're right about the cutoff tripping, but the reason I went with 6s on the truggy is because I figured it would pull less amp from what the motor specs were, but any how I will let you know how it goes tomorrow, now I'm off to soldier a deans on the 1/16 mini revo some one just dropped off to me

[spcpicard]

Originally Posted by BrianG

If you get ~12 minutes of runtime with 3200mAh cells at 6s, that's an average current of 16A, and an average power of 355w. A bit higher power needed than I would expect, but whatever. Anyway, the burst amperage is probably around 100. That would equate to over a 30C rate burst. At those levels, voltage WILL dip and trip your LVC.

Just to clarify, I was getting about 11 mins using 1800 mah of the 3200mah pack. And the hyperion pack is rated 30c cont and 50c burst (according to allerc).

[Patrick]

Originally Posted by BrianG

If you get ~12 minutes of runtime with 3200mAh cells at 6s, that's an average current of 16A, and an average power of 355w. A bit higher power needed than I would expect, but whatever.

That's about the average power usage of all the guys I race with. I don't think anyone ever does a proper race with less than 300w average draw, some guys have the odd race with 400w+ draw.

[spcpicard]

heres a pic with the new BCE chassis.

[nl12]

Whats your opinion on the BCE chassis in an electric car?

[spcpicard]

Originally Posted by nl12

Whats your opinion on the BCE chassis in an electric car?

Will be running / racing with it this weekend for the first time, I'll let you know.

[jzemaxx]

Originally Posted by spcpicard

Will be running / racing with it this weekend for the first time, I'll let you know.

How did the BCE chassis do?