Whats the point of a higher mAh in racing?

qatmix · #1 16-09-2008

Hi All

decided to keep using nicads for now, so was just about to buy some 4600 stick packs when I thought what is the point?

These are for racing, and a race lasts 5 minutes, anything 2000mah and over is fine to power my brushless.. I just wonder why everyone seems to value the higher mAh? If I run 3300's they weigh around 90g less than the 4600's so it seems to me that as they output the same voltage etc over 5 minutes (obviously they would drop off sooner, but it makes no difference if its 10 mins or 20 mins) my car will be faster..

Am I missing something?

frogger · #2 16-09-2008

It's a valid point but don't rock the boat, the world will explode and the human race will no longer exist if we race for longer than 5 minutes man!

glypo · #3 16-09-2008

At one of the clubs I go to 10 minute finals are common, sometimes even 10 minute heats as well.

Secondly, the higher capacity and better quality the cells (whether NiCad/NiMH or LiPo) the lower the voltage drop under load. This gives you more performance. It just so happens that the current draw and voltage drop are relational to the capacity, hence with LiPo packs you get C ratings.

i.e. You can draw more current and experience a lower voltage drop on higher capacity cells. And obviously (in particular with NiCad/NiMH) higher capacity packs tend to be the latest technology. A company would have designed 4600mAh cells much more recently compared to their 3200mAh, so you are getting latest technology, thus performance.

As you say, if you have low capacity cells, there is no need to upgrade until your cells die if you are happy with their performance. However, if you were in the market for new cells, or competing in perhaps touring car racing or higher level off-road, you will want to get the best packs (higher capacity) for best performance.

qatmix · #4 16-09-2008

cheers for the answers. I'm just asking as the extra 85g is 7% more weight to my car and the batteries only discharge at 1.17v per cell as opposed to 1.16v. Wouldnt the extra weight negate the extra power?