Larger mah in NIMH, just run time, or more power too?

[Boons]

Hi all,

As above really.

I'm running 3000mah nimh cells and wonder if I would see any less power from a 2400mah nimh that I'm looking at? I know it will be a little lighter, and have read mah is all about run time, but does power come into play here too?

Cheers!

[OneKiwi]

Why not go lipo? That way you get runtime and power

[Boons]

I should have said, only allowed nimh at my club for the minis

[SlowOne]

In theory it makes no difference. Speed comes from voltage, not capacity, so if you reduce the capacity and maintain the same voltage, then you'll notice no difference. In practice...

As the capacity goes down during a run the voltage drops too. When you have lower capacity cells, the voltage goes down further than higher capacity cells. When 1500mAh is taken out of a 2000mAh pack, the voltage has dropped a lot more than when 1500mAh is taken out of a 3000mAh cell.

The other side of the coin is that if you have heavier cells then you need more energy to accelerate the car so you use more capacity from the pack so the voltage drops more. This is not so noticeable as the voltage drop from a lower-capacity pack, but it is there.

If you have the choice, and the weight to take the larger capacity cells, you will keep your speed higher across the race by having a higher capacity cell. If the weight drops greater than 5% from the lower capacity cells (say 1000g down to 950g) then you might not notice any difference. Anything less in the weight-drop numbers and you will be better off taking the larger capacity cells to keep the voltage up across the race time. HTH :)

[CrashBangWallop]

If you are running a mini then you need to get some Sanyo Ni-Cd 1400 SCRC's but as we are in 2013 and not 1994 your best option are the Vapextech 3700mah packs. Over this capacity the weight of the individual cells goes up so much so that a pack of 5000mah weighs almost a 3rd more than a 3700mah pack, its just ballast !
The 3700mah packs need a bit of heat in them to get the best out of them and stick them on a trinity DPD discharger every so often to keep them in top form.