Lipo batteries, how many races do you get?

[TheBinarySheep]

I'm looking to buy a fairly inexpensive battery, maybe 3000 mAh, and I can't decide if it'll be enough to last a race? (I've not been doing this long). My current batteries are 4500 mAh, I always charge one while I'm using the other and alternative between the two batteries for each race. One of the batteries is slightly swollen, and has been for a while, so I think it's time I replaced it.

Currently I do club racing, 2wd indoor, 1/10 off-road. I'm using a SkyRC Torro ESC and an Orion 6.5t brushless motor.

I think, that during a 5 minute race I'm using between 800-1000 mAh per race. I'm just wondering what others use per race? Do you use one battery per race, or do you use a single battery for multiple race? or do you charge up between races?

Keen to hear what others do.