Well, it all depends on the amp draw... you should not try to (and will not) get the full 200mAh from it no matter what rate you draw from it (maybe 80%.... 160mAh).... so if the amp draw is 2A it will last less than 5 minutes... if it is 6A... maybe a minute and a half.... and so on.
http://www.amainhobbies.com/product_...25C-37V-200mAh