Will one lipo pack be enough??

[Bluestreak]

hey guys looking for a bit of advice.

I shall be starting to race in 1/10 off road next year and it will be the first time I have raced using a lipo and brushless setup.

I have an Etronix photon 60amp ESC running a 9turn Etronix Photon motor. Using a 5000mah 2s lipo stick pack from vapextech.

My question is can I run all day on one pack just topping it up between races or will the cells performance drop off doing this?