so how long can i have my lipos plugged in?

[blueb8llz]

i know your not suppose to keep your lipos plugged into your charger or the esc, but how long can you keep it plugged for at the most. reason for asking is because on my nimhs, i usually plug in the batts but have the esc turned off. and then ill drive to my bashing site which is about 10 mins away. and ill just turn the esc on from the outside of my truck, since the batts are already plugged in. so is 15 mins for a lipo plugged into the MMM or charger too long?