Hmmm was not a fan of the lipo shutoff as I had read on other newsgroups it does not play friendly with the MFU's own low voltage cut off.
I opted for the plug in LiPo alarm as below:
http://cgi.ebay.com.au/ws/eBayISAPI....=STRK:MEWNX:IT
It has around a 90dB alarm and can be clearly heard across the track we run at and it is inside the cab of my kinghauler!
As to running with lights and sounds on the MFU, I am using the Venom 5400maH LiPo's and recently we did a show at our Truck & Trailer Expo
and I was running all lights except the foglights, had the volume up fairly loud so the spectators could see and hear and I would estimate 3-4 hours running time.
This was not all at once but over the course of the day and in between running around the display area it was parked with all the lights still on.
There is something to be said for buying the higher rated LiPo's.
Below are the ones I have been using:
http://cgi.ebay.com.au/ws/eBayISAPI....=STRK:MEWNX:IT
Hope this helps.