Quote Originally Posted by graeme
We used one of nippers packs in little flipper at the uk champs pulling 500A and there wasnt a problem with the lipos, also ls4 pulls over 6000w at 37v spinning up fast and either packs could run a heavy so if we werent allowed them in heavys then the feather rules should also be looked at as they have less armour to protect them. Big nipper has 300A fuses on each lipo pack and 200A on the motors so if a motor stalled it would blow, so the 1000A lipos would never be stressed. No problem.
OK so you have a 1000A lipo and a 300A fuse, all seems very good with a more than adequate safety ratio.

I had a look up to see if I could get some reasonable time/current characteristics on line. Weren't extensive so i settled for these http://www.littelfuse.com/data/en/Data_ ... aSheet.pdf

If you take a look at page 5 you will see the time/current characteristics of this particular 300A fuse.

Follow the 300A line up and you will note that this is quite capable of holding a 450A load for about 1000seconds.

A 1000A load would take 20seconds to blow this fuse

Now I don't know what fuses you are using but I would suggest that the fuses are similar in terms of their actions. To corrctley size a fuse you need to know what the fault current is for a dead short accross the battery therminals and the time you need to clear the fault in.