Kill switch requierments

[merc-blue]

G'day
after relocating my battery to the boot im looking at what killswitch to use.
what sorta requirerments should i be looking at?
1000A peak(10 second) 50A continuous enough?
or should i need to have a higher continuous rate?
i know the 1000A peak should be fine
Cheers

[roadsailing]

that will be fine

[merc-blue]

just out of curiousity what sorta power is drained/returned while normal running also with lights on and high revving on a higishpower altinator, say a 35A altinator + lights + spirited driving

[slide86]

that alternator doesnt seem like it would pump out heaps. i mean they are using 120a alternators now days.

is this for a carby engine? they dont require as much current.

if you are going to be doing some revs then thats when the alternator will be charging the best, you will probably find thats when the most current will be produced. having the lights on will draw some of that current. the voltage reg is the thing that will regulate the amount that gets charged, so youl will find that unless you have some serious electronic hard ware drawing power, you should be fine with the one you have.

maybe getting it recon will ensure that its will last teh distance

[merc-blue]

yeah its for a NA EFI (ITBs ),
i guess there is a easy way to find out if it will survive is but taking it out and testing it.
I cant see the engine drawing 50A from the battery constantly as the altinator supplys alot of power for the spark and lights etc, on the stock (2T carby) TA22 i can pull the battery out once its running and it survives so the new setup shouldnt draw 50A if that doesnt draw anything
am i thinking along the right direction

[roadsailing]

yes you are, when the engine is running everything is draining the alternator (battery included)

current will be going TO the battery, so the current through the cable will be what the battery is pulling to stay charged plus whatever else you are running, fuel pump, amplifier etc.

this brings an interesting point, if you hit the kill switch, the engine will keep running.

[merc-blue]

not on a EFI engine cause it kills the ECU but on a carby with mechanical fuel pump it should (my stockie 2T keeps going). im putting one in because if i have a crash i want to be able to kill my fuel pumps and engine instantly also i want to see some one steal the car with the isolator switch off and key removed

[WDE_BDY]

No point having a kill switch unless the alternator is only hooked to the battery side of the switch, if hooked to battery side then isolator switch can kill everything which is the whole point of having one.

Callum

[merc-blue]

yeah both the altinator and battery are attached to the kill switch,
about the 2T without the battery i forgot about the altinator attached to the kill switch

[WDE_BDY]

Hehe, being there and done that too. Took me a while to work out why my brothers stockcar wouldn't switch off after I wired it.

[M.J.H]

No point having a kill switch unless the alternator is only hooked to the battery side of the switch, if hooked to battery side then isolator switch can kill everything which is the whole point of having one.

Callum

Thats what I did.

But a 35A alt will be borderline to run everthing i reckon.
Might be best to upgrade the thing to 50+ that way you won't get a flat battery if the stock oneain't up to the job.

[merc-blue]

yeah i was looking at upgrading, but say i get a 60A alt. will the 50A continious kill switch have any problems with that?

[thechuckster]

you should look at the switches used race cars - not just your normal big marine isolator switch, but one that has a second set of terminals that can either cut the alternator output directly, or control a big relay that does the same.

If the switch is not rated above the maximum current output of the alternator, then choose a larger switch.

am not sure why you would use an under-rated switch on such an important device?

[M.J.H]

yeah i was looking at upgrading, but say i get a 60A alt. will the 50A continious kill switch have any problems with that?

If the alt is hooked up to the engine side of things then no but if is hooked up to battery side then yes probably.

like the chuckster says check out the race ones avalible prehaps.

[merc-blue]

checkster the one i have ATM is one that i found in the shed and im not sure were it came from, i figure why pay 70-80 dollars for the same thing,
I could get a 100SSR onto the alternator and this switch on the batter and controling the relay i should be set