(Amp Install Q) Fusing my Battery

[vinnym86]

I've got 4gauge wire running from my soundstream to the battery. when i fuse it at the battery, what rating amp do i use? i know 4g will stand up like 150amps. I was talking to tech-support at Crutchfield and they said whatever fuse rating that's on my amplifier, (there are [3] 80amp fuses), that's the rating fuse i need at the battery... really!?

EDIT: sh*t my bad, there are [3] 25amp fuses on my amp.

[ToyTundra]

there is some debate in this:

Some say the fuse should be equal to the maximum current the wire can carry

Others say the fuse shold be the same as the amp's fuses.

I use the first method, or less, so i would use 150A assuming it's not a real long run of wire

[vinnym86]

Originally Posted by ToyTundra

there is some debate in this:

Some say the fuse should be equal to the maximum current the wire can carry

Others say the fuse shold be the same as the amp's fuses.

I use the first method, or less, so i would use 150A assuming it's not a real long run of wire

no, not too long, i'm guess-timating about 15ft at most, even that might be too much. from the trunk to the hood, civic sedan.

thanks for clearing that up. the amp kit i'm buying has a 80amp AGU fuse, but it looks cheap, generic. i dunno, i hear AGU fuses can be of poor quality sometimes. maybe a 150amp ANL would be better?

[PaulD]

Originally Posted by ToyTundra

there is some debate in this:

Some say the fuse should be equal to the maximum current the wire can carry

Others say the fuse shold be the same as the amp's fuses.

I use the first method, or less, so i would use 150A assuming it's not a real long run of wire

the third method (the correct one) is that you are protecting the BATTERY from a short circuit, so you should never exceed the battreries current capacity.

[vinnym86]

Originally Posted by PaulD

the third method (the correct one) is that you are protecting the BATTERY from a short circuit, so you should never exceed the battreries current capacity.

haha, thnx for clearing that up

[ToyTundra]

Originally Posted by PaulD

the third method (the correct one) is that you are protecting the BATTERY from a short circuit, so you should never exceed the battreries current capacity.

arn't batteries capable of 300-550A depending on model?

[PaulD]

that would be a MAX current rating ...... the avg or "RMS" current rating is actually roughly equal to it's reserve rating in minutes - don't ask me how they worked that out.

[germanyt]

There is a manual you can order online that explains everything you ever need to know about impedence, power, amperage, etc., etc. Do a search for Mobile Electronics Certification Program. I'm about to start the course so I can get a part time job installing at a local shop.

[vinnym86]

yup, MECP. i need to start a class for that too.

[PaulD]

I have the MECP manual around here somewhere .... it had a number of mistakes in it (theory wise). I hope the newer ones are a little better.