second battery and fusing

[Beatin' 10+ year member]

soon I will have a second battery in the trunk. The fuse for the power cable attached to the battery under the hood is rated 150A. When fusing the power cable for the trunk battery, do I also use a 150A fuse or do I have to divide the amperage rating and get two 75A fuses?

Click to read more...

 

[tc300 10+ year member]

150

 

[NASTY08IMPALA 5,000+ posts]

soon I will have a second battery in the trunk. The fuse for the power cable attached to the battery under the hood is rated 150A. When fusing the power cable for the trunk battery' date=' do I also use a 150A fuse or do I have to divide the amperage rating and get two 75A fuses?[/quote']
U fuse to protect the amperage capacity of the wire..are you using 4gauge ofc?

 

[Beatin' 10+ year member]

U fuse to protect the amperage capacity of the wire..are you using 4gauge ofc?

2/0cca

amp needs a 160A inline fuse but they dont make a ANL 160A so I use a 150A.

So what's it going to be? two 150A or two 75A fuses?

If you hook up two 150A fuses in series, it doesn't become 300A does it?

 

[bbeljefe]

2/0cca
amp needs a 160A inline fuse but they dont make a ANL 160A so I use a 150A.

So what's it going to be? two 150A or two 75A fuses?

If you hook up two 150A fuses in series' date=' it doesn't become 300A does it?[/quote']

The battery fuses aren't there to protect the amp, they're there to protect the wire. Your 2/0 CCA can handle ~350 amps with no problem and I would fuse it at 300. and no, fuses don't add when in series. The reason for having one at each end of the battery wire is that if you have a short in the middle, there will be current flowing from each direction so you need to protect the wire at both ends.

 

[Beatin' 10+ year member]

The battery fuses aren't there to protect the amp, they're there to protect the wire. Your 2/0 CCA can handle ~350 amps with no problem and I would fuse it at 300. and no, fuses don't add when in series. The reason for having one at each end of the battery wire is that if you have a short in the middle, there will be current flowing from each direction so you need to protect the wire at both ends.

****!

So now I need three fuses? 2 between the two batteries and one coming from the trunk battery to the amp? Holy crap.

 

[NASTY08IMPALA 5,000+ posts]

2/0cca
amp needs a 160A inline fuse but they dont make a ANL 160A so I use a 150A.

So what's it going to be? two 150A or two 75A fuses?

If you hook up two 150A fuses in series' date=' it doesn't become 300A does it?[/quote']

It doesnt matter what ur amp takes its not protecting the amp its protecting the wire...u need 300a fuses in all locations where u have 2/0 so yes it sounds like u need 3

 

[Beatin' 10+ year member]

It doesnt matter what ur amp takes its not protecting the amp its protecting the wire...u need 300a fuses in all locations where u have 2/0 so yes it sounds like u need 3

why not 150A?

 

[trumpet 5,000+ posts]

You can use a smaller fuse. Just know that you don't size the fuse based on the fuses built into the amplifier or what the manual says to use.

 

[NASTY08IMPALA 5,000+ posts]

why not 150A?

We just told you ..you are protecting the wire which can carry 300a...you fuse 4ga ofc with 150

 

[Beatin' 10+ year member]

i won't be drawing much over 100A anyway so it doesnt make sense for me to purchase 300A fuses when the wire will never see that.

 

[NASTY08IMPALA 5,000+ posts]

i won't be drawing much over 100A anyway so it doesnt make sense for me to purchase 300A fuses when the wire will never see that.

Once again ...youre fusing has nothing to do with the amp ..get that outa ur head ...its based on wire used ..not amp draw or capapbility or amp fusing ..etc etc

 

[Beatin' 10+ year member]

Once again ...youre fusing has nothing to do with the amp ..get that outa ur head ...its based on wire used ..not amp draw or capapbility or amp fusing ..etc etc

yeah but it's like hitting three birds with one stone.

Since the 150A will not double up when in series, which was my main question, having 150A fuses will protect the wire, amp, and batteries.

......and of course protect the car from burning to the ground.

 

[trumpet 5,000+ posts]

If your MOSFETs in the amp blow it's going to happen too quickly for the amplifier's built-in fuses to protect that kind of destruction. At that level of current draw it's all about protecting the car and the occupants.

Just use the **** 150A fuses if you insist on it. It's better than no fuses or going too large for the wire.

 

[Beatin' 10+ year member]

If your MOSFETs in the amp blow it's going to happen too quickly for the amplifier's built-in fuses to protect that kind of destruction.

There are no fuses on my bk1800 amp. They recommend an inline of 160A.

or going too large for the wire.

that's what I was thinking when other guys started saying 300A. I found it pointless to go that high, even if it is the limit of what the wire can handle.

Now I know what to do.