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Discussion Starter · #1 ·
Hello all. Got a few questions about trunk mounting a battery.
What are you guys running for setups? This is what I have gathered so far, tell me what you think:
Optima Red Top 75/35 battery, CA 910 CCA 720
25' red 2/0 welding cable
25' black 2/0 welding cable
lug ends for 2/0 cable

I want to run both pos. and neg. cables fron the batt. and tie them into the stock batt. lead with bolted through lug ends. Also sing the Optima I have has both side and top terminal I may run a short ground from the batt. to the chassis in the trunk, just for extra insurance.

I shouldnt need a sealed box for this Optima, should I? Since they are leak proof and supposed to be non-gassing.

To mount it I have some 1"X1" square steel tubbing and 3/8" threaded rod to run through the tubing and floor of the car(backed with big washers).


Tell what you think and/or give me some ideas.

Thanks.
 

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sleeper
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you should put a fuse on the power cable right at the battery.
 

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Yep fuse it with a 250 amp fuse...
Its really only there to prevent shorting out somewhere... 300amp would be better...
Since your in the cold if you have to crank a while you might blow a 200 amp or below..

Chris
 

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70/30 Racing
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i use a 100 or 150 amp breaker (i cant remember). this is nice as you will find yourself tripping it, and 250amp wafer fuses are NOT cheap.

the wiring is plenty, i did the double ground thing too, i just plugged the ground into the chassis in the trunk, then on that same bolt i put another ring connector with another wire and grounded it on the block.
 

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I think Greg Perry blew 150 amp fuses... A breaker should blow also.. Again - you should NEVER blow this fuse.... UNLESS the main power wire grounds - 300amp - buy it once and forget about it, it will never blow until it needs to... (ie the power wire grounding out)

Chris
 

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Discussion Starter · #6 ·
Well, its all in except for a fuse. I have one of those fancy inductive amp meters and I wanted to see how much the car pulls when cranking. It ended up pulling about 270A at ~70 deg F. Looks like I will need at least a 300A fuse. I dont know how much the -30 deg F. weather in the winter here will affect it.
 

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www.FAIRTAX.org
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I have a 250 amp circuit breaker in the SE-R right at the battery. I live in a climate where it gets down to 0* fairly often in the winter. I have never had a problem with the cb tripping no matter how cold it has been. As always, ymmv.
 

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MauiBlueGride said:
I think Greg Perry blew 150 amp fuses... A breaker should blow also.. Again - you should NEVER blow this fuse.... UNLESS the main power wire grounds - 300amp - buy it once and forget about it, it will never blow until it needs to... (ie the power wire grounding out)

Chris
mine only breaks when i try to crank it for more than 20 seconds at a time, and thats probably because the heat is getting so high (heat increases resistance) in the starter that it is drawing a LOT of current.

but, other than that, it never breaks unless i do something stupid, which happens often enough. i also like being able to seperate the battery from the car by simply pushing a button. no unplugging fuses or anything.

another nice thing about this is it DOES break more easily. you can have a very slight ground that wont draw 300 amps, but will start a fire or drain the battery quickly. i think running a small breaker that breaks easily is better than a massive one that wont break for anything short of grounding a terminal.

also, the 150A breaker is cheaper than a 300A fuse and holder, and if it does break, no big deal, just push the button. :D
 

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Veritas
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Sorry I'm late to this one, gang. I do have 250 amp fuses in my relo'd battery setup. I initially bought 125 amp, but popped that one on the first turn. So, I worked my way up until that stopped happening, which was 250 amp. It's been in there 2 years, no pops.

Pat, as for my battery choice I use one of the small Hawker Genesis batteries. It drags a little due to the long + cable length, but otherwise fires right up. I put a charger on it regularly over the winters here, just to be safe.
 

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70/30 Racing
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strange that the 150A fuse should pop so easily, yet my breaker almost never pops unless i crank it for a while. are breakers rated differently than fuses or something?
 

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Breakers/fuses will react differently as far as how long it takes for a draw over the specified current until the fuse/breaker blows.
I don't trust breakers for that reason, and the fact that I and other family members have had them go bad in the house... A fuse to me is a cheap, simple device and I know it will work when I need it to.

Chris
 

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but, if a 150A breaker performs like a 300A fuse, whats the difference? other than the fact that if it blows, you dont have to buy another.

i still stand by my breaker, wafer fuses are NOT cheap.
 

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Define cheap? My car = not cheap, a $3 wafer fuse is reliable as all get out, and to me is cheap. A $40 + breaker is not cheap to me.

My 250 amp fuse will never blow - UNLESS - the power wire grounds out... So whats the point in having a breaker? You shouldn't be blowing the fuse every couple of months anyways. If you continue to blow the breaker multiple times it will eventually wear out - every time you blow it your making the contacts inside that breaker worse and worse and adding more resistance which = less voltage to the starter which = more amps drawn to start the car... A circuit breaker can also fail (like the ones I've had fail at home) and arc weld themselves in the "ON" position - a $3 fuse won't do that and your several thousand dollar car won't burn to the ground because of it..
If someone is that worried about blowing the fuse on accident runa 250 and stick a 300amp in the glove box incase - but again if everything is setup right you'll NEVER have to blow it.

Just my take. I did car audio installs for years, and still work in the car audio industry (for clarion) and in all the expensive demo/dealer/show cars they use fuses - for the same reasons I stated above.... I'd rather have a $3 fuse blow then a $50+ breaker not work and burn my car down, but YMMV.

Chris
 

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MauiBlueGride said:
Define cheap? My car = not cheap, a $3 wafer fuse is reliable as all get out, and to me is cheap. A $40 + breaker is not cheap to me.
where are you getting $3 wafer fuses from? when i went to buy them, they were much more expensive than that. dont forget the fuse holder in the cost as well, or are you just soldiering the wire directly onto the fuse? :D

if i could find $3 wafer fuses, i would have gone this route. i saw the extrememly high price tag and thought of my propensity to pop fuses and got the breaker instead.


MauiBlueGride said:
A circuit breaker can also fail (like the ones I've had fail at home) and arc weld themselves in the "ON" position
i wasnt aware that breakers could do this with the 12V systems we use in our cars. youre saying that your 12V 550 CCA battery can weld a breaker shut before it breaks away? i am curious about this. my friend has been installing high power stereos for a couple of years now, and he hasnt seen this happen in a 12V (or 24V for that matter) car app. didnt think this was something that could happen. oh well.

i pop the breaker because i do some electrical work and forget (or just refuse) to break power (i dont do this as much anymore, as i dont care about losing the 18 billion presets my excelon head unit had, its been replaced by gauges). with the breaker, it wasnt a big deal. my breaker has popped quite a few times (when my car wouldnt start after motor swaps, or because the battery was nearly dead, i would have to crank it for QUITE some time to start it) without a single problem. i am sure i can make it fail, but it has been fathful so far.
 

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Veritas
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That Stinger® fuse holder is precisely what I used in my trunk. I paid a few more bucks for it locally, but hey, guys have to work and earn a living. The fuse was also a few more bucks.

I also *think* that having the longer positive wire certainly adds to the amperage required to start my car. Which may have contributed to popping the 150 amp fuse.

But then again, I'm no Chris Storer. :tongue:
 

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MauiBlueGride said:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=50549&item=3093927210&rd=1

Cheap fuse holder...

Cheap fuse...
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=50551&item=3094664925&rd=1

I buy from the local stereo shop... they give me a pretty nice discount - but $3 is still closer to what they charge everyone else price.


People can run what they want. What I'm saying is - I will not run or suggest breakers.

Chris
well, huh. i stand corrected. where the hell were you when i was pricing all this **** out anyway? :D
 
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