Second battery or I am good?


AndyGiff

CarAudio.com Enthusiast
Apr 19, 2019
30
0
Fredericksburg, Virginia
Hi everyone, I am currently working on the install for a new system in my 05 civic. I have a Mechman 270 amp alt going in as well as all 0 gauge wires. My primary battery is a optima yellowtop. I will be running 4 amps and a dsp in the trunk.

Amps
Skar 2000.1D running it around 1500-2k watts - for sub
3x Pioneer 8704s - 2 running bridged for a total of 1200 watts, one running 200-300 or so watts - all for my three way setup

I thought I would be ok with the alt and the yellow top but after doing some reading I am not sure if I really need one or not. It would be easier to install now vs later of course, so I wanted to get some more input on the matter. I appreciate any input or answers you guys could give!

Thank you!

Andy
 

BCotrell

Senior VIP Member
May 27, 2015
328
27
irvine, ca
Civic is relatively short, 1/0 is rated close to 600 amps, your alt is 270 so there’s a good amount of power to keep two batteries full and little loss from source to amp. I think the key question is do you plan to show off with your car off for lengthy periods of time? If yes then a rear battery might be good.
 
OP
A

AndyGiff

CarAudio.com Enthusiast
Apr 19, 2019
30
0
Fredericksburg, Virginia
Civic is relatively short, 1/0 is rated close to 600 amps, your alt is 270 so there’s a good amount of power to keep two batteries full and little loss from source to amp. I think the key question is do you plan to show off with your car off for lengthy periods of time? If yes then a rear battery might be good.
Thanks for the reply, I will not really be playing the system with the car off at all, mainly just while driving around. I wanted to make sure I'd be ok with what I have currently. Granted it will not be played at full volume at all times but wanted to make sure when it is, that I don't get large voltage drops and my electrical can handle it without any issues.

Thanks again!

Andy
 

wew lad

wew lad inc
Mar 22, 2015
5,808
77
MA
Civic is relatively short, 1/0 is rated close to 600 amps, your alt is 270 so there’s a good amount of power to keep two batteries full and little loss from source to amp. I think the key question is do you plan to show off with your car off for lengthy periods of time? If yes then a rear battery might be good.
600 amps is a bit of a stretch for 1/0. 400a is the maximum I would recommend telling anyone that 1/0 OFC can handle unless the run is <5 feet. Keep in mind the run isn't just the positive or negative run, it's the entire circuit. From the alternator to the amp and back.

Throw a volt meter on and watch voltage.
Literally this, wire the voltmeter to the amplifier input terminals and see what you get. Ensure that your voltage is within .2vDC whether you measure it from the front of the rear.
 
  • Thanks
Reactions: AndyGiff

BCotrell

Senior VIP Member
May 27, 2015
328
27
irvine, ca
600 amps is a bit of a stretch for 1/0. 400a is the maximum I would recommend telling anyone that 1/0 OFC can handle unless the run is <5 feet. Keep in mind the run isn't just the positive or negative run, it's the entire circuit. From the alternator to the amp and back.


Literally this, wire the voltmeter to the amplifier input terminals and see what you get. Ensure that your voltage is within .2vDC whether you measure it from the front of the rear.
Technically Ur right but my advice wasn’t offin respects to the question. So, Sorry, shouldn’t have said that about 1/0 wire thresholds. With all four of his amps and the config he cited he will be at the highest around 265 amps (2k+600x3). 300 amps at that distance should be within spec of good 1/0. If big 3 is done entire system is 1/0.
 
  • Thanks
Reactions: AndyGiff

Matthew bryant

CarAudio.com Newbie
Jul 18, 2019
8
1
Colorado
600 amps is a bit of a stretch for 1/0. 400a is the maximum I would recommend telling anyone that 1/0 OFC can handle unless the run is <5 feet. Keep in mind the run isn't just the positive or negative run, it's the entire circuit. From the alternator to the amp and back.


Literally this, wire the voltmeter to the amplifier input terminals and see what you get. Ensure that your voltage is within .2vDC whether you measure it from the front of the rear.
are you saying you say from the alternator to the amp and back what exactly do you mean?
 
  • Thanks
Reactions: AndyGiff

wew lad

wew lad inc
Mar 22, 2015
5,808
77
MA
are you saying you say from the alternator to the amp and back what exactly do you mean?
It just means that when you're looking at calculating the wire size for a circuit or run, you need to look at the entire circuit not just the positive or negative side of it. A chart that says 400a is fine for 50' doesn't mean only the positive or negative run should be under 50', it means the entire distance from the alt to the battery and back should be calculated as the distance.

Kind of unnecessary just go with the 400a rule for 1/0.
 
OP
A

AndyGiff

CarAudio.com Enthusiast
Apr 19, 2019
30
0
Fredericksburg, Virginia
Thanks everyone for your input, I really appreciate it. I think when I am wiring everything up I am going to set it up with an option to add an extra battery in the trunk just in case. I think that is probably the best thing to do at the moment until I get all the wire ran and everything hooked up and running, plus it will give me the ability to add more subs later down the road without having to rewire, just in case I want more boom boom. I have a volt meter, was also going to add in one of the constant readers to be able to monitor it all the time as well. Is that Soundqubed one still the fastest reader for the money out there? Oh and yes, it will be the new Mechman alt, with big 3 done and using all 1/0 wire back to the distribution block all fused properly after alt to battery, fused at battery going back to a 1/0 spliter to a fused distribution block. I am also using the 1/0 OFC copper from Sky High Car Audio as well as all OFC wire for the other gauges for the amps and speakers, all from SHCA.

Thanks again everyone I appreciate all of your input!

Andy
 

wew lad

wew lad inc
Mar 22, 2015
5,808
77
MA
Thanks everyone for your input, I really appreciate it. I think when I am wiring everything up I am going to set it up with an option to add an extra battery in the trunk just in case. I think that is probably the best thing to do at the moment until I get all the wire ran and everything hooked up and running, plus it will give me the ability to add more subs later down the road without having to rewire, just in case I want more boom boom. I have a volt meter, was also going to add in one of the constant readers to be able to monitor it all the time as well. Is that Soundqubed one still the fastest reader for the money out there? Oh and yes, it will be the new Mechman alt, with big 3 done and using all 1/0 wire back to the distribution block all fused properly after alt to battery, fused at battery going back to a 1/0 spliter to a fused distribution block. I am also using the 1/0 OFC copper from Sky High Car Audio as well as all OFC wire for the other gauges for the amps and speakers, all from SHCA.

Thanks again everyone I appreciate all of your input!

Andy
Either that or the stinger voltmeter even though its discontinued. Wire it directly to the amplifier input terminals and then calibrate it against a known good DMM. There's a pot on the meter for the adjustment.

SHCA OFC is good but welding cable is just as good and quite a bit cheaper for 2/0 which would be the "equivalent" to 1/0 SHCA OFC.

@Popwarhomie has a good link for fuse holders, way higher quality than anything else on the market. I keep forgetting to bookmark it.
 
  • Thanks
Reactions: AndyGiff

Create an account or login to comment

You must be a member in order to leave a comment

Create account

Create an account on our community. It's easy!

Log in

Already have an account? Log in here.


Users Who Are Viewing This Thread (Users: 0, Guests: 1)



Latest posts

Trending topics

Latest classifieds