2 Batteries
- Thread starter Samwyz
- Start date
it depends on how you want the second battery to charge, you can hook them together so they work as one big battery or you can just have the main battery charge the other one. If your worried about your head lights diming and other *poo* like that when your sterio is loud, just go buy a capasitor and hook that up, cheaper and easier you can get the where you buy your sterio stuff. I'm sure Ryan would have a little bit more of a professional answer to add though.
12SHW LANCER
New Member
A second battery works alot better than a cap. A cap is designed to provide the power straight away instead of running through 10 metres of power cable to the battery infront of the car. It's not used to store charge like a battery does.
SyKRyD
Active Member
sorry, this is a bit off topic but.. you'd need to be running a pretty serious system to require two batteries. i'm assuming you've already upgraded your stock one and tried adding a capacitor?
i'm running 4x v12 amps @ 2000wrms+ plus 2x 12" Type-Rs and my optima yellow top keeps up. if you're not running this gear at minimum, then the dual batteries could be overkill.
i'm running 4x v12 amps @ 2000wrms+ plus 2x 12" Type-Rs and my optima yellow top keeps up. if you're not running this gear at minimum, then the dual batteries could be overkill.
12SHW LANCER
New Member
Well buy yourself a yellow top and that will do the job fine!
Yup in a $1500 sound system there's no need for a second battery, just dont leave the system cranking with the ignition off for too long. If headlight dimming is your main concern there's a few things you can look at:
*Make sure your wiring to the amp is big enough (for a decent mono block you'll need atleast 4Gauge, some of the bigger ones are going to need 0 Gauge) - What this does is ensure a minimal resistance in the power wire. Too much resistance results in a voltage drop when the amp is sucking power, which means the amp will need to suck more current in order to get the same power to the sub.
*Make sure your wire from the amp to sub is a decent sized wire, I went from 12Ga to 10Ga wire for my Kicker L7 and the difference was very noticeable. again like the power wire the larger the wire, the more efficient the amp can push power to the sub
*Make sure the earthing point is good: ie make sure it's a clean and unpainted surface with good metal to metal contact, try and keep the ground lead form the amp as short as possible. This minimizes the restistance and keeps the voltage drop down, a reliable ground is also important for the electronics inside the amp to function as they usually reference to ground for signal processing.
*If after looking at this you are still getting dimming then upgrade your battery to something like a Optima Yellowtop, not only do these store more charge (Ampere hours) than a regular battery they also have lower internal resistances, this means they provide a more steady voltage output when they are loaded up. For example a standard battery unloaded may provide 14.6V when the car and alternator is running but when the sub hits full bass the voltage may drop to around say 14V. If it were a yellowtop though the voltage drop wont be asmuch and for example purposes may be still 14.3V under load from the sub.
You'll get alot of people saying that you dont need your battery once your engine is running so a yellowtop wont make any difference, but generally thoser people are noobs. Because an amp for a sub draws fluctuating amounts of power (ie. lots of power when the sub punches and then minimal power inbetween) there is no way the alternator can supply that, it simply doesn't respond fast enough. The power when the sub hits is drawn from the battery, the voltage regulator then realises the voltage of the battery drops and it ups the current output of the alternator to replenish the battery. Just by listening to my exhaust note I can tell that's how my CJ definitely does it.
As for capacitors they still do store power, just not as much as a battery does. The primary role of a power capacitor those is to try and keep the voltage in a circuit steady. When the sub hits full base the voltage drops which in turn makes the capacitor discharge its power quickly so that it keeps the voltage to the amp up. That's probably the easiest way I can really explain it, but summing up it preferrable to upgrade your wiring and battery before you even look at getting a capacitor as they are really a band-aid solution....
*Make sure your wiring to the amp is big enough (for a decent mono block you'll need atleast 4Gauge, some of the bigger ones are going to need 0 Gauge) - What this does is ensure a minimal resistance in the power wire. Too much resistance results in a voltage drop when the amp is sucking power, which means the amp will need to suck more current in order to get the same power to the sub.
*Make sure your wire from the amp to sub is a decent sized wire, I went from 12Ga to 10Ga wire for my Kicker L7 and the difference was very noticeable. again like the power wire the larger the wire, the more efficient the amp can push power to the sub
*Make sure the earthing point is good: ie make sure it's a clean and unpainted surface with good metal to metal contact, try and keep the ground lead form the amp as short as possible. This minimizes the restistance and keeps the voltage drop down, a reliable ground is also important for the electronics inside the amp to function as they usually reference to ground for signal processing.
*If after looking at this you are still getting dimming then upgrade your battery to something like a Optima Yellowtop, not only do these store more charge (Ampere hours) than a regular battery they also have lower internal resistances, this means they provide a more steady voltage output when they are loaded up. For example a standard battery unloaded may provide 14.6V when the car and alternator is running but when the sub hits full bass the voltage may drop to around say 14V. If it were a yellowtop though the voltage drop wont be asmuch and for example purposes may be still 14.3V under load from the sub.
You'll get alot of people saying that you dont need your battery once your engine is running so a yellowtop wont make any difference, but generally thoser people are noobs. Because an amp for a sub draws fluctuating amounts of power (ie. lots of power when the sub punches and then minimal power inbetween) there is no way the alternator can supply that, it simply doesn't respond fast enough. The power when the sub hits is drawn from the battery, the voltage regulator then realises the voltage of the battery drops and it ups the current output of the alternator to replenish the battery. Just by listening to my exhaust note I can tell that's how my CJ definitely does it.
As for capacitors they still do store power, just not as much as a battery does. The primary role of a power capacitor those is to try and keep the voltage in a circuit steady. When the sub hits full base the voltage drops which in turn makes the capacitor discharge its power quickly so that it keeps the voltage to the amp up. That's probably the easiest way I can really explain it, but summing up it preferrable to upgrade your wiring and battery before you even look at getting a capacitor as they are really a band-aid solution....
SyKRyD
Active Member
excellent write up ryan, thanks. even i learned something there. didn't even occur to me to up the wiring between amp and sub.
lol.. without a cap, my voltages drop to 12v when full bass hits. and my set up uses 0 gauge, seriously earthed with the yellow top. forget $1500 setup though - mines more like $10k+
lol.. without a cap, my voltages drop to 12v when full bass hits. and my set up uses 0 gauge, seriously earthed with the yellow top. forget $1500 setup though - mines more like $10k+
Email the pics to me (ryan@auslancer.com) and I'll upload them for you. Not sure why it's not working because I tested it the other day and uploads were working for me! I've also checked your permissions in the Forum's admin and I cant see why it wouldn't let you upload.... :?
SyKRyD
Active Member
it sneaks up on you doesn't it... i don't even think about it. my cousin, who is in melb studying, asked me how much i spent on my car audio. i replied "oh, probably a couple grand". my dad overheard me and shouted out "bullsh*t!!!" from the other side of the workshop. lol. then i thought about it and added it all up and shocked myself. cables alone would be over $1k. the number of head units/subs/amps/speakers i've swapped over or replaced would easily amount $5k.
12SHW LANCER
New Member
I've spent abit money on audio as well.
I've never added it up, and I don't think I want to either.
I've never added it up, and I don't think I want to either.
i couldnt be bothered reading all that coz i kno nothing of speakers, but
even if you arnt getting a 2nd battery this could be useful to someone else
the is a device called a battery splitter which charges your 1st battery with the alternator and when it senses that it is fully charged it directs the alternators current to charge your 2nd battery
obviously your 1st battery is for the cars starting and your second is for your sound system, as it is more important to charge the 1st one up fully all the time fist b4 the 2nd
aparently this gets better charging of the 2 batteries rather than hooking them up parallel (so i have heard)
anyways, just another way of doing it, i have a few friends from my old tafe who did this and it seems like it works real well but i personally havent get the sound system for it
even if you arnt getting a 2nd battery this could be useful to someone else
the is a device called a battery splitter which charges your 1st battery with the alternator and when it senses that it is fully charged it directs the alternators current to charge your 2nd battery
obviously your 1st battery is for the cars starting and your second is for your sound system, as it is more important to charge the 1st one up fully all the time fist b4 the 2nd
aparently this gets better charging of the 2 batteries rather than hooking them up parallel (so i have heard)
anyways, just another way of doing it, i have a few friends from my old tafe who did this and it seems like it works real well but i personally havent get the sound system for it
