Capacitor vs. Extra Battery

[Stonecold12321 10+ year member]

I recently got a hold of a 2k watt amp and im looking into capacitors to help not fry my alternator. I keep finding comments and responses saying to just connect another battery to the system.

I personally don't understand the difference between the two options but I think i'd prefer a battery cap more seeing as how it looks a little less shady... in my opinion of course.

So I was just wondering what anybody else thought, maybe convince me to not buy a cap I found and lean more on the extra battery option.

Thanks!

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[UnderFire 10+ year member]

Why you don't need a capacitor - Realm of Excursion

All the info you need about capacitors right there.

For 2k, you should probably have a 60-75Ah AGM battery in the back unless you can fit a large 100+Ah AGM under the hood.

 

---------- Post added at 10:25 PM ---------- Previous post was at 10:25 PM ----------

 

Why you don't need a capacitor - Realm of Excursion

All the info you need about capacitors right there.

For 2k, you should probably have a 60-75Ah AGM battery in the back unless you can fit a large 100+Ah AGM under the hood.

 

[slim2fattycake 10+ year member]

get a secondary 80ah+ agm (group 31 deka 9a31 are cheap) battery in the back.

 

[Bettr n' Revrse 5,000+ posts]

Yep ^

 

[Wingman0121 10+ year member]

Capacitors are only truly useful when your electrical system is already strong enough to support your equipment. Capacitors can smooth out the voltage and provide extra oomph during music peaks.

Capacitors are not useful in SPL comps because it'll end up robbing power from the main batteries to charge itself.

I heard a lot of people having good results with capacitors in a daily system with stock alternators and one/two batteries, but that's only half the story. Yes, capacitors do work as intended in low volume, but it goes downhill as soon as you crank past the point where your demand is more than your electrical system can produce. Your car is pulling power to keep things running, your amps are drawing as much power as it can, and the capacitor is pulling power to charge itself just to be emptied on the next bass hit. The gradual loss of power may not be noticeable since the capacitor is still doing its job of smoothing out voltage, you may not know how discharged your battery is until you try to start the car and it barely engages the starter.

 

[blobb454 10+ year member]

Good thread. Good info. I always knew caps were not the greatest for daily uses on simple set ups. I just never really knew the full story why. Thank you guys!

 

[Gemcoska 10+ year member]

So I read though most of that linked post of why you don't need a capacitor and I get most of it. I guess what i was hoping to see there was how exactly a second battery helps. Anyone want to take a shot at this? Also maybe a dummies guide or a line schematic of how a secondary battery would be wired up in the trunk away from the main battery.

 

[garretttt4 10+ year member]

So I read though most of that linked post of why you don't need a capacitor and I get most of it. I guess what i was hoping to see there was how exactly a second battery helps. Anyone want to take a shot at this? Also maybe a dummies guide or a line schematic of how a secondary battery would be wired up in the trunk away from the main battery.

Can either run + and - from front batt to back batt. Then amp + to + on amp and - to - on amp. Or just + from front batt to back batt and ground back batt to frame. I think that's how it works.

 

[itsblown 10+ year member]

watch this video to visually see what happens when you use a cap

 

[97maxima 10+ year member]

So much fail itt

 

[Gemcoska 10+ year member]

Seems like it really should be Cap vs extra battery vs upgraded alternator

... with the winner being upgraded alternator with a good battery... ?

 

[Gemcoska 10+ year member]

Seems like it really should be Cap vs extra battery vs upgraded alternator

... with the winner being upgraded alternator with a good battery... ?