13 replies to this topic

[jam2005]

Currently in my mini ive got four JBL 6x9's, two JBL tweeters and a 1000w JBL sub all running off my 6-Channel JBL Amp and Pioneer head. There running at a total power of 2500 watts. If I play music loud for about 30 minutes the battery is as dead as a fart. This is because the ICE is sucking 90 Amps. I know that I need a power cap and I have heard that 1 Farad is for 1000 watts. Is this right? If so I need a 2.5 or greater Farad power cap?!?!

Please help.
Jam2005 :grin:

[Jordie]

Or set stereo to only work with engine running....then u wont flatten battery unless ur alternator is poor.

[jam2005]

I do that, lol but it still flattens the battery !! The ICE is suckin' 90 Amp max and the alternator is only putting 55 Amp in the battery max. Don't really want to have to get a 100 Amp alternator :sad:

Jam2005 :grin:

[Alex1380]

thats big power drain. try a stonking grate battiey biggest one you can fit in the hole. then you can buy big alernators from mini trailer i belive which is a 155amp. but u willl need to upgrade all you cabling. i run a 900watt 4 channel and a 500watt mono block with out a problem, also with out a cap, which i am thinking about.
Alex.

[Brawlyrox]

when u say ur running 2500w im guessing thats peak power as 2500w rms is ALOT, im pretty certain u will get away with a 1.5 farad cap as u r only running a lower rms rating.

[Madmax]

a 1 FARAD power capacitor wouldnt be enough for 2500w RMS, if its peak power youve calculated that means nothing, look for the RMS of everything and re-calculate.

as for the battery, buy a higher power battery, like a yellow top, and rig it up so that it gets charged off the alternator along with the battery that starts the engine, two power caps would be just as expensive

[Madmax]

and as alex has said, upgrade your altenator

[jam2005]

Just bought a 1.5 Farad power cap. I'll see how that performs and hopefully I wont need to upgrade anything else :erm: . 1 more question, as always......Is this how I wire it up? (parallel to the amp)

Cheers,
Jam2005 :grin:

[Alex1380]

i thought u ran them in the power line. i will ask at work today. as i've just bought one to.

[Madmax]

it goes"

battery > cap > amp

[Pavel]

Pretty sure caps have to be wired in parallel

Also a) there is no way that your system is putting out 2500w rms through 6x9's and a sub (tweeters use up negligible power)
and B) If it WAS, it would be around 200 amps, not 90 (how did you do your calculations? )

That cap should help you with your bass, nothing else... If your battery or electronics seem to die quickly, replace alt as been said above with a powerful one, but they aint cheap!

[jam2005]

I thought that you always wired the power cap up parallel to the amp. That way it acts as a small second battery for the ICE :erm: .

p.s. Pavel the install is 2500w peak power, not RMS. I wish

Cheers,
Jam2005 :grin:

[TimS]

whats the indervidual rms ratings? by the sounds of it a cap wont make any difference to the longertivity of your battery, a cap wont produce any more power for you and is discharged in seconds, it is only momentary peaks of power demanded by the amp. I would give an extra 10 mins at the most to ur batteries life just fior the few seconds it will give ur alternator a chance to add a little more power!

to me by the sounds of it you dont have a very good battery or alternator! if i was you i would run at least a calcium and as big as u can fit in the battery box!


a better way of sorting ur problem than getting a cap is to get a yellow top, thesebattierais are sillily powerfull and really depednign on how long u leave ur system on full wack will last u alot longer and give ur alternater a buetter chance of recharging

[jam2005]

Hopefully the power cap will be here early this week. Going to halfords tonight so hopefully I can get a calcium battery aswell. When heard theres a 20% sale on, on all batteries. So if anyone else wants a battery nows the time to get one.

With the calcium battery and 1.2 farad power cap I rekon (hope ) that its going to cure the problem. If not 100 amp alternator, yellow top battery and a new wiring loom will have to be ordered . Ouuuuchhhhhhh!! :nugget: .

Cheers,
Jam2005 :grin: