What can i expect out of my Optima Yellowtop??

[Erickramirez 0]

So i just got a brand new optima yellowtop in my g60 and was just wondering how much playing time could i get out of it with my car turned off and still feel confident it will have enough juice to start up?? looked online and couldnt find anything... a friend of mine said he blasted his music in his truck for almost 4 hours fine. all i have in my g60 are 2 10" MTX Subs with a sony 1200w amp and 2 extra 6x9s, how long can i blast my music??? any experiences with optimas??

[sparks 0]

depends on its Ah rating

 

Ah = amps per hour

 

 

hence if your system is drawing 50amp and and your Ah rating it say 150ah you will get 3 hours

before its flat

 

 

someone correct me on this pretty sure thats how it works

 

stu ..

[Erickramirez 0]

i see and how do i know how much amps my system is using up??

[sparks 0]

well your main draw will be your subs are you running your 6x9 off your headunit

 

 

as a rough guess look at the fuse rating on the side of the amp thats max amps can be draw the correct way would be to clamp measure your main power cable with a dc clamp meter and measure the average amps draw over a selection of music

 

heavy bass draws more amps

 

fast dance less

 

best thing to do is carry one of them battery boost packs from haliford (about £70-90) so if you do flattern it you can at least jump it off the pack to get home

 

i carry one anyway such a life saver if you leave you lights on by accident

nothing worst than calling the AA out for a flat battery or runing around to see if someone has jump leads and will give you a jump

 

stu ..

[Erickramirez 0]

cool well my amp uses 15amp fuses so the most it can possibly use up in an hour is 45 right? im not going to be playin my music for any more than 2 hours so 45amps in 1 hour thats pretty good and yeah im running the 6x9s off my head unit, thanks!

[colinstubbs 0]

Don't forget to add the fuse rating for your headunit too!!!!!!!

[Erickramirez 0]

oh thats right ok but wait so basically the way it works is the number on the fuse, lets take 15amps for example, means thats how much it uses PER HOUR? and at full blast?? so if i have an amp and a headunit with fuses adding to a total of 50amps, does that mean that at full blast it will be using up 50amps in 1 hour?? thanks!

[dr_mat 0]

It'll never hit that number, but yes that is the *maximum possible* number that your sound system can draw. So if you have a 50Ah battery it *could* be flat in an hour. And don't forget you'll need at least 30% remaining charge to actually start the car - so knock a healthy margin off.

 

In practice you'll draw nowhere near the limit, because otherwise they would be blowing fuses all the time. As said before the sub amp will draw the most current out of the lot. If it's a 150W amp you can expect it to draw up to about 13 amps. (150 W / 12 volts = 13 amps.) Almost all the time it will be drawing much less than that. My 140w home hifi amp rarely pulls more than about 35 watts even when it's playing "loud" at a party.

 

That said, if you're serious about leaving the sound system on without running the car, you should really buy another battery, or at least a heavyweight battery booster that can start the car on its own.

 

(More technically, "amps" is a measure of the *rate* of consumption, not an absolute quantity, so when you multiply this rate by the amount of time that rate applies for, you get the *quantity* of charge that has been drained from the battery, measured in Ah - "amp hours". This is why batteries charge capacity is printed in amp hours - to make it easier to figure out how long it will last under a given load.)

[Erickramirez 0]

alright i see thanks for explaining it to me i understand now, ill go do somecalculations and see how long i can play some music now (: thanks!

[turlock 0]

Just to add to this you'll also need to uprate your alternator to something a bit more powerful unless you plan charging it manually after play music for a while

 

Does anyone know where to get a bigger alternator for a G60? Stock is a measly 60 amp and I want to go a bit bigger than the 90 amp one's I've seen