This is sorta related to car audio....

This is an example.
When my mate goes to the drive-ins, every 15 mins or so he would start his car up and leave it running for around 2 mins.
Is there any point to this?
He seems to think that this will stop his battery from going flat, but Im sure you'd need to run the car for longer than that to replace the charge lost from using his stereo. Along the lines of 30-60 mins.

Can anyone shed some light?

if it's 2 mins, it wont do anythign cause it takes a lot of power to start the car.

Exactly. Kicking over your starter motor will drain your battery much more than your stereo... Even going for several small trips to the shops etc isnt good
lol "every 15 minutes... "
With a new heavy duty battery I've left my stereo and subs going for hours on end (eg falls festival :) over three days on and off) and my car started no problems. Don't leave things like air con/heater etc on without the engine running though.
When ur engine isnt running and theres no road noise ul find that you hardly need anything to power your stereo for comfortable listening levels, headunits only put out around 20w rms anyway, so with a few watts and no background noise ud have no probs.

To charge up your battery you need to run your altenator for a fair while especially with small altenators. But a better test would be for him to leave his stereo pumping hard and see how long it takes for his battery to lose enough buzz to kick over his starter motor.

Worst case, get a jump off someone... :D

I have a generic Mistu Battery. Black Dimond or some bs and i ran my stereo (HU, 320watt amp, sub, 2 sets of splits) for 20mins and there wasnt enuf power to run the stereo lil own start the car. Was thinking of getting one of those sealed wiz bang batteries but havent got the chance to.

I wondered how it works at drive ins do lots of people get flat batteries?

I turn off the subs at the drive-ins, and run the front speakers off the amp (very strong midbass), and rear 6x9s off the head unit makes lots of noise already. i can run for around 45mins at 3/4 volume before starting the car for 10mins or so.

I was at a drive-in movie last weekend...

I have the standard Black Diamond battery that came with my VRX.

The battery is rated at:

430CCA (Cold Cranking Amps) - The number of amps that the battery can produce at 32 degrees F (0 degrees C) for 30 seconds
85RC (Reserve Capacity - Which is the number of minutes that the battery can deliver 25 amps while keeping its voltage above 10.5 volts)

I was running the following at the drive in:

MOSFET Head unit
D-CLASS MOSFET 2CH AMP running two 12" subs.
MOSFET 2CH AMP running 2 rear speakers
Front splits running off HU.
(MOSFET is a type of power supply, it is more efficient and uses less power)

I ran this for the entire movie (about 2 hours) at half volume with the car on ACC.
The car started at the end of the movie, no problems! :)

As some have already mentioned, there is no point in starting the car to run it for only 2mins. For the amount of charge used to start the car, it would take at least 15mins to re-charge the battery to the same point.

:) man amp your fronts and not ur rears!
You got subs there for bass anyways, rears should just be for fill!
:cool:
Good to have the specs on the battery anyways. I gather its the same black diamond thats in all the later magnas.

:) man amp your fronts and not ur rears!
You got subs there for bass anyways, rears should just be for fill!
:cool:
Good to have the specs on the battery anyways. I gather its the same black diamond thats in all the later magnas.
:clap:

You are exactly right....however, they are only the standard splits that came with the car!
(The rears are currently running through the amp on HP)

When I buy some new splits, I will amp them, then run the rears off the deck! :cool:



Yes, the battery is the same in all 3rd Gen 3.5L magnas, not sure about the 3rd Gen 3.0L's though....

My old 2nd Gen 3.0L was definitely different...

Cool, yeh I got a 3.0 litre 3rd gen and its got a black diamond battery, I assume its the same model... I forgot they came with factory splits :) Fairy Nuff. Thats with tweets on the door on that plastic thing where the mirror would usually go yeh. No use running them through an amp anyway...
Do they sound any good? I've never heard them. Or just crappy stock sht.

Cool, yeh I got a 3.0 litre 3rd gen and its got a black diamond battery, I assume its the same model... I forgot they came with factory splits :) Fairy Nuff. Thats with tweets on the door on that plastic thing where the mirror would usually go yeh. No use running them through an amp anyway...
Do they sound any good? I've never heard them. Or just crappy stock sht.
Yeah....the tweeters are mounted on the doors, on the inside of the delta mould (Pic attached)

They actually sound OK for standard speakers, I suppose that is one of the reasons I haven't rushed out to buy new ones yet! :)

I was running the following at the drive in:

MOSFET Head unit
D-CLASS MOSFET 2CH AMP running two 12" subs.
MOSFET 2CH AMP running 2 rear speakers
Front splits running off HU.
(MOSFET is a type of power supply, it is more efficient and uses less power)


Nope - mosfet is a type of transistor - Metal Oxide Semiconductor Field Effect Transistor - it is used in power supplies because it is a field effect transistor, and thus relies on the field effect (capacitance) rather than current for switching - meaning that you use less current to 'hold' the switch closed, and a lower on resistance (meaning less losses in heat)

Cheers
Heath Young

Yeah....the tweeters are mounted on the doors, on the inside of the delta mould (Pic attached)

They actually sound OK for standard speakers, I suppose that is one of the reasons I haven't rushed out to buy new ones yet! :)

wonder if that mould would fit on a 2nd gen....... *ponders*