MR2 Roadster Owners Club

The Workshop => Audio / Security / Electrical => Topic started by: Bumbl3 on September 12, 2015, 09:46

Title: Battery confusion
Post by: Bumbl3 on September 12, 2015, 09:46
I need to buy a battery as i do not have one. ( car isnt running)
But im looking to install a massive sound system next year and i dont want to end up buying 2 batterys as the one i buy now isnt up to the job
Does anyone run, an amp 2x10 inch subs, 6x9s plus door speakers or anything similar. I understand i will need to run  a power cap At the same time.
What battery am i looking at needing, any links or advice will be a massive help
Thanks in advance
Title: Re: Battery confusion
Post by: Anonymous on September 12, 2015, 10:04
I'm near Camberley, and have a good standard battery if you want it, £10 and it's yours.

You can then get your car running and buy the battery you want / need when it comes it to.
Title: Re: Battery confusion
Post by: Bumbl3 on September 12, 2015, 10:29
Thanks meeerrrk, i have my old mr2 battery somewhere in shed. I think, was just thinking buy it a new one,
But which one? Hoping someone has a big soundsytem.
Title: Re: Battery confusion
Post by: Bumbl3 on September 12, 2015, 10:31
Saying that, my old mr2 had
1x 10 inch sub
2 6x9s
An amp
All off a standard battery, if i have a power cap will i need a massive amp battery?
Title: Re: Battery confusion
Post by: Mr X on September 14, 2015, 16:10
Quote from: "Bumbl3"Saying that, my old mr2 had
1x 10 inch sub
2 6x9s
An amp
All off a standard battery, if i have a power cap will i need a massive amp battery?

In one of my mk2s I had 2x 10in subs, 6x9s, x1 300w amp, x1 150w amp, road angel, screens etc and a power cap. all off the standard old battery that came with the car. I had it 2 years without issue before I sold it.

The power cap just stops a large drain on the battery in one hit.... overall drain will be the same.

It's always worth not skimping on a battery... I'd just get a decent one, do the install and see how it runs. With a decent battery and a good alternator, you should be fine.... We probably couldn't fit enough kit in the Mr2 to need another battery anyway!   s:lol: :lol: s:lol:
Title: Re: Battery confusion
Post by: Bumbl3 on September 15, 2015, 22:00
Thanks mr x
I was thinking that, im just terrified of dead battery lol
Title: Re: Battery confusion
Post by: Bumbl3 on September 15, 2015, 22:02
So im guessong i want a high cold starting amp, not a 330 as thats standard i think?!
Title: Re: Battery confusion
Post by: trickyD on October 15, 2015, 14:58
Just curious, why do you think you need a better battery to run your car audio?
Title: Re: Battery confusion
Post by: Bumbl3 on October 21, 2015, 22:20
Sorry for late reply,
I thought if you didnt have a big enough battery for a decent soundsystem, when you turned it on your lights dimmed
Or car goes flat alot
Title: Re: Battery confusion
Post by: JoeCool on October 21, 2015, 22:30
1) You don't need a power capacitor, ever. IT's a sticking plaster.
2) How are you fitting all that stuff in an MR2 anyway?! Ditch the 6x9's, amp up the fronts properly, it'll sound better, take up less space, be just as loud and simpler to install whilst draining less juice.

3) What you actually need if you plan on running a bigger sound system is a large capacity battery. If you plan on running it with the car off for extended periods than a split charging system and a deep cycle (or 'leisure') battery is the way forwards. Like the ones you get in caravans. If you mean a PROPERLY big sound system, then you need to re-inforce the cars charging circuit with an uprated alternator, to generate more amps in the first place. You can also add thicker cables Alt-Battery, BAttery ground - chassis earth, and engine earth-chassis earth to reduce voltage drop across the charging circuit.


Tell us more about what amps and subs you plan on running in what configuration and i can probably point you in roughly the right direction.

IN short: Big battery, re-inforce charging system, simplify the audio system, don't buy a power cap.
Title: Re: Battery confusion
Post by: trickyD on October 21, 2015, 22:48
Quote from: "Bumbl3"Sorry for late reply,
I thought if you didnt have a big enough battery for a decent soundsystem, when you turned it on your lights dimmed
Or car goes flat alot

You only use your battery to start your car.
When the engines running the power comes from the Alternator
Title: Re: Battery confusion
Post by: trickyD on October 21, 2015, 22:49
Quote from: "JoeCool"1) You don't need a power capacitor, ever. IT's a sticking plaster.
2) How are you fitting all that stuff in an MR2 anyway?! Ditch the 6x9's, amp up the fronts properly, it'll sound better, take up less space, be just as loud and simpler to install whilst draining less juice.

3) What you actually need if you plan on running a bigger sound system is a large capacity battery. If you plan on running it with the car off for extended periods than a split charging system and a deep cycle (or 'leisure') battery is the way forwards. Like the ones you get in caravans. If you mean a PROPERLY big sound system, then you need to re-inforce the cars charging circuit with an uprated alternator, to generate more amps in the first place. You can also add thicker cables Alt-Battery, BAttery ground - chassis earth, and engine earth-chassis earth to reduce voltage drop across the charging circuit.


Tell us more about what amps and subs you plan on running in what configuration and i can probably point you in roughly the right direction.

IN short: Big battery, re-inforce charging system, simplify the audio system, don't buy a power cap.

Only if he plans to listen with the engine off. Not many people do that outside of car shows/meets
Title: Re: Battery confusion
Post by: JoeCool on October 21, 2015, 23:30
" If you plan on running it with the car off for extended periods than a split charging system and a deep cycle (or 'leisure') battery is the way forwards. Like the ones you get in caravans."

That's exactly what I said. HOwever, a slightly larger battery with slightly higher CCA won't hurt, even in general use. Because once you overwhelm the Alternators ability to supply current (not hard at idle) you do draw down from the battery - that's when the lights dim.