Uphrading Battery, Need 70Ah Or Over

[jrb1512]

Im running two amps and am upgrading the Battery i was going to go for a varta that is from 70ah to 76ah

anyone know what the biggest size i will be able to fit in the one i have on at the moment looks might do slightly bigger one in, its about 230 x 120 x 296

[alfiejts]

If you look up the Battery for the diesel Yaris of your year, that will be a larger capacity and will be the right type and size to fit....

Some of the Battery manufacturer's web sites also list all their batteries with their sizes and fittings. If you measure what size the Battery tray is, the height available and note which way around the terminals are, you can look through their batteries to find one of the size you want.

Here's the varta catalogue

http://www.varta-automotive.com/fileadmin/templates/downloads/en/Folder/Folder_car.pdf

[jrb1512]

ive looked into loads including leisure batteries could get 98ah from one of them but im never going to fit one in its the width i can get the length and height in, ive looked at loads of brands this week.

is a yellow top in the hood going to be enough replacing the current 45ah Battery? im not sure, i will be maxing at 1000rms on the audio, i could run a second Battery in the boot but i dont want to have to wire a Battery from the boot up to the battery in the front and fuse both ends its too much hassle as im going to change to another t sport by november, any suggestions guys? ive heard mixed review about the yellow tops some saying their the best others saying they aint worth the expense and would rather get through 3 lead batteries than go for the yellow top

[jrb1512]

hi just as an update ive removed the amp in the front so just running the one, ive got a yellow top new but its only 41ah the current Battery is 45ah in the front will it be enough power? although its 4ah less than my standard i was going to keep an eye on it with a voltmeter and top up the charger every few weeks

[lancashirecrumbly]

I'm afraid that no one's going to be able to answer your question precisely because it depends on how you drive the car and how much you use the audio when the car is idling or stopped...

Firstly, the two things you really need to know to make a proper decision are the input power consumption of the amplifiers and the output capability of your alternator.

When the engine is running its the alternator that provides the power and as long as that can replace the power that the amplifier is using then it doesn't matter what Battery size you have.

When you are driving at low revs or idling though, or when the engine is off, then you will drain the Battery as the alternator can't produce the necessary output to replace the power used.

Different amps with the same output power will use different input power depending on how they're designed.

I had a look online and found a couple of 1000w amplifiers. One said its input power was 40 amps and the other 50, so that sounds like the "range" to assume they use...

I also had a look online and found a Yaris alternator that said its output was 80amps.

What we still don't know is how much power the Yaris normally uses to power its engine electrics, so we don't know how much of the 80 amps is already used...

My guess would be that if you're driving on a summers day with most of the car electrics turned off, you'll probably be OK.

If you're driving on a winters night, with the headlights on, the wipers on, the heater fan on, then maybe the standard alternator won't be able to provide enough power, but the only way to find out is to fit an ampmeter to monitor whether monitor whther you're adding power to the Battery or draining it...

The battery size then comes into the debate when you realise that the alternator can't cope or when you want to use the audio system with the enging idling or off.

If you're amplifier uses 40-50 amps, then it will drain a fully charged 45ah battery in an hour...

I think you're probably doing the right thing - fit a voltmeter and keep an eye on the voltage - turn the amp off if hte voltage starts dropping and be aware that if you have it on when stationary or engoine off, it will drain the battery in less than an hour.

The other thing you coudl consider is as "automatic" battery charger. I got one for my mother who doesn't have a big amp, but doesn't use the car enough to keep the battery charged. She simply plugs the automatic charger into the cigarette socket whenever the car is parked in the drive and it keeps the battery topped up.

[jrb1512]

hi, many thansk for the reply, yeah ive bought a new Halfords automatic im going to take it off every weekend and charge it to see state of charge as it flips into maintenance mode when fully charged which is what i wanted, i dont have a voltmeter for inside the car so i will have to manually check it from under the hood

[Avanzato]

Take it off, as it remove the Battery from the car?

Why not get one that you leave connected to the car and just plug it in as you need it. Would save you time and hassle. I've got one on my 'toy' car that doesn't get used very often. Look at the ones from CTEK.

I've got this one. XS3600

[lancashirecrumbly]

Take it off, as it remove the battery from the car?

Why not get one that you leave connected to the car and just plug it in as you need it. Would save you time and hassle. I've got one on my 'toy' car that doesn't get used very often. Look at the ones from CTEK.

I've got this one. XS3600

Yup - The CTEK one is the same one that I got my mother.

Gets rave reviews at AutoExpress and I agree with them...

I plugged the charger into the garage so its dry and always on, fitted a longer 12v cable and a cigarette lighter plug and she just plugs it into the cigarette lighter socket when she parks the car in the drive and takes it out when she drives away...