Home Forum Chat Forum How many double 'A' batteries would it take to start a car ?

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• How many double 'A' batteries would it take to start a car ?
• Say a 1.0L Micra or a BMW 750iL

Come on whizz pots how many I ask you I’ve not got a clue !

oh, and they’re cells. you’d put ’em together to make a battery

That as well…

Del
Subscriber

Del
Subscriber

oh, and they’re cells. you’d put ’em together to make a battery. ðŸ˜‰

iolo
Member

five gezillion

Voltage wise, 8 or 9 but you need 300-500 Amps to start a car, which your AAs couldn’t produce. A quick google suggests 2.5A max out of a Durcell AA, so you’d need 200 in parallel for 500A x say 9 to get the voltage, so 1800 or so in 9 series banks of 200 in parallel

stuey
Member

mrlugz
Member

Rough calculations based on brief googlage.

Based on assumption of fresh Duracells (capable of 2A output)

Nissan Micra battery has 550 cold cranking amps, so you’d need to provide that.
so

9X aa duracell in series gives (theoretically) 13.5 volts with 2A current.

550 /2 = 275. so youd need 275 rows of 9 cells to give 550amps

so 2475 AA cells is a 9s275p configuration would start your micra.

A BMW 750 battery has 850CCA, so the configuration would be 9s425p or 3825 AA cells.

This is proper rough guesstimation though. ðŸ™‚

Can you actually get 2A from an AA cell?
Even for a second?

Del
Subscriber

not as rough as mine! ðŸ˜€

mrlugz
Member

winston_dog,

Discharge tests have been done on loads of different AA batteries. The one I looked at showed the Duracell AA supplying 2A for just over 30 mins

Never imagined you would get 2a from an AA! Never mind for 30mins!

fasthaggis
Member

How many AA batteries would you need to supply the OP with the correct amount of Electroconvulsive therapy ?

ðŸ™‚

pondo
Member

Are we just talking in terms of cranking it over, here? Because you’ve got ancilleries to power and spark plugs to spark, too.

maxtorque
Member

What we really need to know is the battery pack equivalent series resistance, so we can calculate the voltage sag vs current output. A typical automotive lead acid battery has a very low ESR, and hence is fairly good at providing the high current/high power but low total energy pulse needed to start an ICE.

In reality, i suspect that you could pull a lot more current than 2A for the 3sec required to start the car, and so need far fewer batteries than the above calcs suggest.

molgrips
Subscriber

A car battery in good nick supplies 550A or whatever, but you can just about start a car with it in worse condition, as long as the rest of the car is in good nick.

maxtorque
Member

I just pulled 3.2A @ 0.86v from a random AA battery found in a drawer, giving a short pulse ESR of 220 mOhm. It easily kept up that output for 5secs. (Cell was floating @1.56v btw)

You need around 10V system voltage during cranking to ensure engine control systems and fuel pumps etc operate (actually, usually, down to ~6v is just about ok, but we will er on the side of caution), so that means 12S156P (1872 cells) for 500A @ 10V.

Mass of my AA cell was 24g, so that’s a battery mass of 44.9kg. Roughly twice that of a typical car battery.

fasthaggis – Member
How many AA batteries would you need to supply the OP with the correct amount of Electroconvulsive therapy ?

POSTED 19 MINUTES AGO # REPORT-POST

Not many

How many AA batteries would you need to supply the OP with the correct amount of Electroconvulsive therapy ?

Brilliant!

Matt24k
Subscriber

Forget AA’s what you need is one of these.
Anti Gravity Jump Starter

The Peugeot / citroen hybrid system is 150bhp engine driving the front wheels and a 50 bhp electric motor powering a small gearbox to the rear wheels, in the boot is a battery case with 150 AA BATTERYS case with an Ecu charging and controller. It’s good for about 2/3 mins of driving before the engine kicks in to recharge it.
But it’s many an emissions benefit. Road tax is Â£10 per year

molgrips
Subscriber

Chris do you own one of those?

Is the car on a treadmill?

maxtorque
Member

chrisdiesel
in the boot is a battery case with 150 AA BATTERYS

I think you’ll find they are 18650 LiPo, not AA! (a big difference in C)

It’s good for about 2/3 mins of driving before the engine kicks in to recharge it

What is the point of that?

Sounds like completely useless “green” technology.

Stand corrected regard the battery’s just what I was told on the training course.maybe just a flippant comment by the trainer.
No I don’t drive one but work on them regularly. Yes the battery size/power could be better but it does it’s job I.e makes the top of the range fully loaded ds5 hybrid in the Â£10 a year tax bracket so company car drivers buy them.

molgrips
Subscriber

What is the point of that?

Sounds like completely useless “green” technology.

Serious? Do you want me to explain? (not being argumentative btw – there is a real reason for it, which I can explain if you want)

YoGrant
Member

Del, incorrect. AA batteries are batteries. They are already a collection of cells. Pull one apart and its a stack of little ‘watch’ type cells.

TooTall
Member

How many AA batteries would you need to supply the OP with the correct amount of Electroconvulsive therapy ?

Half a dozen in a football sock and I can provide him with contact counselling.

cbike
Member

Alkaline AA’s are like this. I don’t think a stack of watch batteries would keep my radio mics running for 9 hours otherwise!! Some of you are watching too many spoof youtube videos.

Eyepic
Member

Put the car on the top of a gert big hill…

Get a big bloke behind the car ….. Stick single battery in cattle prod… prod the bloke into pushing the car….

Bump start car as it rolls down the hill.

It takes 1 battery. simples.

Try it if you don’t believe me. If it doesn’t work, the batteries are faulty, take them back to the shop and complain.
Remember to video and post a link on here.

molgrips
Subscriber

Del, incorrect. AA batteries are batteries. They are already a collection of cells. Pull one apart and its a stack of little ‘watch’ type cells.

Don’t think so. I have pulled them apart, and found one cell, but that was a while ago. PP3s are a stack of cells though, that’s why they are 9V.

konabunny
Member

Sounds like completely useless “green” technology.

Yeah you’re right – the designers probably put it in for no reason. Massive car companies are know for their senses of humour.

theflatboy
Member

Slight thread revival – that Anti Gravity Jump Starter, does anyone know a good price for one or an alternative in the UK, as they’re massively pricier in the UK compared to the States, and I’m also not sure if the mains charger would be UK-compatible.

I’d like to get one as a present for someone, you see.

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