Is there any point overspeccing a car battery?

[swiftpete]

My battery has karked it, I'm going to buy another, but wondered if there is any point buying a battery with more cca and ah over what's already in it? I have been told to get the most I can, but is there any point? I don't want to start throwing away cash if it's not worth it, but I don't really want to get stranded ever again ideally.

Cheers

[Iain328]

swiftpete said:

My battery has karked it, I'm going to buy another, but wondered if there is any point buying a battery with more cca and ah over what's already in it? I have been told to get the most I can, but is there any point? I don't want to start throwing away cash if it's not worth it, but I don't really want to get stranded ever again ideally.

Cheers

CCA is a measure of the capacity of the battery, the AH rating is the measure of strength of it. You can have a battery with a high AH rating but relatively low CCA rating so it 'll pack a punch, but not for as long as a battery with a higher CCA rating

More of both is better IMO.

[king arthur]

There possibly is at this time of year, especially if you don't use your car every day to keep it charged, or make lots of short trips. I would say what is more important though is to buy a decent make of battery.

[shirt]

i would choose a heavier duty battery for sure. i once paid through the nose for a serious bosch one for a renault diesel when i broke down miles away from home. its been in every petrol car i've had since.

[LeoSayer]

I wouldn't go for any spec other than manufacturer's recommendation.

[2 Wycked]

I had a big bugger off van battery in my last E36 just because it's what I had lying around. I don't know that there are any benefits to it but nothing bad happened.

[Charlie Foxtrot]

2 Wycked said:

I had a big bugger off van battery in my last E36 just because it's what I had lying around. I don't know that there are any benefits to it but nothing bad happened.

Did similar in my old AX, put a massive battery off a boat (mercruiser V8) only had to breath on the key and it would start.

[grumbledoak]

Iain328 said:

CCA is a measure of the capacity of the battery, the AH rating is the measure of strength of it. You can have a battery with a high AH rating but relatively low CCA rating so it 'll pack a punch, but not for as long as a battery with a higher CCA rating

More of both is better IMO.

I think you have that the wrong way round, but more of both is better.

[aka_kerrly]

grumbledoak said:

Iain328 said:

CCA is a measure of the capacity of the battery, the AH rating is the measure of strength of it. You can have a battery with a high AH rating but relatively low CCA rating so it 'll pack a punch, but not for as long as a battery with a higher CCA rating

More of both is better IMO.

I think you have that the wrong way round, but more of both is better.

my understanding is cold cranking amps (CCA) is a measure of how effective the battery is at 0 degrees. It measures how long the battery can be used at full voltage before the voltage drops below 7V (iirc) so a higher CCA figure is great in the winter because it means that in cold weather when you are likely to have to crank the engine over a little longer the battery will remain powerful.

The amp hours is a measure of how long the battery can last before it is discharged. So a higher amp hour figure means that for example if you left your lights on the battery will survive longer before dropping below 10v (which i think* is when a 12v battery is determined to need charging)

dave

[grumbledoak]

Thanks Dave, more precise than I could manage without google.

I was just looking at the units: CCA would more be 'strength' and AH 'capacity'.

[pacman1]

LeoSayer said:

I wouldn't go for any spec other than manufacturer's recommendation.

I'd be inclined to go with this, but perhaps a heavier duty version that is recommended by the manufacturer.
When I researched this a while back, it seems that in order for a battery to work correctly and most importantly last a long time, it's ability to charge via the correct alternator and discharge via normal use is critical. Battery chargers have a trickle facility, and are often referred to as conditioners. There are all sorts of ailments batteries can suffer from if the vehicle is not used as the car manufacturer or battery manufacturer intended. You won't know about them until the battery suffers an early failure.

If you really want to significantly alter tha type of battery on your car, other than a heavy duty version designed for that model, I'd be inclined to seek the advice of an auto electrician who may suggest you fit a different alternator to suit.

The most cost effective and hassle free route to take IMHO whould be to invest in the correct battery, but buy the best quality one with the longest of guarantees.

Edited by pacman1 on Thursday 2nd December 17:08

[lescombes]

get a lot of this on Bongo Fury (Mazda Bongo owners club)....factory fit is 60Ah and winter spec is 64Ah ....Japanese batteries specs..... closest in the UK is the 068 70Ah battery or the 249 95Ah battery....
Some choose the lower ah some the higher.... BUT they both have the same warranties.... Yer pays yer money IMHO... I went for the 068 for my diesel...closest to factory spec plus 660 CCA.. 3 years warranty, £41 and starts on the button

[Yazza54]

LeoSayer said:

I wouldn't go for any spec other than manufacturer's recommendation.

In case you put one on that's too good...?

[MJK 24]

My Scirocco 1.6 diesel has a battery taken directly from a Merc 2.5 diesel.

Starts immediately - even when it was -7 Monday morning. The only downside I can see is that it weighs a little more.

My car is often left unused Monday - Friday. At this time of year, after it been stood frozen solid for 5 days and nights, I want it to start without fuss or complaint. I'm yet to be disappointed.

[pacman1]

Yazza54 said:

LeoSayer said:

I wouldn't go for any spec other than manufacturer's recommendation.

In case you put one on that's too good...?

If you mean a top end battery that is suitable for the car, then yes.

If you mean any old massive battery, then no.

[Yazza54]

pacman1 said:

Yazza54 said:

LeoSayer said:

I wouldn't go for any spec other than manufacturer's recommendation.

In case you put one on that's too good...?

If you mean a top end battery that is suitable for the car, then yes.

If you mean any old massive battery, then no.

I'd just go for the highest cca & ah you can get within the same battery size so it's a direct replacement and upgrade in one.

[Jgtv]

Used to have a battery for a diesel transit in my old Alfa, simply because it was the only one that fitted, even a battery from Alfa with the exact part number was a completely diffrent size & shape, awkward bugger it was to fit and Jump start too.


Nothing bad battery related happed either.

[Pesty]

Could there be implicatons for you alternator if you go too far with a heavy duty battery?

doesn't the resistance of the batery increase for instance so a wimpy alternator may struggle?

[carsounds_dan]

I'm an auto electrician by trade and the general feeling within the trade is that as long as your charging system is up to scratch with you old battery it'll look after your new one fine.

If your having issues with your charging system get it checked rather than stick a massive battery in it.
My van runs the standard weedy looking battery from standard, but has a second battery stored behind the passenger seat which runs through a dedicated split charging system. This can, if necessary be connected strait to the other battery to "jump start" the vehicle should I run the standard battery flat.

Saying that, my battery is getting to the end of it's life, and I still do not have any notable issues with starting etc given the cold weather.

So in short... if your cars charging circuit is up the old batterys then it'll certainly look after the new one, so get it checked by your local auto electrician and go spend some money!

[XG332]

Battery on the 4x4 gave up last week. Bought a new one from halfords but it was wrong for £75. £20 scrap yard done.