car battery

[norseman]

Judging by the replies I received to my recent query entitled 'old battery charger' it appears that there are knowledgeable people here, so may I ask a related question?
In my post I stated that I'm still wary of the existing battery, despite it only being 18 months old & I feel a renewal may be on the cards before too long.
My old 5 series BMW (2.5L) is known to be very reliant on a well charged battery, as are many cars with complex electronics, so in chosing a suitable battery should priority be given to the AH rating (handbook states 70AH) or to CCA ?

Many thanks, Merry Christmas to all forum members

 

[Burnerman]

CCA is the preferred rating, it determines how many amps the battery can deliver at a certain temperature before falling below a certain voltage.
For me, the higher capacity battery the better so long as it physically fits the tray!
18 months is no life span for a battery these days.....it could be under warranty?
Happy Christmas to you, Mr N
John

 

[norseman]

Thanks for your prompt reply John. As to whether or not the battery is still under warranty depends on how you view the legally worthless 2 years stated by the seller, as once it's past 12 months ...
I did return it after the DOK situation, but he charged it up claiming I must have a parasitic drain that ran the battery flat ... something I have yet to check though I have my doubts. Having been a loyal customer for many years I shall not darken his door again !
If I do have to replace my preference is either Yuasa or Bosch, but browsing the internet I see that batteries of the same AH rating can have different CCA ratings ie Yuasa markets 70AH units with 640CCA all the way up to 800

Norman

 

[norseman]

Update > Well I finally bought a new charger & within 8hrs. achieved a reading of 12.71V (up from 12.2V) with the meter on the connections under the hood, but strangely 12.47V from the battery terminals themselves … I thought the reading would be the other way around, given the remote locations in the engine bay.

Here's hoping for a better 2021