Some of the online battery selectors are inaccurate - they're probably good enough to find a battery that will fit - but it may not be the correct CCA, Ah or even type as some cars with stop-start need high performane AGM batteries.

I measure the existing battery and note it's connection positions & orientation, CCA, Ah and type - then measure the battery tray and make a visual assessment whether an even bigger battery would physically fit and go from there.

With one exception all my OE batteries have lasted over 10 years and I expect replacements to do the same - I presume those who say that batteries are only good for 3-4 years buy cheap ones.

I always double check the dimensions and which way round the posts are before ordering, just makes sense, the garage might have found before that certain cars have restricted height where the battery sits and have found alternative makes a tight squeeze.

If you ever buy batteries online, there are sometimes lists of equivalent options spanning up to twenty or more battery model numbers, i have no doubt there will be some differences found in dimensions, whenever possible i get the Diesel battery if it will fit the petrol version battery tray, purely because it will be much higher spec with far higher Cold Cranking Amps than the typical petrol model.

edit, we think alike here RT.

Edited by gordonbennet on 19/09/2016 at 11:14