Depends on what car also, maybe my car has more electrical consumptions, plus a bit bigger engine to crank up. If on my wife's car, it can last more than a week or even up to 2 weeks before it goes flat.

Mark X using a Ns60 battery.
The holding charging and CCA is usually a bit low for some models.

Now Ns60 start to come with higher charging rate and CCA, can those batteries next time. Should do better

Yes, I think the battery is undersized, should've been NS70. So far my batteries can last 2+ years.
Now I'm trying the Century Ultramax rated at 434 CCA with 21 mths warranty, so we'll see how long will this last. Many recommends Amaron but a bit more expensive with shorter warranty so I try a cheaper one first.

My mf battery lasted for 3 years. Proton and kia. Actually I don't know how long it will last since I changed the battery after 3 years at the shop. Don't want nasty trouble.

New car battery usually mf since the bracket is small.

While on battery life, does the start stop feature destroy the battery or the alternator faster?

This post has been edited by mystvearn: Sep 10 2017, 10:09 PM

Start stop car needs special start stop battery type too, much more expensive than normal MF.

Ns70 is gone case nowadays.
55d23L is cheaper yet charging rate and CCA around the same.

434A? That should be a 46B24L or 50B24L

if you're daring, you can use super caps. they should last a lifetime. down side is you probably need a smaller battery to ensure there's not leakage or power lost if left not driven for a long time.

used 4nos MF batteries they all never lasted more than 2years. 1.5-1.8years max. switching back to wetcells next.

It's NS60L (46B24L if not mistaken).

True. Never able to get them last past 18months on Sonata. It seem like programmed to fail after every 18months. So consistent despite switching few brands already.

2 MF batteries on my 2002 Elantra died exactly after 1 year, just after warranty expired. So I switched to wet cells and now it's 1.5 years old, just topup the water, so far no problems.

On my City, the battery died less than a month before the car's first birthday, got replacement battery for free.