Is this battery suitable for the Mk2 1.6 Petrol?

https://www.gsfcarparts.com/products/ybx5000-silver-high-performance-smf-batteries-5-year-warranty-za042676

If not, what is the recommended choice?

I have read on here that all Fords built after 1997 have smart charging systems and require suitable batteries.

I have tried two different electronic battery testing devices on the fitted battery. Both say that the battery now on the car is only around 33% capacity. The car still starts fine, even in cold weather. I am planning to replace the battery before it actually fails.

Thanks for any info.

Yes, Yuasa is a good battery and will be suitable for your car. 

I just fitted a 7000 series YUASA to my Focus 2016, and things that never worked Start/Stop etc are working now. Not sure if your car has the more modern type of BMS but if it does remember to to the reset after you fully charge the battery, preferably before you fit it.

This is the very battery I had fitted to my car last year - no issues...

Technically not suitable for SmartCharge as it should be Silver Calcium.  But you won't find one of those cheaply or easily nowadays.  It will do the job, just have to accept a shorter battery life than the original.

Thanks for the replies.

The manufacturer data sheet at the link below says "Ca/Ca" in the technology section. From that I assumed it was a calcium battery.

https://www.yuasa.co.uk/batteries/automotive/ybx5000-silver-high-performance-smf-batteries/ybx5075.html

48 minutes ago, AntonovAN12 said:

says "Ca/Ca" in the technology section. From that I assumed it was a calcium battery.

It is 👍

The original was a Ag/Ca, Silver Calcium

Never seen any of those new for about 10 years now.

Thanks for the replies.

Yuasa claim that their calcium batteries are a suitable replacement for the Ford Silver Calcium types.

Has this been found to be incorrect?

https://www.yuasa.co.uk/info/technical/silver-calcium-batteries/

Also, what is the reason that the Mk1 1.6 is fitted with a smaller capacity battery? Does the Mk2 have a more powerful starter motor?

51 minutes ago, AntonovAN12 said:

Has this been found to be incorrect?

Yes, it is partly incorrect.

It is the 'best match' available to replace the Silver Calcium, but is in no way perfect. The original Ag/Ca batteries typically lasted 10 years and during that time performed almost as good as new until finally dying in a few short weeks.

The new Ca/Ca batteries will at best last only 5 years. Over time they degrade and there capacity is constantly reduced, until they have to be replaced. Given the option the original Ag/Ca battery is better, but as has already been said they are no longer available.

The Great Thunberg's of this world decided to outlaw Silver Calcium batteries in favour of the Calcium Calcium batteries so that cars could use at least twice as many of them and save the planet 🤣

10 hours ago, unofix said:

The Great Thunberg's of this world decided to outlaw Silver Calcium batteries in favour of the Calcium Calcium batteries so that cars could use at least twice as many of them and save the planet 🤣

Maybe she should be in government, she's certainly competent enough 😂

On 2/19/2025 at 6:48 PM, StephenFord said:

This is the very battery I had fitted to my car last year - no issues...

I have same one. Seems to do just fine. Works better than whatever rust bucket was in the car when I bought it

Thanks for the replies.

I bought and fitted the battery yesterday.

There is a noticeable improvement to the starting.