03 1.6 Lead or Calcium Batteries - Roly93
I think I will shortly need a new battery for my 1.6 petrol Focus. The question is do i have to replace the current battery with another Calcium battery or can I just use a regular lead acid battery, will this harm the alternator etc ?
03 1.6 Lead or Calcium Batteries - Peter.N.
I would think that any battery specified and sold as suitable for your car would be OK. Type your battery type number in on Google, there is a firm that does good quality batteries and delivers them for less that you can buy one at your local supplier. Make sure you get one of the correct AH capacity, at lot of the cheap ones are lower.
03 1.6 Lead or Calcium Batteries - elekie&a/c doctor
stick with a calcium battery .The Focus uses a smart charging/alternator system that is specifically designed to work with a calcium battery.hth
03 1.6 Lead or Calcium Batteries - foil
The calcium batteries just add some calcium to the majority lead in the plates; look at from a terminal VI characteristic I'd be surprised if you'd be able to see the difference.

So you could use either but as the addition of the calcium improves the life of the battery, it will almost certainly be better to buy the more expensive calcium type if you intend keeping the car.
03 1.6 Lead or Calcium Batteries - Screwloose

The "smart" [ECU-controlled] charging voltage of a Focus is way in excess of what a lead-acid can stand. Only a calcium battery can be fitted.

Use of an incorrect battery can cause all sorts of weird faults - even a single-cylinder misfire. Please don't ask how; because although I've seen it, I still have no idea of how it does it - but fitting a calcium battery definitely cures it.
03 1.6 Lead or Calcium Batteries - injection doc
experienced many an odd ball fault with a ford with the wrong battery fitted. Fit a calcium.
03 1.6 Lead or Calcium Batteries - MikeTorque
Yes indeed, when replacing my previous Focus battery they provided a lead acid battery and it sent the speedo awol after a few weeks and one of the battery cells blow. Got it exchanged under warantee and the same thing happened, the calcium one worked fine. The recommend battery documentation at the time wasn't correct.

For an 03 reg 1.6 the calcium battery is required.
03 1.6 Lead or Calcium Batteries - henry k
My 98 Mondeo ( same engine?) needs a calcium battery.
Charging circuitry was changed from 1997 to SCS ( Smart Charging System).
The Bosch site used to spell it out. ( no longer live)
I would be amazed if the Focus was different.

My original posting

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