A little something all of us should now be aware of is the gradual shift away from the conventional lead acid car batteries we are all used to, to the new calcium type batteries that are now prevalent in the market place. Calcium batteries are still lead acid but have calcium incorporated into the plates.
All the major new car manufacturers over recent years now specify and manufacture their cars with calcium type batteries as factory standard. As the number of vehicles with these batteries has increased, the battery suppliers have been phasing out the old lead acid type and superceding these to the new calcium type batteries. Chances are if you have bought a new battery in the last couple of years it may well be a calcium type battery.
So what does this mean for us using older cars? Not a lot really – the new batteries are more efficient with better CCA (Cold Cranking Amps) ratings, casing sizes and terminal positions have altered in some cases, so fitment may require some adjustment. The biggest thing we need to be aware of in vehicles that are infrequently used is the problems with charging the battery particularly if it has become heavily discharged (flat!). A conventional battery charger will not fully charge a calcium battery.
A 4-stage charge is used, specially designed for calcium batteries. Stage one (bulk or constant charge) quickly charges the battery while stage two, the absorption mode (constant voltage), ensures the battery is thoroughly charged. A third stage is the critical stage for calcium type batteries. It charges the battery to 16 Volts to remove any acid stratification and returns a full hydrometer reading. The final stage in the charging process (float), maintains the battery at a safe voltage ready for use.
Most garages and dealerships all now have specific calcium chargers and you can buy from auto accessory specialists calcium chargers for the home but the better ones of these are still relatively pricey.
My understanding is that a standard battery charger or permanent automatic trickle charger will maintain a calcium battery if it is not discharged. So if your battery has gone flat and it’s not that old and won’t appear to charge – you may have a calcium type battery that requires a calcium charger.