Gone are the days when a battery was just a battery.
Hopefully this will help you out.
A majority of batteries available in NZ now have Calcium in them which generally won't give you too much trouble unless you start to cycle it (drain/recharge/drain etc). These batteries are generally used to start a vehicle and that's it. Battery size/CCA is based on what is required by the vehicle when it came off the factory floor so if you add to it you'll start to overload the battery. The best way to describe a battery is to compare it to a car. You have CCA (Cold Cranking Amps) and Voltage. CCA is what is used to crank over your engine, the Volts is there to supply power so you can utilise the CCA. CCA can be compared to fuel, and the voltage can be compared to the oil in an engine. You need both to start the vehicle. If you have a new battery that is just flat, bit like having a full tank, but no oil in your engine. If your battery is fully charged but is old it's like the fuel tank is empty. Doesn't matter what oil you've got, with no fuel it won't start, likewise, engine has oil but no fuel, still won't start
Battery size (CCA wise) is important too, a Bambina will go a fair distance with a tank of fuel however, if you put a V8 in that Bambina and DON'T change the size of the fuel tank..well, that fuel isn't going to last long..same with a battery. The higher the compression, the larger the CCA needed. What will start a 5ltr petrol V8 Commodore/Falcon (approx 530CCA) won't stand a chance in a 3ltr diesel.
If you're wanting to use the battery for other than just starting your vehicle would suggest asking for an antimony battery. Be aware that the high output alternators WILL make it gas so you DO need to keep an eye on the water levels regularly. Antimony battery will have a slightly lower CCA however this is due to the number of plates per cell. The more and thinner plates per cell = more surface area in contact with the acid = higher CCA HOWEVER you do lose Reserve Capacity (RC). The less and thicker plates per cell = Higher RC HOWEVER you do drop in CCA.
Personally myself have a D34/78 Yellow top Optima in my GQ and two in my MK for two reasons, 1st extremely high CCA AND has a decent RC so can handle a decent load and secondly due to them being coils of lead and not plates, can handle vibration extremely well. Apart from that if you roll the vehicle, as they're sealed and have a paste like substance and not acid flooded..no acid spill.
Flat batteries can now be a bit of a pain due to the Calcium content. There are two ways they can go flat. 1st is the most common and it's the drain. This is where something in the vehicle has drained the battery (no one admits to leaving the lights on
) and is the worse kind for Calcium batteries. Gunk/Mud on the top of your battery can also do this. If you put a multimeter lead on a terminal and the other somewhere on your battery between the other post and you get a reading you're getting a flat battery with it just sitting there as you can lose around 10volts that way. A clean-down will fix that. A standard charger..or even your alternator, will not be able to bring it back to life. All they do is pump it up with amps until it's close to fully charged and then floats the charge. You're basically only giving it a surface charge (topping up the oil). You'll need it put on a calcium charger as they are quite different in make up, they charge up the battery like the standard charger/alternator but instead of going to a float, take a big jump in increasing the amps again before going back to a float..this bit is what can bring it back to life. Don't go and buy one, just take it into someone that has a calcium charger (auto sparkies/battery suppliers) and they'll generally do it for either free or bugger all. The other way a battery can go flat is surface discharge, normal charging can fix this but take a long time for a discharge this way to affect anything, it's about .01% of the voltage per day.
DEAD FLAT batteries don't mean it's DEAD.
If your battery drops below 4-5ish volts (dependent on charger type) you'll never charge it. The charger will look at it as it NOT being a battery and won't put a charge into it. A current needs to be forced into it prior to putting it on a charger as it gives it a surface charge that a charger will pick up on and start charging it..DON'T DO THIS yourself. Go to an auto sparkie/battery supplier as they KNOW what they're doing. Batteries give off Hydrogen gas as they're being charged and if you try it yourself there is the chance you may cause a spark...spark + hydrogen = well, not pretty
Please note, all the above is just to help others understand the basics of batteries. I've tried to make it as non-technical and simple as possible
