WHAT SIZE MAKES SENSE?

Balance: A lot out a lot in

Modern vehicles already have elaborate safety and comfort systems installed ex works. And as a user, you want to supply more and more consumers, whether it's the high-end hi-fi system in the car or the refrigerator in the camper. A larger battery with more capacity and power sounds good, but can the alternator handle it? It is supposed to charge the starter battery under normal circumstances. Where a lot is supposed to come out, a lot has to come in.

Room for more?

The installation method also sets limits as to whether anything larger can be installed at all. In other words, is there room for a larger battery box than the one we have right now. If there is still some play, it is worth measuring to check whether the next larger battery will fit in.

You can see how to measure correctly when every millimeter counts in the video "How to determine the dimensions of a battery correctly?"

No margin on the voltage

The voltage is always specified by the manufacturers. If you have a 12-volt car, you can only install a 12-volt battery.

Crucial for starter batteries: the cold start performance

Even batteries with the same voltage, almost the same ampere-hour numbers and the same dimensions can have significant differences in cold start value. The power, the current that it can deliver under load, is significantly higher in an intAct Premium Power, for example, than in a similarly sized intAct Race Power. This is due to the design of the battery. The larger power reserve becomes interesting when it comes to starting in cold conditions.

Capacity, not only important for supply batteries

The ampere-hours are basically interesting for starter batteries in the newer vehicles, which have a lot of convenience electronics in them. Sufficient capacity ensures that it can also supply these consumers. Of course, this is even more interesting if I use the battery as a supply battery. In the leisure area, on a boat, perhaps also in the garden shed. Here it makes sense to calculate the capacity.

Calculate capacity

A rough calculation is relatively simple.

• Add up the wattage values of the consumers, coffee machine, PC, refrigerator, for example.
• Read the required voltage, 12 or 24 volts, on the type plates. 
  Watts divided by volts gives the ampere number.
• The hours result from how long you want to operate these consumers in the maximum case, so ampere number times the desired hours gives the Ah value.
• To this you add a safety reserve, because you can't discharge the battery to 100%, so you add 30% to the Ah-value.

And that roughly gives the capacity value that your battery should provide.

If a larger battery fits in your vehicle - go for it. This automatically gives you more cold-starting power. As long as your alternator can do the same. With traction and supply batteries, the only thing that helps is calculating so that the refrigerator and coffee machine don't go out.