A lot can be said by the cranking behaviour. If the cranking itself is slow, look at the battery before anything else. However if the cranking is lively as usual but still it does not start, that's mostly not the battery's fault though you can confirm it once more by honking your horn and checking if it's powerful(thinking about some idiot you encountered on the read helps
). The problem might be anything from injectors to compression losses. Batteries usually last for four to five years, and can squeeze even another year with utmost care. And BTW, hope you don't crank it continuously (risky to starter motor and battery)