Why doesn't my pickup truck start?

We don't know where you're reading this from or what your circumstances are, but if your pickup truck won't start, it's difficult for us to offer a definitive reason for the situation you are in right now. We don't even know if your truck has a diesel or gas engine. What we can do is offer some insight into whether or not the battery might be the issue. 

If the engine is cranking, but not turning over, that means the battery is supplying power, but there could be an issue somewhere else, possibly in the fuel system or ignition system. While these situations rarely occur in an ideal location or at an ideal time, if you have access to a volt meter, you could measure the voltage of your battery. It's best to take this measurement directly at the battery terminals and fully-charged, your battery should measure at least 12.6 volts. 

If the engine of your truck isn't making any noise when you turn the key or you hear a clicking sound and/or your dashboard lights dim, flicker or don't come on, then you could have an issue with your battery. If you drove the truck recently, it's likely not related to the connections at the battery terminals. If you haven't driven the truck in a while, it would be worth checking to see if the battery cables are connected securely to the battery terminals.

Should I Use Jumper Cables or a Jump Box?

Jumper cables or a jump box may be able to get your truck started and they are great tools to use in emergency situations. However, they are not the ultimate solution to your issue. If you need to use jumper cables or a jump box to get your truck started, you should fully-recharge your battery to at least 12.6 with a battery charger as soon as possible. Alternators are not designed to recharge deeply-discharged batteries. Many alternators will say that specifically on the box they come in.

Alternators are designed (and often warrantied) to maintain proper voltage in batteries that are near a full state of charge, not recover deeply-discharged batteries. Asking that task from your alternator can lead to a cycle of dead batteries and jump-starts, until either the battery or alternator fails.

Think of jumper cables or jump boxes as the electrical equivalent of a one-gallon can of gas. If your truck was out of gas and you put one gallon in it, you'd probably be looking for a gas station very soon. Think of a set of jumper cables or a jump box in the same light and start looking for a battery charger as soon as possible (and don't shut off your truck until you do).

Once you get your battery fully-charged, it might be a good idea to have it load-tested by a battery professional. Many quality auto parts stores will offer this service free of charge and it can give you a good indication of whether your battery needs to be replaced or not.