There are a couple of reasons a battery is dead. 1 leaving the lights on. 2 when it is extreme hot or cold due to the wether. 3 yourbattery is to old and is really dead/broken. Replace with a new one.

With this guide, you can start your car with a dead battery easy and quickly. You can also help other persons the easy way.

Do not get a cheap and small battery booster. The cheap ones can not boost a big van or truck. I have mine always with me in my car.

This for example, this is a good booster.

Be sure to charge the booster fully once a month or 2 months. Because it is always 100% and your booster lasts longer this way.

Connect first the red cable + from booster to red + from battery. Second connect the black cable - to black - from battery. Do not connect incorrect. It damages a lot. Battery and electra from car.