The battery inside of your vehicle will lower in its charge when it's being used for things like your radio, air conditioning or the startup of your vehicle. As long as the engine is running at some point in the near future, your battery will be recharged thanks to your alternator. As you drive faster, the battery will charge faster.
There are situations where people draw power from their battery without charging it. Once the battery is dead, you're not going to be able to rely on your alternator for a charge. You'll have to use an external battery charger from Ruxer Truck Center to get moving again. We sell these units to many of our customers in the Jasper area, and they're great to keep in your vehicle at all times. You never know when you might need to plug your battery into it to get your engine up and running again.