if the battery is nearly dead you are going to have to get it charged. The one downside of alternators is they have to have voltage to make voltage. If the battery drops too low they dont put out, and the vehicle wont run. If your asking will it crank with a jump, again it depends on how dead it is. If the connections are corrodedit just makes it worse. There are lots of unanswered questions in your request. YMM is always needed, Year, Make and Model. How old is the battery? Have you checked that the battery connections are clean and tight? What is a long trip? To some that might mean 50 miles, to others a couple thousand.
And if you do get it started DO NOT remove the battery cables while it is running to see if its charging. Unless you like buying ECMS. That method went out
30 years ago. Do it to an early ford, no ecm but electronic ignition and you will buy a new ignition module.While on this subject, the proper way to jump start. Vehicle providing the boost is shut off before the cables are connected. Regardless of wither the vehicle being jumped starts or not the vehicle providing the boost is shut off before the cables are disconnected. The reason for this method is to avoid damaging the computer systems on the vehicle providing the boost. If the vehicle being jumped has a severly discharged battery it will pull a ton of amps and cause a hefty voltage drop. When the cables are removed, the amp load goes away, you get a massive voltage spike. Computers do not like huge voltage fluctuations.
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