Said It Here

Why did my car battery die again right after a jump start?

Thin jumper cables lack the thickness needed to push enough current through a severely drained battery, and shutting the engine off immediately prevents the alternator from recharging it. Without letting the car run or using a heavy-duty cable, the battery will not hold enough power to start the engine again.

What people tried

Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.

  1. 1
    Using thicker, higher-quality jumper cables
  2. 2
    Leaving the donor car connected to charge the dead battery for a longer period
  3. 3
    Recharging the dead battery overnight
  4. 4
    Jump-starting the vehicle after it dies
  5. 5
    Checking battery and alternator voltage with a multimeter

In their words

Unedited, most upvoted first, each linked to the thread it came from.

my car battery died like 20 min ago, I got it jumped start but this is my first car so I didn’t know I was supposed to let it run/ charge, so I got home like 5 min after and turned it off.source ↗

Top_Willingness_8792 · r/AskMechanics · 3 upvotes

I have the most ridiculously beefy pair of cables I’ve ever seen in my life. Didn’t have them with me today and used the skinniest cheapest pair I’ve ever seen to attempt the jump.source ↗

RiverWalker83 · r/MechanicAdvice · 1 upvotes

Where this came up

People with this problem also raised