Long story short, 2 years ago, my wife brought her car in for normal servicing to the dealership. They told her the battery needed to be replaced. She said she didn't want them to replace the battery.

After this for some reason, all visits to the dealership, the battery tested "Good". I asked 2 people and they said what might have happened was the dealership could have charged the battery so that it tests "Good" again.

Logically, this doesn't make sense because it would behoove them to sell you a new battery at marked up prices than to charge your battery for you so that it's good. Also, if it tested bad, it should have died by now, which it hasn't. Only because I was going thru the old records, did I come across this and now I'm changing the battery proactively before it really dies.

So my questions are:

  1. Does a dealership have this magical charging device to make a battery be "Good" from "Replace"
  2. If they do have this device, why would they do this, than sell you a marked up battery?
  3. Also, if they have this magical device, would a battery go from "replace" to "good" and stay good for 2 years?
  • You are assuming that the battery they tested as "needs replacing" was the one fitted to the car and you're assuming their sales and workshop managers weren't in cahoots to sell batteries. I personally wouldn't change a battery that has been tested as "Good". I'd have it independently tested and watch it being tested. Commented Oct 14, 2019 at 10:14

2 Answers 2


Answers to your 3 questions:

1) No, there is no such "magical" device. If there were, everyone else would know about it too. When a battery is past the end of its service life there is no process to revive it.

2) Moot question in light of the first question.

3) I'm going to speculate that the initial test was faulty. The dealer likely charged the battery and after that it was "good".

I suspect the initial diagnosis was based on the age of the battery and not a diagnostic test. It's not uncommon for a dealer to note that a battery is older than some arbitrary age and recommend a replacement to save the owner of the car the trouble of a breakdown at some inconvenient time.

  • 1
    I have tested a battery as "good" one day, then faulty the next...
    – Solar Mike
    Commented Oct 14, 2019 at 11:22

No magical devices to bring a battery back to life.... except water if the level in low.

Based on my experiences with dealers, a crooked service tech told her a good battery needed to be replaced. During the visits later on, you got an honest tech.

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