Weak battery, save with second

Hi there,
I overheard something recently, but I couldn't really understand or follow the speaker.

It was about a car battery that was no longer in top condition, which could be saved by connecting a second battery in parallel or series (?), and then recharging it.

Have you ever heard of or even tried this with success?
If so, is there a meaningful explanation for it?

Greetings

Hi Klaui!

This is supposedly mainly intended to help with deep discharge and sulfated batteries.
Here, a brand new battery is connected in parallel to the old one, using cables with the maximum possible thickness, and then the two batteries are charged together.

The goal is that when the sulfate crystals are broken or when the battery is recharged, only a small amount of charging current is actually taken, but there are short and high current peaks that are not measurable by us (in a temporal) manner. A charger can handle these current peaks (in the µs range)? I don't know...) however, if not delivered, a portion of the sulfate layer cannot be recovered, which might have worked if...
Hoping I could explain it roughly, what it should achieve

As I said, all theory and practice: nonsense, doesn't work! Discharged and sulfated batteries can never be obtained as new.
Furthermore, this approach is EXTREMELY counterproductive when intelligent charging technology is used.

Best regards from Munich!

Understood, thank you

A small example where I could try it out,
I have a battery in my summer vehicle, which has been deeply discharged several times to avoid complete failure, and I would like to revive it with a second battery, but this battery fails under high starting currents.

A new one, of course, won't come out, but it might still be okay enough to accompany me for 2-3 more years if I regularly reload it.

Would it be appropriate here, or according to your statement, also "Schmarn"?
It's also possible that the urge to tinker and experiment is something that appeals to me here, but if it doesn't work out, I'll save on electricity.

Hi Klaui!

I have already answered that question above.
But let your imagination run wild and tell me what you came up with

Best regards from Munich!

Things to consider if you believe in them: There are pulsators that can be permanently installed in the vehicle and are supposed to prevent or at least slow down sulfation. However, they draw power directly from the vehicle's battery, thus accelerating the discharge. This, in turn, provides fuel for the sulfation process. If the self-discharge can be compensated for, then such a battery would be a consideration for vehicles that are not driven regularly.

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As I said, all of this is just theory, and to that I would add: nonsense, it doesn't do anything! Deeply discharged and sulfated batteries can never be restored to their original condition.

. Such actions are a waste of time with deeply discharged batteries older than 3 years - they fail in 90% of cases and are simply a waste of time. Experience has shown that the battery will eventually need to be replaced. Why not right away?

Had only half-grasped it, as mentioned before.
Then I'd probably rather save the money and buy a new one at the beginning of the session.

Hello everyone!

@Klaui: Ich würde sogar OpaAutoschrauBär's Quote von 90 auf 97% erhöhen. Und selbst wenn Sie mit Ihrem alten Akku unter den "glücklichen" 3% liegen, dann werden Sie feststellen, dass dieser Sie im ungünstigsten Moment plötzlich im Stich lässt; vorzugsweise um 3 Uhr morgens in der Wüste, ohne Funkkontakt. Phone is dead

As you know, I also enjoy playing and want to know. Therefore, I can easily understand that it interests you. So, just do it. Don't expect anything from it.

Best regards from Munich!

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Then I'd probably rather save the time and buy a new one at the beginning of the session. icon_wink.gif

Exactly - and we'll avoid further pointless discussions and close this here