How can reversing current affect battery charging?

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Discussion Overview

The discussion centers on the effects of reversing current direction on battery charging, exploring theoretical and practical implications. Participants consider different battery types, charging mechanisms, and the role of components like diodes in preventing reverse current issues.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions whether reversing current direction can charge a battery, referencing the generation of emf when moving a magnet through a coil.
  • Another participant asserts that reversing current direction using an external power source will charge the battery, emphasizing that this is the only direction that does so.
  • A different viewpoint suggests that the ability to charge in reverse depends on the battery type, noting that some batteries, like capacitors, can be charged in either direction, while chemical batteries may not.
  • One participant describes a practical example involving a shake-up flashlight, indicating that reversing current can drain the battery and speculating about the presence of diodes to prevent this issue.
  • Another participant mentions the use of diode rectifiers to couple AC from a coil into a battery, highlighting their role in preventing the charging circuit from becoming a load on the battery.
  • A participant warns about the dangers of connecting a battery charger incorrectly, which could lead to harmful chemical reactions in the battery, despite the presence of diodes.
  • Concerns are raised about avoiding reverse current charging, with emphasis on the design of dedicated battery chargers that prevent incorrect connections.

Areas of Agreement / Disagreement

Participants express differing views on whether reversing current can charge a battery, with some asserting it is possible under certain conditions while others caution against it depending on battery type and connection methods. The discussion remains unresolved regarding the implications of reversing current on battery health.

Contextual Notes

Participants acknowledge that the effects of reversing current may vary based on battery chemistry and design, and there are concerns about potential damage to batteries when connected incorrectly. The role of diodes in preventing reverse current is also noted but not fully resolved.

spidey
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i am connecting a wire to a battery and i pass current in wire and so battery will be charged.suppose if i change the direction of current then will the battery charge? i.e if i change the direction of current alternatively after some time?

why i am confused is because of this? suppose if i move magnet through a coil connected to battery then an emf will be generated and is stored in battery.then if i move the magnet away i.e in opposite direction then the direction of current is reversed so now will the battery charge?
 
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When you hook up a circuit to a battery to power a light for instance, current will flow until the battery is drained. Reversing the direction of the current through the battery using an external power source will charge the battery. This direction is the ONLY direction that charges the battery.
 
I would say it depends on the battery type. A capacitor, electrolytic for example, can be charged in either direction. A car battery or chemical battery structure may be different.

This is a good question, if you think about one of those cheap, shake up flash lights - they have a coil and then a metal slug in them, so the slug goes through the coil and this produces energy that gets stored in the battery. If it goes the other way though, you just drained that battery. My guess is that they have a diode built into them and that you only get power in one direction.
 
Guys, you use a diode rectifier to couple the AC from a coil into a battery to form the charging circuit. The diode also keeps the charging circuit from being a load to the battery.
 
how can we aviod reverse current charging
 
You have to be careful to avoid this.

If you connected a battery charger the wrong way around to a car battery that was already flat, you could attempt to charge the battery the wrong way around and it would possibly harm the battery by causing unwanted chemical reactions in the battery.

Although the battery charger contains diodes, they would be conducting normally in this case, but still doing damage to the battery.

This is why dedicated battery chargers, like those used on laptop computers for example, always have a plug that can only be connected the right way around.
 

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