Charge an emergency fan on AC or DC setting?

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Discussion Overview

The discussion revolves around the appropriate setting (AC or DC) for charging an emergency fan that has both options. Participants explore the implications of the AC/DC switch on the charging process and the fan's operation during power failures.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant notes that the fan can be charged on either AC or DC settings, as indicated by their experience.
  • Another participant suggests that the AC/DC switch likely selects the power source for the fan motor, implying it does not affect the charging process.
  • A different viewpoint raises the possibility that the switch is positioned after the battery, thus having no impact on the charging circuit.
  • One participant cautions that the charger's current capacity should be considered, suggesting that it could be a trickle charger and recommending charging on the AC setting.
  • Another participant proposes an experimental approach, suggesting to run the fan until the battery is depleted and then test charging in the DC position.
  • A participant shares their experiment results, stating that the fan charges fully in the DC position and concludes that the AC/DC button does not affect the battery.
  • One participant expresses interest in examining the internal wiring of the fan for clarity on the AC/DC function.

Areas of Agreement / Disagreement

Participants express differing views on the implications of the AC/DC switch regarding charging. While some agree that it does not affect the charging process, others raise concerns about the charger’s capacity and the potential for different charging behaviors based on the setting used.

Contextual Notes

There is uncertainty regarding the charger's specifications and the internal wiring of the fan, which may influence the charging process. Participants have not reached a consensus on the best charging practice.

Who May Find This Useful

This discussion may be useful for individuals seeking to understand the operation and charging mechanisms of emergency fans with AC/DC functionality, particularly in contexts of power failure preparedness.

t3rom
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I've an emergency fan with an AC/DC button on it, but its manual doesn't say on which setting it should be charged. I've tried charging on both settings, and it can be charged either way.

On the back of the fan it reads:

"AC 220/240
50/60Hz
19w"

The fan's box only says:

"DC: Operate when power failure.
AC: Operate by AC power directly"

My question is on which setting (AC/DC) I should charge it for future use when there's a power failure? Thanks in advance!

This is not a homework question.
 
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The AC / DC switch probably selects the source of power for the fan motor.
So it does not matter which is selected during charging of the internal battery.
 
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I see. Thanks for the reply!
 
Also -the switch is most likely "after" the battery, so it has no effect on the charging circuit.
 
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I agree With Mr. Baluncore. The Switch itself selects the Power source(whether AC/DC). No matter on Battery charging.
 
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That's assuming the charger's current capacity is more than the fan draws.
It could be a trickle charger.

Knowing no more than has been posted, I'd charge it on AC setting.

But one experiment is worth a thousand expert opinions...
Try it overnight - run battery down and then see whether it'll charge back up with fan running in DC position ??
 
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I would just take it apart and have a look. The wiring should be straight forward.
 
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jim hardy said:
But one experiment is worth a thousand expert opinions...
Try it overnight - run battery down and then see whether it'll charge back up with fan running in DC position ??

Well, I did that and it does charge fully on DC position. I'm also drawing this conclusion that the AC/DC button has nothing to do with the battery.
 
Last edited:
dlgoff said:
I would just take it apart and have a look. The wiring should be straight forward.

That's actually not a bad idea. I'll do that even though I understand the AC/DC option has no effect on the battery.
 

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