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There are bracelets for protection from static electricity, but you have to touch it to ground to discharge. Can we use a battery (like watch batteries) on this bracelet?

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  • \$\begingroup\$ What function do you think the battery would perform? \$\endgroup\$ Commented Feb 17, 2023 at 5:39
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    \$\begingroup\$ I’m concerned about these bracelets. The only static protection bracelets I’m aware of require a ground connection at all times. Do you have a reference to the bracelets you’re talking about? \$\endgroup\$
    – Bryan
    Commented Feb 17, 2023 at 5:42
  • \$\begingroup\$ What bracelet is this about? \$\endgroup\$
    – StarCat
    Commented Feb 17, 2023 at 7:48
  • \$\begingroup\$ @StarCat search for “grounding bracelet” on Amazon. \$\endgroup\$
    – WhoCares
    Commented Feb 17, 2023 at 7:56
  • \$\begingroup\$ A "bracelet" to me is something that is worn and has no wired connection to anything. A "wrist strap" or "grounding strap" does have a connection to ground, usually through a high value resistor, for the purpose of controlling static but without endangering the wearer. The term "bracelet" probably got introduced through a language translation misunderstanding. \$\endgroup\$
    – JYelton
    Commented Feb 17, 2023 at 18:09

3 Answers 3

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A battery might technically be used to dump some of the static charge into, but only as much as into a simple similarly sized chunk of metal, or indeed the bracelet itself. That is, the mechanism that makes a battery a battery is not involved, as that works by charges moving from one terminal to another, without affecting the static charge of the entire thing.

In any case, none of it will completely discharge you i.e. bring your body to earth voltage, it can only "dillute" the static charge by spreading it out. If the bracelet/battery even are at a lower potential than your body to begin with, that is. And comparing the size of a big blob of meat and water to that of a bracelet or battery, the effect of these things is rather minimal at all. Basically, lacking further details, those bracelets are a scam if advertised the way you describe (assuming that "touching them to ground to discharge" means doing so intermittently instead of having it constantly connected).

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If neither of the battery's terminals are "earthed", then all you are doing when your statically-charged-ten-thousand-volt-different-from-earth-potential finger touches the battery is raise/lower the battery's potential to also be 10000V different from earth. Inductance and capacitance notwithstanding, no charge will leave your body and end up in the battery somehow.

The battery will be capacitively and inductively coupled to earth also, but ignoring those two aspects, the principle is sound: How can charge flow onto something completely isolated from everything else? Kirchhoff's Current Law tells you that if charge flows into the battery, the same amount of charge must flow out somewhere else. If the battery is "floating", there's nowhere for charge to leave, and therefore no way for charge on your body to enter it in the first place.

The battery will simply have 10000V potential (relative to earth) now too.

Whatever thing you touch to discharge your body must provide a route to earth, for charge to leave your body via that thing, meaning that the only way for the battery to be such a route is if one of its terminals is connected to earth too.

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  • \$\begingroup\$ How about using an empty rechargable battery? \$\endgroup\$
    – WhoCares
    Commented Feb 17, 2023 at 7:40
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The electricity charges on your body have the potential to reference the Earth. This is because you are in touch with the earth.

To discharge the electricity in your body, you need to connect your body to an object with the same potential as the Earth. We don't know how much potential a battery has relative to the ground, unless you connect it to the ground.

Generally, we need storage that can store charges from another place with the same reference potential, just like two conductive spheres are isolated from the Earth but they have different potentials to the same Earth.

About the battery you cited, you need to ensure that the battery has a reference same as the electrostatic source. Only in this situation can you use the battery. You need to ensure the reference is alive during and/or after discharging.

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    \$\begingroup\$ What do you mean by "You need to ensure the reference is alive during and/or after discharging"? A ground reference, by definition, is not powered. \$\endgroup\$
    – PMF
    Commented Feb 17, 2023 at 6:26
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    \$\begingroup\$ A battery does nothing for discharging electrostatic charge. You can still get zapped when you touch a car - and it certainly has a battery. You would have to ground the battery - at which point you don't need the battery. \$\endgroup\$
    – JRE
    Commented Feb 17, 2023 at 6:27

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