# Can a 9 V battery kill you?

Suppose I connect a 9 V DC battery to a DC-to-AC converter. Then connect the output of the converter to a step-up transformer, which increases the voltage to 2000 V. Now, if I put myself between the ends of the terminals of the secondary circuit of the transformer (i.e. I'm the load), will I be electrocuted? (Assuming my body resistance to be 1000 Ohms.)

I think 2000 V and 1000 Ohms can produce about 2 A of current through my body, which could be fatal. This means I'm drawing about 4000 J of energy per second from the battery. A quick google search tells me that a standard 9 V battery may contain 20,000 J of energy. If that's true, 2 A current will go through my body for about 5 seconds before the battery is completely drained. I'll be fried like a potato for sure if that happens.

Are my reasoning and numbers fairly correct? Can a 9 V battery kill you?

Also, what would happen if the 9 V DC is coming from an adapter connected to a 230 V AC power source and not from a DC battery? If I'm the load, would 2 A current flow non-stop through my body in such a scenario (until the AC power source is depleted)?

• A standard 9 V battery is comprised of 6 series AAAA batteries, more or less: you can carefully take a dead one apart with pliers and see for yourself. These cells are smaller than AAA cells, so this post might help: electronics.stackexchange.com/a/591473/223146. In college, I once built a tickler circuit that stepped up the output of a 9 V battery to around 1200 V. I was going to use it for a prank, but got zapped right after I finished construction. Decided to skip the prank. No real harm, but not funny in any event. Ps. I did not down vote.
– Ed V
Commented Jan 3, 2022 at 20:07
• I do not know what batteries or circuitry is used in stun guns, but maybe someone here can comment on that, if relevant.
– Ed V
Commented Jan 3, 2022 at 20:24
• The 9 volt battery probably can't deliver enough power to kill you, but if you charged a capacitor and used that, you would be in real danger. Commented Jan 3, 2022 at 20:28
• Even dead shorted, you cannot get 2 amps from a 9 V battery for very long, so I don’t think your numbers are realistic. Basically, the battery will overheat and polarize (be rate limited at the electrodes). It is basically the power issue, as @DavidWhite commented.
– Ed V
Commented Jan 3, 2022 at 20:34
• Your estimate for human resistance is quite low, on average the resistance of a (dry) human is more like $1 \text{ M}\Omega$ if the leads are directly attached to your outer skin layers. Commented Jan 4, 2022 at 2:21