# Can I eat the lemons after I have used them as a battery?

After completing the lemon battery experiment, can I eat the lemons when I'm done?

More broadly, what will happen to the lemons? What are the chemical reactions, what chemicals might be present/missing after running my lemons as a zinc/copper battery? Would it be poisonous, or just unpleasant?

• Hmm, a single down vote amongst the ups. Feedback greatly appreciated if available :) – gingerbreadboy Jul 23 '17 at 10:06
• Wasn't me but I'll bet somebody thought there's no way this could be a good idea. The first answer reveals it's nowhere near that cut and dried, so I don't care for the downvote either. – Joshua Jul 23 '17 at 14:49

In a lemon battery, the zinc from the galvanized nail is giving up electrons and transitioning into an aqueous state:

$$\ce{Zn → Zn^2+ + 2e−}$$

While zinc is entering the electrolyte, two positively charged hydrogen ions ($\ce{H+}$) from the citric acid with two electrons at the copper electrode's surface and form an uncharged hydrogen molecule $\ce{H2}$:

$$\ce{2H+ + 2e− → H2}$$

While zinc is a mineral our bodies need, I wouldn't recommend using this as a source of zinc. Also, zinc toxicity is a thing, so without knowing the dose you're taking, you risk poisoning yourself.

Lemon Battery Wikipedia

• Unless you manage to dissolve a significant part of your zinc electrodes into the lemons, zinc toxicity is probably not a serious concern. As the Wikipedia article you linked to notes, zinc supplements containing over 0.15 grams of zinc per day have been commonly used with no lasting harmful effects. That's equivalent to about half a square centimeter of 0.5 mm zinc sheet entirely dissolved into the lemon. Mind you, I probably still wouldn't eat the lemons myself; if nothing else, I suspect they may taste pretty nasty. – Ilmari Karonen Jul 23 '17 at 10:02