Why exactly does battery corrosion happen in toys?
First, batteries contain an acidic or an alkaline solution which is corrosive in nature and can be quite destructive to the metallic terminals of toys and other electronic devices, such as television remotes.
Second, the solutions contained in these batteries, which make them transmit current in the first place, are susceptible to leaking. This mostly happens in cases where toys have not been used for some time or batteries have not been changed in a long time.
Why do Batteries Leak?

The main reason for these leakages is the simple fact that batteries discharge. There is a bit of science to this phenomenon, and it is important that you understand how it takes place.
Left over time, the chemistry of the batteries undergo some changes and hydrogen gas is produced. As the battery continues to produce hydrogen, the gas finds it difficult to escape given the fact that batteries are air-tight.
This causes swelling from within thus exerting enormous pressure on the battery casing. This pressure ruptures the insulating casing at the ends or the external metal canister and creates an escape route not just for the gas but also the liquid content of the battery.
It is this leaking solution that causes corrosion of the terminals.
How to Clean Battery Terminals on Toys
When either the external metal canister or insulating casing has been ruptured, the solution begins to leak out into the toy compartments meant to hold the batteries.
If not stopped in time, the acid/alkali can corrode the terminals thereby preventing power transmission from the battery to other electronic sections of the toy. If you want the toy to be functional again, you need to cautiously remove the corrosion.
However, be careful as you do this because the solution contained in batteries can be dangerous, and can be harmful to anything on its path including you.
Precautionary measures must be taken while removing this corrosion since any contact with the acid/alkali will mean damage to your skin. Removing this erosion is simple and safe to do if you are cautious.
Like most DIY jobs, cleaning the battery terminals on toys requires a step-by-step guide, and also some specific materials and equipment.

Requirements
The recommended steps on how to clean battery terminals on toys
I hope that this article has been helpful, and you now know how to clean battery terminals on toys. If there is anything I have missed or you have any questions, let me know in the comments!
Resources
Vinegar is acidic…. not the “opppsite PH to the acidic content of the corrosion.” In fact, the corrosion in toy batteries is a base, hence the name “alkaline batteries,” so vinegar is a good cleaning solution. Acid batteries, like car batteries, should be cleaned with baking soda.
You are correct, the batteries used in toys usually contain alkaline and not acid. I think using the term ‘acid’ is what most people use when speaking about batteries, whether they have an alkaline or an acid solution, but I understand how confusing this may look.
Thanks for your feedback, I have updated the article to ensure the message is more clear!
What if the corrosion of the batteries caused rusting on one of the terminals? I bought a toy from a thrift store where there are no returns or refunds. The batteries leaked in the toy, causing rust on one of the terminals. How do I get that off?
Hi Autumn,
If you are sure that it is rust (red/brown in appearance) and not corrosion (which can be white in appearance), then one way to remove it is with sandpaper. Rust will prevent the battery from making contact with the metal connector of the toy, so keep sanding it until the rust has gone and you can see the metal again. If it is a small compartment and you are struggling to fit the sandpaper in, you could always use an emery board (cut down to size if needed).
Hope that helps!
The picture in this article can tell how dangerous the corrosion of the batteries can be.It look very horrible.I am glad that I came across your article .This article will be really helpful in future if like this type of situation take place.Thanks for sharing this article .
thanks for your for effaced, everything turned out great wearing gloves is a great thing!!