Every circuit needs a power supply. One way we will power our circuits is using our battery packs. We are using standard commercial AA batteries. You can get them at the grocery store, the hardware store and countless places in between.
This Building Block will show you how to properly set up a battery pack and emphasize proper battery handling and safety.
Required Parts
- battery holder
- wire ended battery clip
- AA batteries ( brands will vary )
Safety First — Batteries should NEVER get hot
In the world of batteries the ones in your kit are stable and safe — but you still need to be paying attention when working with any electronic circuit.
You should be able to rest your hand on your batteries at all times. If it feels hot enough that you have to pull your hand away ( hot like fresh coffee ) — disconnect and check.
Video :: Setting Up Your Battery Pack
Did you load those correctly?
REMEMBER to triple check your battery polarity (arrangement in the battery holders). Plus side of the battery with plus mark in the holder. Flat side of battery to springs. When done properly, your battery labels will run in opposite directions. If labels read all the same way they are wrong and need to be corrected.
Remove batteries for your commute!
Batteries should never be left in pack for extended periods of time. Get in the habit of disconnecting batteries from circuits when you are done each day. Finally — remove at least 3 batteries from your holder when travelling to and from school or closing up your kit.
One More Time — Batteries should NEVER get hot
If your battery pack ever feels hot to touch
DISCONNECT IT FROM YOUR CIRCUIT IMMEDIATELY.
A hot battery pack almost always indicates that you have accidentally built a short circuit — a direct connection between the plus and negative sides of your battery.
When the plus and negative sides of a power source — such as batteries — are connected together without any other components between them, the power drains VERY fast and the supply will get REALLY hot.
Students who ignore this rule have melted their battery packs and in extreme cases exploded batteries. When batteries get very hot they produce gas and this gas causes the battery case to rupture.
What to do if your batteries explode
Battery pack meltdowns are rare — but unforgettable. They happen to everyone if you work in this space long enough.
The chemical inside ‘AA’ batteries is a kind of lye and is chemically basic. If the battery chemicals get on your skin, rinse very will with water. Once rinsed with water, you can neutralize with lemon juice or vinegar.
If on campus alert staff and they will assist your clean up. If you are at home, seek help as required.
Some pro tips from the pink bunny on what to do if your battery breaks or leaks.