If someone has been hurt, deal with that first. For a skin burn, hold it under cool running water for at least 20 minutes — not ice — and take off any rings or watch straps near the area while it is still possible. If battery fluid has got into an eye or onto skin, rinse with plenty of clean water for the same length of time. Get medical advice for anything more than a small reddened patch, for any burn on a child, or for any contact with the eyes, and take the details of the product with you. If someone has swallowed a cell, or a cell is stuck anywhere, treat it as an emergency and go straight to urgent care — do not wait to hear from us.
Then tell us, and keep the device. Do not throw it away and do not post it to us. We need it, and the cells, to identify the batch. Message us here or email [email protected] with your order number and photos, and a person will pick this up — this is not something our chat assistant handles on its own.
If a battery is hot, swollen, leaking or smells sweet or chemical, stop using the device now.
Unplug it from USB and from any charger.
If it is safe to do so, take the cells out. If the battery is built in, do not try to prise it out.
Put the device somewhere clear of anything that can burn, and keep children and pets away from it.
Do not put a swollen or hot cell in a fridge, a freezer or water. Do not puncture it, press it, bend it, or open it up.
Do not keep using or charging a device whose battery has swelled, got hot, leaked or vented.
Do not post it to us or put it in with your household rubbish or recycling until we have told you what to do. Damaged cells have their own disposal rules.
Then message us here, or email [email protected], with your order number and photos of the device and the battery. We will look at it with you and tell you where you stand.
Everyday care
Check the cell orientation against the markings on the board before you power up. Cells put in the wrong way round are the most common cause of a kit getting hot.
Use fresh alkaline AA or AAA cells in the kits that take them, rather than rechargeables. Rechargeable cells give 1.2 V instead of 1.5 V, which is not enough for our kits to run properly. This is explained in Can I use rechargeable batteries in my DIY kit?.
Never mix old and new cells, or different brands and chemistries, in the same device.
Charge Li-Po devices from the supplied USB cable and an ordinary USB power source. Do not charge unattended, and do not leave a device charging overnight.
Take the cells out if you are putting a kit away for a few months. Cells left in a stored device are what usually causes leaks.
If you are not sure whether something is normal, send us a photo before you carry on using it. We would much rather look at it early.