Replacing the battery of an MX Keys is one of the most cost-effective repairs on this keyboard: a €9.99 battery, half an hour of work, and the keyboard gets its battery life back. Logitech does not offer this service, but the battery is reachable once the case is open, without touching the keys: the six case screws are hidden under the rubber feet. This tutorial walks through the teardown step by step, with the pitfalls to avoid: a clipped and glued case, a fragile connector, a battery held by adhesive.
Diagnosis
When to replace the battery: battery life drops to a few days without backlight, where a healthy keyboard lasts months; the keyboard shuts off as soon as the USB-C cable is unplugged; or, a danger sign, the battery swells and lifts the centre keys. If it is swollen, handle it with care: a swollen lithium-polymer battery can catch fire if punctured. Never try to puncture or crush it.
How to fix it
- 1
Turn the keyboard over and peel off the rubber feet: the six case screws are underneath. There is no need to remove the keys.
- 2
Undo the six screws, then slide a plastic pick along the edge to release the bottom case (clips and adhesive). Go slowly and never pry with a metal tool.
- 3
Locate the battery under the metal plate and unplug its connector by holding the connector itself, never the wires.
- 4
Peel the battery off with a plastic spudger: it is held by double-sided adhesive. Be patient and do not pull hard, or you risk puncturing it.
- 5
Fit the replacement battery in the same place, plug the connector back in, close the case, refit the screws and stick the feet back on. Plug the keyboard in over USB-C for a first full charge.
FAQ
What tools do I need to replace the MX Keys battery?
A precision screwdriver that matches the case screws (check the head before forcing it), a plastic pick or opening tool, and a plastic spudger to lift the battery (€2.50 in our catalogue). Avoid prying with metal tools: they mark the case and can cause a short circuit.
How long does the replacement take?
Allow half an hour for a first teardown. The slowest part is releasing the case without forcing it; the keys stay in place from start to finish.
What do I do if my battery is swollen?
Handle it with care. Never puncture a swollen battery. Store it in a non-flammable container (metal tin, terracotta pot) until you can take it to a collection point. The replacement battery must not be swollen on arrival: if it is, contact us for an exchange.
Can I charge the replacement battery before fitting it?
No. The battery is designed to be charged by the keyboard's own circuit, which manages voltage and current. An external charge can damage it or create a fire risk. Fit it first, then charge the keyboard over USB-C.
Is the MX Keys Mini battery the same?
No. The MX Keys Mini has its own battery, sold separately at the same price (€9.99). Pick the one for your model.
Six screws under the feet, a €9.99 battery and half an hour of work: your MX Keys gets its battery life back. It is one of the most cost-effective repairs on this keyboard.