Magic Mouse3 is a non-existing mouse from Apple. When existing, it has certainly a wireless charger on board. When Apple doesn't make one, we makers do. In reversible steps I went from Magic Mouse 2011 to version 2020. In this part 2 we see a way to modify the Magic Mouse to charge wireless a battery. Two parts are important; the Li-ion battery (with build-in charger and over/under protection) and the charge modules with the coils. Except the receiver coil all parts fit within the battery compartment of the mouse.

Supplies

1- Single cell Li-ion 3.7V AA battery, with build-in charger.

2- Charging modules; transmitter and receiver from Seeed Studio.

3- Aluminium strip to connect battery contacts.

4- A micro-usb plug. has to fit within battery compartment.

Step 1: Video Magic Mouse 3

Step 2: Modification Steps

The connection pin from version 2 has to be replaced by an aluminium strip. Now there is enough place for the charge receiver module in the battery compartment. This module has a regulated voltage output of 5V.

The single cell Li-ion battery has a charge controller with protection circuit build-in at an extreem small surface. Only two holes have to be drilled in the battery compartment lid, one aluminium connection strip installed and a micro-usb connector has been made smaller. Also a plastic slide sheet has to be cut to protect the coil at the bottom. On the transmitter side only a usb2 plug is soldered at the 5V input pins.

Step 3: Connecting Parts

We start with desoldering the receiver coil from the module and stick the two ends of the coil through two holes in the battery lid. Then we solder the coil ends on to the board. With 2 sided tape the coil is connected to the lid and the receiver board to the strip. Now the micro usb plug has to be stripped, cut as small as possible, to fit within the battery compartment. The plus and the minus of the plug are connected to the board pins. After the micro-usb is put in the battery opening we are ready to test the charging procedure.

Step 4: Test Set Up

Before starting the load progress test all the parts have to fit nicely within the battery compartment. The wires have to come in place. When the lid is closed only the coil is sticking out. Now we connect the charge transmitter to a 230V netadapter with 5V-1A usb out. When both coils are put beside each other the red charging led of the battery lights up. When the battery is fully charged a green led light's up. All the charging is done completely automatic. The rest current of the transmitter is about 50mA. Charging can start with 700mA, that goes quickly down to 200mA.

Step 5: Conclusion

A downside is that the coil lifts the mouse in the back. That is no problem, as long the frontside stays on the same level. Taking away a part of the black sliders underneath the coil lowers the mouse. This modification works fine. The Magic Mouse reacts after this modification as usual. Only the battery level on the computer is always 100 percent. The charge transmitter can be build in a box or in the mouse pad. Make sure that when the mouse touches the charging pad, the transmitter only turns on. that saves energy. The costs of the charging set is less than $10, the same for the battery.