Marshall monitor 3 battery replacement

Hi @jirihala

Here's a teardown video that may help.

The battery can be seen at 2:34 minutes into the video.

Usually the battery model number or specifications i.e. dimensions¹ and voltage/current are printed on the battery.

Search online using that information to hopefully find suppliers of the battery.

¹ The dimensions of a battery are usually a 6 digit number where the first 2 digits = the depth or height of the battery in millimetres (mm) with a decimal point that is not shown, the next 2 digits are the width of the battery in mm and the last 2 digits are the length of the battery in mm.

An example only (as I don't know what is installed) would be something like 304050 3.7V 1500mAH = 3.0mm H x 40mm W x 50mm L, 3.7 Volts, 1500 milliAmpereHour. Usually they are also a LiPo (Lithium Polymer) Battery type as well. Hopefully this makes some sense to you.

@jirihala

My mistake. Apologies.

Here's a video that may be a start.

It shows how to remove the ear cushions and then once they're removed you can see the 4 screws holding it together.

Usually the battery is located in the side that you plug the USB charger cable into.

Once you find the battery see my initial answer above how to hopefully find the replacement battery.

It seems that nobody has had to replace the battery yet as no doubt this is due to the fact that they are too new. The earphones were only released in Sept. 2024