MT99 Multimeter battery mod

thingiverse

<h1>Revamped MT99 Multimeter Power Solution</h1> This is a cutting-edge back cover replacement for the Mustool MT99 multimeter, also applicable to the MT77 and MT99PRO models. I was dissatisfied with the battery life provided by the two coin batteries, so I designed a modified case that incorporates a rechargeable battery, power charger, and voltage booster as needed. The frame is spacious enough to accommodate any battery up to 47 mm X 47 mm x 8mm thickness when using the covered version. I've also created an alternate model (edge), suitable for use with the original back cover. This variant offers approximately 13 mm of clearance around the battery, making it a more convenient option. To ensure proper alignment and prevent damage to the USB cable port, you will need to add some supporting structures depending on the print position. For added convenience, I've included cylindrical geometry supports at the corners that align with the back screws. This allows for easier hole drilling without compromising the infill material. Additional details can be found on my comprehensive Instructable: [https://www.instructables.com/id/MT99-Multimeter-Battery-Mod/](https://www.instructables.com/id/MT99-Multimeter-Battery-Mod/)