This allows you to add additional space to the back of your LILYGO® T-Echo device to fit a bigger battery. Download the version that gives you the space you need; 3, 4, 5, or 6 mm. The advantage of this model over other ones is this one only adds space between the body and the original cover rather than replace the whole cover.

I'm using a 2000 mAh battery that fits snuggly with the 3 mm spacer.Do note that most of these batteries come with a PH 2.0 mm connector which needs to be replaced with a JST 1.25 mm one. You can reuse the original battery's connector.

I attached the STEP and F3D files so you can make whatever adjustments you need.