21700 Lithium Battery Charger (using a Type-C TP4056-1A charging module)

A 21700 lithium-ion battery charger, utilizing a Type-C TP4056-1A charging module (choose the one pictured without battery protection—those with protection are overpriced). While charging isn't particularly rapid, the cost is low. Metal contacts can be sourced from existing 18650 positive and negative terminals or salvaged from AA batteries. I used terminals from AA batteries in a toy my son damaged. An adapter can be used with 18650 batteries; the adapter file is also uploaded and can be found on my profile. Use M2 x 4-6mm screws.