#+TITLE: AA and AAA battery tester
#+AUTHOR: Svjatoslav Agejenko
#+LANGUAGE: en

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* General
+ DISCLAIMER: I DO ELECTRONICS AND 3D DESIGN SOLELY AS A HOBBY. THERE
  COULD BE ERRORS THAT CAN RESULT IN ALL KINDS OF DAMAGE. USE THESE
  DESIGNS AT YOUR OWN RISK.

+ This design is released under Creative Commons Zero (CC0) license.

+ Author:
  - Svjatoslav Agejenko
  - Homepage: https://svjatoslav.eu
  - Email: [[mailto://svjatoslav@svjatoslav.eu][svjatoslav@svjatoslav.eu]]

+ See also:
  - [[../../index.html][Other physical projects in this repository]]
  - [[https://www.svjatoslav.eu/projects/][Other projects hosted at svjatoslav.eu]]

* Project description
[[file:make.png]]

[[file:make,%202.png]]

Simple rechargeable Ni-MH battery tester. The problem with those
batteries is: right after you take them out of charger, voltage level
at their terminals is good. But some old batteries will get
empty/discharged way too quickly under normal load. This device is
intended to discover old batteries with reduced capacity.

Freshly charged batteries are tested under high load by shorting
battery + and - terminals using 5 ohm power resistor
(R1). Simultaneously battery voltage is being measured while under
load.

[[file:electrical%20schematic.png]]

I use vintage analog voltmeter. Instead of power resistor I use
Nichrome resistance wire. It gets hot quickly!

+ Body: [[file:body.png]]
+ Cover: [[file:cover.png]]

+ Download:
  + [[file:bodyAndCover.FCStd][FreeCAD project]]
  + [[file:body.stl][body STL file]]
  + [[file:cover.stl][cover STL file]]