How to Turn an Old UPS into an Alkaline Battery Charger!

I recently lost my collection of electronic components, and was looking for a cheap source of parts I could use in my projects. It turns out that my old, broken uninterruptible power supply was a goldmine of useful components! Check out the video to see what I found inside. It turns out that I had everything I needed to build a battery charger, an audio amplifier, a variable power supply and more.


The charging current = 1.25V / R
For example, I found that the 3 fuses put in series gave me a resistance of roughly 7 ohms. 1.25 / 7 = 178mA. So the battery would charge with a current of approximately 178mA.

The full datasheet for the LM317T can be found here. It contains lots of nifty example circuits. The charger circuit can be seen on page 10.

If you wish, you can support my videos by:
- Clicking this link and bookmarking Amazon’s home page.
(I’ll get 6% of any sales made through Amazon and the price to you is the same either way)
- Browsing my recommended equipment page.
- Support via online donations.