22nd November
written by Todd Harrison

In this video episode I show how to replace solder tab rechargeable batteries in some very useful consumer products that would otherwise end up in a landfill. I use more common and cheaper none solder tab reachable batteries and show how to safely and effectively solder on the tabs.

First up was the solder tab type AA 1.2v Ni-Cd in my beard trimmer. I know, not the most attractive thing a man wants to see in his bathroom.

Then my programmable Christmas tree light timer which needed a coin cell 1.2v Ni-MH with PCB mounting tabs.


I noted in the video that it was interesting they were powering the timer controller using a bridge rectified AC to DC converter.  I was surprised to see this without the use of a step down transformer before the rectifier circuit.  Further research, I found this is quite common in consumer products that require less than 70mA and it can be done safely and cost effectively.  There are some pros and cons to this approach. If you want the full details with the math and picking the correct sized passive devices  you can review this nice article at Microship.com.  For the power conditioning circuit which is closes to what is in my timer see Fig.12 in the article.



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