BD135 battery charger for 8.4V/150mAh battery

Thread Starter

vrfood

Joined Feb 5, 2016
3
Hey guys. Long story short, i built THIS schematic, using a BD135 transistor, to charge a 8.4V 150 mAh battery with. I am trying to figure out the exact value resistor (R2) I need to use, in order to get a 15mA current (to be in the 1/10 rule).

p.s. i figured somewhere around 220-240, but i am not sure. For some reason my DMM won't measure it correctly

Cheers
 

Thread Starter

vrfood

Joined Feb 5, 2016
3
Since i could not find a 78 ohm resistor anywhere locally, i used 3 x 27 ohm 1% 1/4W resistors, soldered in series, to get a close enough value. Measured it at 80.8 ohms. I suppose that should work.
 
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