I am a novice with electronics, I may know what my issue is but wanted to put this out and make sure my thinking is correct.
The below circuit is one I am using to turn on an LED when charging a battery and turn off when the battery is complete for an amplifier I've designed. What is happening is the LED never turns off. 0.74V is coming from a pin on the charging module's IC. When it turns off it is about 10V. This was working fine with a 12v AC adapter as I was waiting on my 15V adapter to come from China. Foolish me, I completed my PCB design and placed the order before I was aware of this issue. Sure I could just continue to use a 12V adapter but the circuitry is more efficient with the 15V when charging and listening at the same time.
I am hoping I just need a different transistor, my current one is a 2N3906. From looking at the datasheet I am thinking my Emitter−Base Breakdown Voltage of 5 is not high enough and if I switched to something like a KSA708 with an Emitter−Base Breakdown Voltage of 8 I may get the result I am looking for with this project. Any insight would be greatly appreciated, thanks.