@TajD is right, the batteries he uses work well. I used them for many years.
I switched recently to USB-C charged ones because for me they are a bit more convenient, and they open more flexibility for charging the battery while installed and in use, essentially acting as a “wall adapter” for powering the pulse generator. To do this you need to understand each product manufacturers safety and use guidelines. So for now, I think that niche use is advanced and requires technical knowledge.
4500 mWh vs 500 mAh: these are essentially the same thing because W = A * V …
[a couple of paragraphs of technical jargon… if you already know it there is no need for me to explain, if you do not, there is no point digging through these technical details]
Final conclusion: mWh = mAh multiplied by battery voltage
since it in this case it is a 9 volt battery:
4500 mWh = 500 mAh * 9 = 4500 mWh
same thing, expressed in different physical units (well sort of… in one case the units are explicit, in the other the voltage is implied)
Practical observation and my opinion: that is about the right energy capacity for use in our devices. You could try larger energy capacity numbers, but then you need to fit test the larger capacity batteries to make sure they will fit in the Micro-Pulse generator. Larger number = larger physical battery.
A good guideline is to just avoid trying to buy the most massive energy capacity battery. Just select an “average” one and it usually works well, and sometimes better than the more massive batteries because the manufacturer is not trying to press the batteries to (and beyond) their safe and reliable limits.
