I have a SP10V3 with the included Sofirn Rechargable battery and while I absolutely love the brightness and ease of use for this light, the battery dies on me after around 15 minutes at the second lowest power setting. Is this normal life for this sofirn rechargable battery? If not is there a new rechargable battery I can use in it that would last longer?
No, this is not normal. Either the battery or the flashlight is defective.
You will need either a button top 14500 Li-ion battery or an AA NiMH battery.
How did you charge the included battery? What voltage does it have?
It’s a 3.7V 900mAh battery that I charged using the included charger from Sofirn. This happened on both my SP10V3 using both the included batteries and 2 separate chargers.