MS12 ’s internal active cooling fan is so inefficient & without any cooling fins on outside of the body Which make MS12 a very bad heat dissipation light.
3 minutes internal temperature reach over 100˚C & the handle is way too hot to hold!
That’s not good, the LEDs are probably at 150C+
Thats crazy, its just a matter of time before the leds cook themself and die from extreme heat… 
clearly imalent just rushed that thing and didnt thinkg about the problems in the long run… there is areason olight and acebeam ditched internal fans.
Internal fan is a good move for hot-rod torches, if designed with few consideration at early design stage:
- Thermal shutdown sensor in the driver with or without the fan working.
- IP68 fan with thermal trigger and overload switch. If the fan keeps spinning when suddenly immersed in the water it will robs more power while do nothing to cool the assembly.
- adequate fan with optimal airflow debit
- reasonable airflow, not just stirring the air inside or near the fins with nowhere to go. The air inlet/outlet must be placed in optimal position. Most IP68 micro fan designed to last with no more than 60°C air input temperature. Best to blow cold air than to suck hot air.
In above case I guess the fan was included in the system after the head designed finished.
- Clemence
Quality ball bearing fans can do 50K hours.
Server power supply arrays run for years, I have had domestic computers run continuously for 5+ years in harsh industrial settings as monitoring/control stations.
Quality being the key point, but normal OEM quality delta branded DC fans used in a lot of PSU’s should be capable, and they are nothing special really.
The following contains some numbers, Click Link to ball vs bush fan