flippy wrote: ↑
Feb 26 2018 3:08am
just wondering for you math wizards:
how much power does shitty mosfets like the ones mentioned above acutally consume on a decently sized battery (lets say 2kWh) at 48V at 25A continous and how does that compare to the "proper stuff"?
one can spend 50 bucks on proper mosfets on a BMS worth 40 but if the gains are good (or bad) then there should be a transistion point were having good mosfets actually pays off.
Good mosfets always pay off! OK...that was a bit too black and white. hahaha
But seriously, "good" is a matter of perspective. Do Chinese mosfets work? Yes they do. What I can tell you is that Chinese mosfets have much less tolerance for over loads or any form of abuse than the legit parts do. It's not uncommon for Chinese mosfets to be slower or to have a higher Rds or not handle the rated wattage and current of the exact same part from a legit source. The real parts from legit sources will be the best option. I'm a bit of a stickler about components. I have lots of legit IRF4110's that I've pulled out of controllers and replaced with better mosfets such as the AOT290. Can you get away with NOT upgrading mosfets? Sure you can, but if you want optimal performance, then you want the best mosfets too.
The IRF4110 is a decent mosfet, so is the IRF4115, but in my opinion, they are average. There are better mosfets. In 100 volts, the IRF4110 is average, the AOT290 is much better and the CSD19536KCS is the best. In 150 volts the IRF4115 has been used extensively, but it's second best to the AOT2500 which is the best in 150 volts. A controller with IRF4110's in it or IRF4115's get upgraded to better mosfets if I have any intention of keeping that controllert. I want to be able to maximize current handling and reduce heat and losses to the lowest I can achieve. AS a result I build 12 fet controllers that continuously and reliably do 4KW and above. That's what good mosfets get you and what cheap ones will never achieve. In a BMS it is no different and exactly why I pulled the HY3410's out and replaced them!
I mess with LED's a good bit. Chinese XML's, XP-L2's or XHP70.x are crap compared to real CREE LED's. They won't be as bright for the same voltage and current and can't handle any use above specs at all. A real CREE LED can always handle an extra 20% more voltage and that usually means 2-3X more current than spec with no harm to the LED. The Chinese LED's just burn out.
That's legit and good quality parts for you!