Hello guys,
I've got a Supermicro Server PSU that I want to modify slightly.. The goal is to charge LiFePo4 Cells with 14.4V and as much Amperage as I can get. The PSU is rated for 75A, while the cells (Headway) allow for 80A max continuous. I'm guessing to keep it safe 64A should be the max. to keep it around 920W as specified.
However, thats all theory, I need to get it working first
The Board is called 35RO-921111-M16F and was manufactured around 2014 if the date codes are to be believed.
I've started to look at the circuit and it seems like a PIC16F1937 is running the show, or should I rather say
ruining it... Apart from that there's only two LM324s, a mysterious 8 pin chip labeled "4424 YM 1401" (One is also on the primary side near the powerMOS so maybe something SOAR related or a gate driver?) and a CM6901X on the secondary side. Messing around on the primary is probably not nescessary as I only need to
slightly increase the output Voltage and fool the PIC into thinking everythings fine.
Also would be cool to have amperage control but that should be rather easy as the ACS756-SCA-100B current shunt outputs a analog signal thats then amplified or comparatored by one of the LM324s, so easy point of attack there. Current regulation seems to be done with a quad of IRF-3206G Hexfets.
So now that you know what I'm up to heres my question for you: It would be of immense help if there was any sort of schematic or service manual available. Even a block diagram would make things a whole lot simpler.
If there's nothing available, and atm it looks like thats the case, I'm going to trace it out but I'm currently not at all in the mood to spend a saturday tracing tiny circuits with lots of vias and such.
And if you think I'm nuts and should stop what I'm doing immediately, here's the backstory:
I want to build a concept ebike, that can charge with up to 10C like the cells are rated for. Basically it would be cool to drive 40km, have a coffe while recharging and then being able to drive another 40km instead of having to wait an hour or more.
This can be accomplished by using EV chargers, they can deliver up to 22kW 3 Phase 230V on a Type2 connector...
However, my main problem is finding a suitable charger that can deliver the 2 to 3kW needed at either 36V or 3x 12V. My idea was to split the pack into 3 groups of 4 cells each and use 12V Server PSUs which are cheaply available and built to last.
But if you've got any other Idea how to achive 3kW at 36V(43.2V) without breaking the bank please let me know!
Looking forward to seeing what you guys think of this!