ElectricGod wrote: ↑
Feb 20 2018 2:17pm
see those 2 solder holes at the middle, right hand edge of the board? That's P-. Connect your EV here. If you care about having mosfets that control charge then run your charging port to C-. I'm never concerned with charge current. AT it's best, it's maybe 50% of discharge current so I never use C-. Charging and discharging for me always go through P-. Also, if you use regen, that happens through P-...that's just a form of charging. If that's safe through P- and it is, so is regular charging through P-. For the super safety conscious types, C- might have a place in an EV, but more most people it's completely extraneous. Never power your EV through C-. It can be done, but you double the mosfets in series and the related losses. What's the point in doing that? Why they show powering the EV from C- is a mystery to me. I sure wouldn't do that! I'd prefer to have all those wasted C- mosfets on the P- side where they actually matter.
Of course I've connected up BMS wrong before too. This is a couple of 16S 50 amp BMS that are currently in use and connected via the C- port, not P- (center solder hole)...DOPE! It works, just not optimal.
I'm interested in using the charge termination to limit charging to lower than the standard charger output (or above what it's set to as an additional safety net).
I also have an interest (like one or two other posters here) in using these with lithium based renewable energy systems where having separate load and charge disconnects is very useful.
I hope to try and trace out a partial schematic for this board over the weekend to make sense of the implementation.
As you say, they seem to be recommending running power through both FET banks, which is not an optimal solution.
Also, it seems strange that both FET banks drains are connected together while the load current is expected to pass through them in series.
Does this not mean the charge FETs are reverse biased?