For a project, I have a set-up where the power to the main load comes from either a AC-DC adapter input (24V) or a battery pack (12V to 16.8V - 4S4P 18650 Li-ion cells). The battery pack is connected through a BMS module.
Both power supplies are connected to a switching circuit that 'selects' the right source to use (DC if available, battery otherwise), using the LTC4416-1 chip.
The DC input is also connected to a charging circuit using a DC-DC buck converter with CC/CV limiting to the BMS/battery pack.
For safety, I want to put a reverse current blocking protection between the buck module and the BMS/battery. (To prevent current from flowing back if the DC plug is pulled and thus the buck has no power.)
I've read/seen a lot of posts/articles/datasheets/instruction videos/etc about possible options, but can't seem to find the right solution for my situation (supporting charging current that starts @ 4.08A - 16.8V).
- Specially tailored (Schottky) diodes --> simple/affordable, but a lot of wasted power and heat
- Dedicated ICs (like a load switch) --> can't find one for my specs; either too little maximum current or too low maximum voltage
- High side switch using P-MOSFET(s) or N-MOSFET(s) --> can't find/figure out the correct diagram/circuit logic for this, since they all handle reversed polarity protection, which is not the case here..
My question is: what IC or (MOSFET) circuit can I use to block the reverse current?
NB: Since the whole assembly will be mounted on a panel, there's no reversed polarity issue, only reverse/leak current from the battery to the buck module.