I have 1 lead start battery 100Ah and another Service LiFePo4 150Ah on a boat and I am trying to regulate the current coming from the alternator to charge my LiFePo4 150Ah 12v service battery with a constant current of 30A. They are currently connected via VSR, and the maximum charging current is 20A and drops to 10A as the voltage increases, even though the battery is relatively empty.
I would use the LiFePo4 curve for charging, but I don't want to overcharge the starter lead-acid battery. Both batteries are connected with the negative poles.
Can someone kindly explain to me which Charging booster would be suitable in my case?