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Hot swapping Parallel Batteries of Different Voltages

Category: Hardware
Product Number: LTC4260

Hello dear community members,

I am new to this space so I apologise incase if something is not properly followed.

I am building a circuit that can be used for hotswapping of parallel Li-ion battery packs, nominal voltage of 48V. The aim is that the higher battery should charge the lower voltage battery with a constant currrent of 20A untill both batteries can safely power the DC Bus.

I am exploring the options of Hotswap and Current Limiting ICs like the LTC4260 by Analog Devices and I have the following questions / concerns.

  1. My concern is that if both sides are active loads like battery, if one battery is at relatively higher potential than the other one let say Batt 1 is 60V, Batt 2 is 44V and internal resistances of both batteries are 8 milli-Ohm respectively. In normal case the inrush current can be in Kilo Amperes due to high voltage and low internal impedance. Can the LM-5066 or similar IC be used safely for this use case ?

  2. I also want to understand whether it is a good idea to use this type of topology or should I design with a buck convertor method. Because for PoC I am trying to build a 5A Current Limiter with LTC4260 and MOSFETs, where the heat dissipated across MOSFET is coming around 75W.