Automatic Charging Relays for dual battery system

Reading the dual battery posts like this
https://www.tacomaworld.com/threads...ts-see-them-multiple-batteries-thread.295653/
and am wondering what, besides a remote isolation controller switch (and price), is the difference between using one of these:

$96 Blue Sea Systems 7610 SI-ACR Automatc Charging Relay - 12/24V DC / 120A

https://www.amazon.com/Blue-Sea-Sys...e+seas+acr&dpPl=1&dpID=51uKM7X4wwL&ref=plSrch

vs

https://www.amazon.com/Blue-Sea-Aut...e+seas+acr&dpPl=1&dpID=51-5jdsezAL&ref=plSrch

for using it to keep a double battery system charged with my truck? The price difference is a lot, so I’m wondering if the less expensive SI-ACR will work. I want to use the second battery for accessories such as a winch, diesel RTT heater, etc.

 

Since I am researching a similar thing I came across your post. Sadly no replies...

Did you ever find out/install something similar?

$96 Blue Sea Systems 7610 SI-ACR Automatc Charging Relay - 12/24V DC / 120A

https://www.amazon.com/Blue-Sea-Sys...int=&hvlocphy=&hvtargid=pla-570648928063&th=1

I was wanting to put in a second battery for HAM, lights, fridge, etc and this looked like a good solve (vs expensive commercial dual battery systems). Another question is can I have dissimilar batteries connected (ie, OEM start battery and add something like an Oddysey AGM and isolate/charge through an ACR). Reading elsewhere looks like it is OK, the ACR isolates and charges as needed.

Am reading through the 127 page Dual Batteries post now ...

 

I have the SI-ACR controlling a deep cycle battery with stock main battery. I'm using a marine battery switch to combine/isolate the batteries. Would be nice to have that switch inside the cab, but if I need to combine the batteries, I'll take the time to open the hood.

 

There are lots of options that will work. My motorhome uses a simple starter style solenoid to isolate the house battery from the starting battery. It gets triggered by the charge output of the alternator. There are diode style insulators and newer smart insulators. They will all do the same thing. They just do it a bit differently. Budget will ultimately be the deciding factor but you can't go wrong with any option. The solenoid on my motorhome is 31 years old and still functions fine.

https://m.littelfuse.com/industries...ttery-related-products/battery-isolators.aspx