6.4L Dual Batteries Without Isolator

[DampLemonade]

Single 220a alternator on a 6.4L here. I'm looking to get a dual battery setup in plain parallel for extra CCAs in the winter. I don't need nor want an isolator since the second battery is primarily for startup. The alternator itself certainly shouldnt care about the extra amp-hours to recharge both, but is there any trick to getting both batteries hooked up without making the truck angry? I plan on using some 0ga directly between the batteries' respective positive and negative terminals.

Only reason I'm asking is because my factory battery negative has that IBS crap (pun intended) on it. From what it sounds like in this thread (link), guys running high-amp loads simply bypass the sensor but only because it has a relatively low ampacity. To be clear, I'm not running a large winch or anything, I just read that thread for info on what the IBS actually reports. It would seem I do want the second battery wired in with the IBS so the voltage reported is that of both and not just one battery.

Is anyone here running a dual battery setup like I'm talking about? No relays or switches, just always connected in parallel? Is there a specific way to connect the two to make the truck's sensors happy? Or am I just overthinking it?

 

[johnmyster]

I am foggy on how the charging system responds to the IBS signal, but I would assume that it makes a judgement call on charging current vs voltage, allowing it to make a better assessment of battery health and charge accordingly. If you paralleled a second battery, it would just see it as one big healthy battery. I can't see how it matters either way.

Do the 6.4 trucks have extra space for an larger battery in the tray like the diesels? H8 (grp 49) > H7 (94R) > H6 (grp 48)

 

[jabartram]

I run 2 batteries on a 220amp alt, but i run an isolator.
the issue with running 2 batteries in series, if 1 battery deteriorates, it will ruin the 2nd battery and the alternator will work overtime try to keep both of them alive.

this is the isolator i have run for a few years on 2 different trucks.

https://www.amazon.com/dp/B0058SGDFK?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_6&th=1

 

[DampLemonade]

Do the 6.4 trucks have extra space for an larger battery in the tray like the diesels? H8 (grp 49) > H7 (94R) > H6 (grp 48)

if youre talking about the singular tray from the factory on the driver's side, not really