Alternator charging lead acid and AGM batteries?

Is it possible to have the alternator charge both the lead acid starter battery and auxiliary AGM battery?
I’d like to use a 100ah AGM auxiliary battery while keep the stock lead acid start battery but according to some research the AGM will require more voltage to charge I’ve also read that it doesn’t matter and the alternator will charge the AGM just fine.
My old set up was a 100ah lithium and Renogy DCC30S controller in the bed, it worked great but was a semi permanent set up so I had to keep the shell on, now I want to move everything under the hood.

 

Expensive but it's the right way to do it and can give you ideas:

https://offgridpowerproducts.com/co...acoma-trd-offroad-trd-pro-dual-battery-system

 

I looked at that and it’s similar to my Lithium set up, I guess the problem I’m having is having a sheltered spot to mount the controller, my Renogy will work with an AGM but I prefer not to have the cables running into the cab and I don’t think it would last long under the hood

 

Easiest would be to go both AGM. You could get a tune like OTT for your vehicle taking into account your tires/gearing. The tune has a setting where it will make the alternator crank about 2-3ish volts higher accommodating the AGM batteries. You would need to say that is what you want to the installer of the tune. Kind of a plus/plus you get a better feeling drive and the ability to handle the AGM. I've had mine like this for some time no issues. I'm only running one battery. I am not knowledgable on the 2 bat set ups.

 

There's a lot of discussion about the needs of AGMs and if the stock Tacoma alternator voltage is enough or if a bump in voltage is better. I've come to believe there are pros and cons to each approach. I have dual AGMs via the Off Grid Engineering setup and I had the voltage on the alternator turned up to about 14.3v. The setup charges the starting battery via the alternator and the aux battery via a Redarc BCDC charger, set specifically for AGMs. I have a dual display that shows voltage on each battery and it's interesting to watch it. Obviously the starting battery is charged continuously at 14.3ish, but the Redarc BCDC varies in voltage and is infrequently that high. It's usually low to mid 13s, with just an occasional 14.3 spike. If you don't want to go all in on the OGE setup, the Redarc charger should still be considered as part of you setup. Mine is mounted near the starting battery and it's a rugged piece that doesn't need to be inside.

 

The Redarc is what I’ll be using, so glad to hear it’s working well for you. What brand batteries are you using and what AH is your auxiliary? Seems I can’t find anything larger than 75AH that will fit the aux tray

 

I'm using Full Throttle Group 35s, with 64AH for both.

 

For those with an Off Road or Pro what are you using for a passenger side battery tray? Are you fabbing your own or using something from Rago or ?
I’m probably going to use my Renogy controller since I already have it and just mount it in the cab, lots of room with the back seats out