Help with Lithium battery upgrade

[Roadworrior]

Have a 2021 Georgetown GT5H Motorhome and swapping out the 2 house batteries for 4 lithium batteries.
Not as easy as it should be.
Wanted to know what the 4 fuses on the coach batteries were for and asked Forest River tech and he sent me to a site with specs of the Coach and no useful information.
So let’s see who might have some answers.
Changing the charger converter to a 60 Amp Progressive 9160ALV for lithium
Have the 8421 Precision BCC and ordered a DC toDC 40 Renogy .
Don’t want to burn out alternator or damage chassis battery.
Also ordered a Precision BMI. 225 Amps
Now for some tough questions? What are the 4 fuses connecting to the coach batteries for.
Anyone have any diagram of how they installed a similar lithium battery system?
Did some testing and think from what YouTube had and read if circuits on the coach might be heading in the right direction.
Pictures would help a lot.

[SeaDog]

This is general and not specific to your rig. Fuses off the batteries are normally installed to protect the circuits and the batteries from very high amp draw operations like moving slides.There are experts on the forum when it comes to lithium battery installation who I'm sure will chime in.

[Roadworrior]

Thanks will test them to see what they feed

[JimSt]

Just curious how your upgrade went? I'm looking at similar for our GT 2018 369ds.

My 3 main breakers from SDC-107a BCC go to hydraulic pump(80a), converter/charger (80a) and I think chassis battery (20a auto-reset which I guess would limit my dc-to-dc charger size).

[rk06382]

Originally Posted by JimSt

Just curious how your upgrade went? I'm looking at similar for our GT 2018 369ds.

My 3 main breakers from SDC-107a BCC go to hydraulic pump(80a), converter/charger (80a) and I think chassis battery (20a auto-reset which I guess would limit my dc-to-dc charger size).

I was able to adjust the voltage on my SDC-107a BCC for Lithium.

See:
How to adjust SDC-107A BCC for Battle Born batteries.

I also set my charger float voltage at 13.4v.

I have used this setup for two years. I have seen 90 amps from my alternator charging my Battle Born batteries as I drove down the road.

[JimSt]

Originally Posted by rk06382

I was able to adjust the voltage on my SDC-107a BCC for Lithium.

See:
How to adjust SDC-107A BCC for Battle Born batteries.

I also set my charger float voltage at 13.4v.

I have used this setup for two years. I have seen 90 amps from my alternator charging my Battle Born batteries as I drove down the road.

Thanks, I'd read your thread and pics there are super helpful!

Been trying to decide if the BIM and dc-to-dc charger are necessary in addition to Sdc-107 adjustment. Seems like the latter would prevent converter from charging chassis (engine battery), which I think is how the charge system from factory works.

[JimSt]

Originally Posted by JimSt

Just curious how your upgrade went? I'm looking at similar for our GT 2018 369ds.

My 3 main breakers from SDC-107a BCC go to hydraulic pump(80a), converter/charger (80a) and I think chassis battery (20a auto-reset which I guess would limit my dc-to-dc charger size).

Originally Posted by rk06382

I was able to adjust the voltage on my SDC-107a BCC for Lithium.

See:
How to adjust SDC-107A BCC for Battle Born batteries.

I also set my charger float voltage at 13.4v.

I have used this setup for two years. I have seen 90 amps from my alternator charging my Battle Born batteries as I drove down the road.

Correction: on my georgetown that 20a auto-reset circuit breaker goes to trailer charge line, not chassis battery. Oops and thanks