Lithium Batteries for caravan

Sapper,
On face value the 120AH lithium at 80% drawdown will give you 96AH. The two 100AH AGMs at the recommended 50% drawdown will give you 100A and will weigh about 65Kg, while the 120AH lithium will weigh about 15kg and will take up a less than half of the space.
A 160AH lithium is about 21Kg and will give you 128AH usable and still take up less space than the two AGMs.
Add in the other advantages of lithium and it's a no brainer really. That's if you don't mind the cost.

As said, apart from the BIG price, which isn't a consideration for you, the Lithiums are a no brainer..

Lithium also require changes to the charging regime, something to factor in if you can't alter existing charging means.

Hi Sapper
I have gone the Lithium way a year ago , and it it fantastic
yes you will have to change the charger, I did away with the setec and put a fuse panel in its place, I just run all from the battery
I purchased a Pro Power 150 ah including their 20 amp charger for $1680 ebay 30/6/2017
This pro power 20 amp charger puts out a constant 14.4 volts
The guys were very helpful when setting up my solar
I have a 30 amp Mason pvw controller, this a programmable type
the setting I changed to .... Lithium from standard
.....................................Lithium.................................Standard...............
Bulk...............................14.4..................................... 14.5....................
Absorb............................14.4.....................................14.6......................
Float................................14.4....................................13.5.....................
LVD..................................13.6....................................13.5.....................
LVR..................................13.3....................................12.5.....................

The battery comes with its own BMS internally .
The battery's ability to accept the charge is incredible .it is so fast
.
We have 340 watts of solar on the roof for the charging and very rarely park where there is power.
I run a 55litre freezer at -12C and a 40litre drinks fridge at 0 C the usual stuff 2 x computers lights ,pumps etc
All I can say it works very well .
We just spent 3 months in the tropics from Darwin to Cairns and all went well
hope this helps out
The BMS work as I made a mistake and left the 3 way on 12 volt ,beware if it drops out you have no power so keep a torch handy
all good it does charge up fast I was getting 17 amps into it from the solar and if you want and have power put the charger on and it will take the 20 amps as well ,it loves it.

Cheers Bob
ps add up your AGMs the extra cost is not that much more including the charger and fingers x if they last the 10 years that people talk about you would be way in front .

My new 200AH lithiums arrived on Friday. Each weighs 27Kg. They have LEDs on each bank which report malfunctions. The little box on top is the battery control unit. Now to install them.