New Lithium battery

Mikee, you could do much better than the Itech 120X, if you wish to upgrade to lithium batteries. Most, if not all, drop in lithium batteries have built in BMS! And the 120X is around 95Ah capacity, though the model number would have many believe it to be 120 Ah.
If your current set up suits what you need, then a new pair of AGM's would suit you, at a lower outlay.

Bob

The main issues with your chargers are that they will have a higher float voltage than what is desirable for a Lithium battery (No float at all or a low float voltage of 13.5V).
If you are going to spend those dollars on a Lithium battery I'd suggest at a minimum you should upgrade the solar controller to a quality unit like the Victron. They are not that expensive.

And if you want a good battery at a great price can I suggest getting the Renogy 100Ah with Bluetooth - they are 20% off via Ebay until 30/11/22 - will cost you $618 I have fitted a couple for friends and they deliver a full 100Ah and the bluetooth app works well to give you an accurate state of charge (without having to install a shunt monitor).
I have measured other cheap ($400-$500) Lithium and while they work well they are often 10-15% less than stated capacity.

Hi Mikee5,

I would humbly suggest that for either set up, (LiFePo4 or AGM), you a have less than half of what you should have in solar capacity, for off grid camping. A good rule of thumb is that for every battery amp you have, you need double the watts of solar capacity. So, for your current battery capacity of 200 amps, you should really have 400 watts of solar capacity. If you are constantly moving every day, and only staying in one spot overnight, you can get away with less solar capacity, as you are continuously topping up the batteries when driving. However, if sitting stationary for several days, your batteries will not fully recover during the day.

As far as replacement batteries are concerned, again, it depends on how you camp, and what your electrical requirements are. If only stopping overnight, and not looking to save on weight, AGM’s will do the job. If however, you are looking to save weight, or looking at staying stationary in one spot for several days, particularly if you have a compressor fridge, you will benefit from swapping over to LiFePo4 batteries. They can be discharged deeper, and with enough solar capacity, will recharge faster. Of course your solar panels need to be in full sun all day.

Every LiFePo4 battery will benefit from a dedicated LiFePo4 profile charger.

Macca.

If your going to own the van for 11 years and deeply cycle the batteries every day then LFP seems the most economic way to go.
As said before if your AGMs are serving you well stick with them.

In reply to your original question, stick with AGM’s.
If you go with lithium, your chargers aren’t compatible.
If you have the room, go up to 120 a/h batts and increase your solar to 3 x 80W.

On a nice sunny day, I like to have the batts on float by midday.

https://voltx.com.au/products/voltx-12v-200ah-basic

These have excellent reviews and would of been my choice except needed one in a hurry so went and bought off the shelf at RTM

Been running Lithiums with a variety of chargers for many years with no issues. Any charger with an AGM or GEL setting is generally ok. GEL settings on the chargers I have with a specific Lithium profile are the same as the LIthium profile.

Personnally I generally use the power supply mode on my A/C chargers to charge the batteries most of the time. Occassionally will charge using the AGM profile to let the cell balancers do their thing.

On the solar and DCDC even though they have Lithium profiles I prefer to use the user setting the charge voltage to around 14.4V for cyclic charging ie same as AGM profile. Batteries around 8 years old and still test above their rated capacity.

Car Lithium is charged directly off the alternator and no issues with it either. Charging can be as simply or as complex as you want it to be.

Going from 200Ah size to 120Ah might leave you a bit short if it happens to rain for a day or two.