question

You are going to be way over the 1600 VA that inverter can provide with both of your named loads in operation simultaneously. If you can manage the loads so both don't run at the same time, then you'd be VERY close to the max (1400 vs 1600).

As far as the battery bank, you need to do as energy calculation (watt-hours) for the period you won't have solar energy and/or grid. As an example, lets say your fridge runs 50% of the time, the water heater runs 20% of the time and your DC loads are 10% at 16 amps. That's about 7,500 watt-hours per day. Further, assume you have enough solar to recharge your batteries every day and can go on grid on cloudy days. So your 12 volt battery bank would need 630 USABLE AH. If these numbers are close to your actual needs, I'd say you have about 1/4 the amount of battery storage you'd need since you should only draw down an AGM to 50%.

You can probably count on at most 8 hours of solar each day, so you'd need 1200 watts of solar to refill the batteries each day. I'd say you are too close to the specs on those panels also.

But do the math on your actual daily energy needs and go from there.

Thankyou.
The things i can change with configuration are :
1) I could install a load monitor and switch the hot water heater on to gas to remove that load or simply keep it turned off except for hot showers in the evening.

2) i could change the batteries to 3 x 170 AH (i have one the same type and age).

3) i could upgrade the Multi to a 12/2000/80

I am still stuck with the same 1.4 kW solar due to space , does the above give me a healthy happy configuration rating ?

What would the experts tweak for optimisation ?

If you are wanting to use the heater for hot water off the solar it is better to run the heater in peak sun for that, not off the batteries in the evening.

2x 170ah agms can give (12x2x170) 4080wh of power at their c rating to full depletion which you never want in agm. So to 50% you have about 2 useable units of power without causing damage. This does depend on your current batteries health though these are calculated for new ones.

You need a high amperage mppt chargers for keeping up with your charging and some smaller loads. But since you are limited for space 1400w÷ 12 = 116A of mppt if possible so two 100/50 maybe? But remember agms can only charge at a certain rate the bank you have most likely wont absorb the whole 100A so limit the system charging in dvcc or with a gx.

This should help you get your 2 units back into the battery and run a decent load in peak sun. Depending on how hard you are working the system. A 12v system can get 3 to 4 kWh of power a day a little more in some seasons where we are. Sometimes 6 kWh

Fyi my fridge uses between 1 and 2 units of power at night depending on what season i am in, it is a full size fridge though. If that helps with the evening calculations.

As Kevin was saying, you need to work out some things on your own. Also get some good monitoring as well. And run short and as large as possible cable to your batteries to improve efficiency.

I would think the very best thing you could do is CHANGE to lithium storage, you only need ONE 200 amp lithium battery and that gives you more usable power than 2 of the agms combined and if the agms are older than there capacity is maybe way lower than 170, also the lithium's will take all the charging you can throw at them. they are 25% at least more efficient as well, and last soooo much longer - as a example

if you take 100amps out of a LA battery you have to put 125 amps back in and also slowly and it takes 8 hrs to fully refill them

A lithium if you take the same 100amps you have to put back 105 amps plus you can put that fill 105 back in 1 hr

there are so many advantages, and the costs are similar if you are buying the SAME usable capacity size. and you then also have way more options latter on as well.

You would then see a huge system change in how things worked as well, - and

from your figures the max 220v load is 8.7 amps so thats only 1900 Watts plus the 16 amps of 12 volt load you could put the hot water system on the AC2 out connection so that it only ran when on shore power or generator. so a 1600VA unit should be fine, a 2000 is always better and then a 3000 is better again and you may also run the Air con on that as well (only with lithiums though)(depending on A/C size that is, Max 12,000 BTU), but were do you stop. but its worth considering.

you main issue is that at 1900 watt load and thats 160 amps at 12volt and your AGMs voltage will just collapse with that sort of load, Lithium's basically will hold that current draw until they are flat. ie a 200A/H lithium usually can deliver 200 amps for around 50 min as they can be 90% flattened (80% is better but not by much) and then you can recharge them in as short as 30 min if you can shovel the amps in as most good ones can take a 1 or 2 C CHARGE RATE (a 1c is 200 amps and a 2C is 400 amps (based on a 200A/H battery) so 1C is the battery capacity in and out and 2C is twice the battery capacity in and out, some lithium's can do 3Cs.

Anyway have fun and enjoy the traveling