Bought 600 watts of solar with a 40 amp charge controller, and a decent 400 watt wind generator that comes with its own charge controller with dump.
I'd like to have them both charge their own set of batteries, that will run one inverter to power a 14.5 cu ft fridge and 5 cu ft chest freezer (maybe not in the winter with less sun), and a couple small 12v loads.
I see they make other charge controllers that can do everything, but since the systems come with charge controllers for essentially nothing over the cost of buying panels by themselves, would like to make use of them. And it makes sense to me to separate the systems, so if one battery goes bad, it doesn't take down the entire bank.
My idea is run 2 sets of batteries into a single battery that runs the inverter. The 2 sets of batteries would have a diode that only lets the sets charge the running battery, but won't receive power back from it. That way, if the wind generator is spinning away during the day the same time solar is kicking out max power, the charge controllers can work independently of each other and not overcharge or get confused by charging voltage of the other controller and not put out any charge. And if only 1 is kicking out power, the running battery should only draw power from the bank with higher voltage (?)
Would this be a good way to go? Am I overthinking this and just connect both controllers to 1 battery bank? Should I be looking for a controller to switch between banks that controls relays?
Quick drawing of what I'm thinking.

That looks unnecessarily complicated.

Your battery capacity also seems pretty low for the amount of charging wattage that you’ll have available and for the size of the inverter you’ll be running.

A basic MPPT charger isn’t unreasonably expensive and would be much more flexible.

Inverter is oversized a bunch, I figure the fridge will run 8 hrs a day at compressor rated 200 watts (plus fan and led lights), and chest freezer less hours a day and I think 300 watts. But oversized to safely handle starting watt surges, and intermittent heavy non regular loads but not steady and nothing planned right now. Batteries should be good for 1 full day if not 2, depending how much that chest freezer runs and the power losses between inverter and batteries.
Thinking I should up battery capacity right away? Now is time to do it and no strict budget.
Connected to the grid, and have some experimenting and playing around to do to see how much it'll run throughout the year and add to it as required.
Can get the charge controller to combine both, just wondering if this is something anyone else has done. Or maybe too much and dumb.

I am building something similar, consider a different battery chemistry.

More battery capacity. Also most solar rarely makes rated output. Same with most wind. I thought about fooling around with wind driving a large truck alternator to see how much power it would make

As long as the batteries are matched, I would combine into one bank.
I would keep the two controllers and let the systems operate independently (up to where they connect to the single battery bank)

Like someone else already said, spend some time researching lithium batteries.
The initial sticker shock will surprise you, but if you really look at the numbers like discharge rates, life cycles, etc they are cheaper, smaller, lighter…..

Well lithium is a tough pill to swallow for a hobbyist learning system. Unless someone has a really good source, will have to hold off on those until they become more commonly available.
Right now, I can go to any parts store, walmart, and SHTF scenario, thousands of cars to get a replacement battery. Finding lithium close to me will be a challenge even without any happenings in the world.
Still thinking about 2 banks, 1 running battery. 2 banks bump up to 400 ah per set (6x the walmart 24ms sized marine). Combined with a running battery, should be up around 900 ah. Trying to build in a "2 is 1" mentality within the system, so that if solar or wind charge controller takes a crap, the damage will be limited to that particular side.
Fridge estimated to take about 1900 watts a day, and the 600w solar best I can find produces about 3000w per good sunny day, wind is pretty good here but could be a few days without, so those few days are going to need the extra capacity to run freezer as well as fridge. It just may not handle both loads considering the losses from inefficiencies.  But if grid goes down in the winter, refrigeration can be moved to the garage and will take much less power. Or just get a 12v charging system hooked up to a small engine and use it to charge system when it's dreary and still outside.
70 amp diodes seem to be very common, running battery will draw from whatever bank is doing better at that particular time, and should both drain evenly when not producing.
My concern with hooking both charge controllers to the same bank is when one is putting out 14 some odd volts, the other controller is going to see that voltage and dump the power thinking the battery is full, instead of putting all the amps it can into the depleted battery. I'm far from an expert on the subject and maybe that's overthinking it. But I also fear one of the controllers taking a crap and dumping overvoltage into the batteries which would limit damage to only half the bank if they're split up.
When the roof is replaced we'll likely get a big boy solar system with lithium storage. 5 years timeframe. Want something quick and working should something happen before then. We still have gennys and even a diesel pickup hooked up with extra RV batteries and inverter as a last option.

“Marine” batteries are usually dual-purpose batteries. If you want deep cycle batteries, then buy some deep cycle batteries. If you’re going with lead acid, why not just pick up 4-8 golf cart 6V batteries and series-parallel as needed for 12V? You’ll have “extras” if any cells go down, you can reconfigure as needed.

I’d go with lithium cells if I was building a setup like you’re planning. I haven’t done so yet but likely will build a little off-grid/battery backup setup with cells similar to those posted above within the next few years. This website is highly recommended from elsewhere and has a wealth of knowledge on DIY setups: https://diysolarforum.com

If you're dead set on lead/acid, I would take the above advice and go with golf cart batteries., they will stand up to many more cycles.

I am not a solar expert and I am sure that I am doing everything wrong but for years I have run an 11 cu foot fridge with three 100 watt amazon solar panels, an elcheapo charge controller, 2 8d truck batteries and a 3000 watt pure sine wave inverter.
I used a 1500 watt modified sine wave inverter for a few years till it died. The fridge and the batteries seem to like the pure sine wave inverter better.
What you are proposing looks like it should work to me but what do I know?

This looks like a simple plug and play system, I am sure there are others like it.

Hybrid controller

Lithium is tough on the wallet on the front side, but better long run. And a lot more forgiving if you don't watch you discharge level. Just need a temperature controller so it doesn't charge if battery is below 32 deg.

A 24v system is more efficient also.

At our cabin, I have a 24v lithium solar set up with an inverter/charger. I can plug my genny into it and it power house and charges batteries when running. It switches automatically to battery if genny is off.

Travelled into town to make a Costco run and they had these interstate 6v GC2 batteries for much cheaper than I was expecting. Got 4 for now, to go with the 2 marine deep cycles I picked up at Walmart. Guessing capacity should be good.

Please don’t wire those new batteries together with the marine “deep cycles.” Different capacities, age, ability to take charge, etc. Wire them in completely separate banks, not connected at all, and truck on.

Don't tie the cart batteries to the boat batteries.
It'll shorten the life of the bank.
Just use different systems, load side and supply side.

Got it. Thanks. Can use the marine batteries in a pallet stacker instead.
Went ahead and ordered that hybrid charge controller that combines wind and solar. The controllers that came with fan and solar panels will go in a drawer as backups.
Still waiting on a few pieces to arrive in the mail, and will get to work wiring this all up. For these panels will be building a little "dog" house with panels on the roof, will double as a little shelter for the generator or a parking spot for the mower.

Been researching a lot on batteries. Certainly see why lithium is the way to go, that will be a upgrade in the future, perhaps an entirely new/separate system. Going to wait a while to do it, want to figure out some things first, charging and discharging year round to properly size a larger system. Figure things out like if the batteries are topping off before noon every day, perhaps I need more load, and if the batteries can't handle keeping that load over night, more batteries. Ideally would want to size it so batteries stay above 70% at all times during normal weeks. If there's a forest fire and the sky is grayed for weeks at a time that would be an outlying situation.

Whatever seller on Amazon created a label for the solar kit and hasn't actually shipped it for 3 weeks, so went ahead and got refunded for that order. Just bought the solar panels by themselves, for a total of (8) 100 watt panels which I can expect will produce about 500 watts of power. Already got 2 and was interesting to test outside in the sun.
Those will go to that hybrid 600 watt solar, 800 watt wind controller to combine the solar with the 400 watt wind turbine. Will be charging 8 golf cart batteries, into a 2200 watt (4400 surge) pure sine wave inverter powering a 300 watt fridge an estimated 8 hours a day and a chest freezer that uses about the same. And should have some reserve power to run another load in the summer. Or intermittent loads, maybe we need to vacuum during a power outage...
Now I'm wondering what to do about the batteries. They should be fine in the garage. It's insulated, and plan on keeping it above freezing in the winter.
How important is it to vent these batteries? I'm guessing the max charging power the system will produce on a windy and sunny day is 800 watts. 800 watts into a bank of 8 batteries shouldn't be any where close enough to really get these batteries gassing much.
I mean, I've been charging a electric forklift with vented batteries in a small warehouse for years without noticing an issue, and millions of others do the same with electric golf carts and forklifts around the country without venting. So should I be concerned? Maybe even put batteries in the basement?