@Thurmond1317, what you're confused by can be difficult to conceptualize at first, so don't feel bad. The big problem I see here is the common belief that devices are 'injecting' or 'forcing' energy/electricity/electrons/whatever in any particular direction. It doesn't really work that way, though the difference is subtle. It's more about energy seeking balance than anything else... flowing to where there's an imbalance of energy until the energy state of all things is the same.
Consider a single battery by itself. If you measure the voltage between the negative terminal and the positive, you'll get some reading (let's just say 12.8V in this case... totally arbitrary figure). What this means is that the energy state at one terminal is much higher than the other. Not connected to anything, there's no path for current to flow to balance these levels out.
Now let's take another battery and hook it up in parallel with that one (like a dual-starter-battery setup common to large vehicles like ours, only in this example not hooked up to any potential loads). Let's say the first battery was at 12.2V, and this one is at 12.8V. What happens? Well... with a deficit of ~.6V, current will flow from the point of high concentration (12.8V), to low concentration (12.2V), until they balance out. For this discussion let's just say they both end up at 12.6V. At that point, current flow stops. They now both have the same amount of 'push' in terms of voltage.
Now let's take the 2nd battery away and replace it with a charger. It doesn't matter if it's a stand-alone charger, DC-DC alternator-fed charger, charging unit of your inverter... whatever. They all work the same (at least in this simplified example). Let's say the charger is set to output 13.4V. What will happen? Well, our remaining battery is now at 12.6V, so energy will flow from the area of higher concentration (the charger), to the battery, until the voltages balance. The only difference in this case is that unlike another battery, the charger has an external source of energy. So it's not going to decrease its voltage output in the process (once again, this is a simplified discussion to illustrate core concepts. In reality a charger very well may decrease voltage as part of its charging algorithm, but that point is moot here, and an unnecessary distraction).
What happens if we set the the charger to output 12.8V, and we hook it up to a battery that's at 13.2V? Will current flow from the battery to the charger now? Yes, it absolutely will, and this movement will be used by the charger to trigger its circuitry to stop producing juice. The internal circuitry will be designed to prevent this current flow from finding ground and thus discharging the battery, but that doesn't change the fact that current will flow from higher concentration to lower... or at least try to, regardless of which 'device' is the source of the imbalanced energy.
Finally, let's take the battery and charger combination, and now hook them up in parallel with a load (as would be the case in any real-world example, including yours). What's a load? Basically, just a path energy can travel to reach ground (aka achieve balance), while doing work along the way. In real world use the load on your system at any moment is the combined draw of everything demanding power at any given moment. But for purposes of example, let's just make it a light bulb.
This light bulb (load) will have something we haven't talked about yet, 'resistance', which works pretty much exactly how the name sounds. It resists current flow. So if we put it in the path between a high voltage and a lower voltage, current will follow that path seeking balance, but only at the rate this resistance allows. The higher the resistance, the slower this movement. The higher the voltage difference between the source and ground, the faster this movement. And this movement of energy... those are 'amps'... which is a term used to describe how much energy moves from one point to another over a unit period of time. This is what ohms law is all about.
So to wrap things up, let's say our battery starts at 12.8V. We've chosen a 30A charger because 30 is as good a number as any other, and it's putting out 13.4V. (30A means it will allow up to 30A worth of current to flow out of it before it says 'no mas!'. Note this is completely different than 'pushing' 30A of current. An important conceptual distinction). The higher of the two voltages between the battery and the charger at this point in time is the charger, so between those two components, current flow will go from charger to battery (until they equal out). But what about the load? Well, let's say the load pulls 10 amps @ 13.4V, which is the higher of the voltage sources in our example. The charger can handle 30, so it's not maxed out yet, so in this case, current will flow from the charger to both the load, and the battery, at the same time. Bump the load up to 20A, that doesn't change... it's still within the capacity of the charger to provide. The battery will charge slower, as there's less total energy output by the charger that's free to do so, but it will charge. Now let's bump the load up to 30A. We're now at the capacity of the charger, so pretty much everything it's got is going into powering the load. So the battery just sits at 12.8V. No energy is flowing out of it, but none into it either. The difference between the voltage of the charger and the 'end' of the load (aka ground) is much greater than the difference between the charger and battery. Energy wants to balance itself out. The path through that load is, in this case, the best path to do so.
Now let's bump that load up to 50A. 30A was all our charger had, and all that current is now flowing though the load due to that difference in voltage potential. The battery is also exposed to that difference in potential, being at 12.8V relative to ground, so now current flow from it through the load at the same time. Now it's discharging.
In an actual system, you might have multiple batteries, multiple charging sources (DC-DC charger, solar panels via charge controllers, charging unit of inverter, etc), and multiple loads, all connected together in parallel. It seems complicated on the surface, but no matter how much 'stuff' there is, the energy flow still all works the same as described above.
I really hope this helps rather than confounds. I've rewritten this like 5 times trying to make it understandable, but it's kind of hard for me to explain. Just doing simple problems with ohms law really helps develop a more intuitive understanding of the dynamics at play. Long story short though, once you 'get it', you'll see it's not really as hard to get as you thought.
Edit: I guess a 50A light bulb was a stupid example, lol. Some like it bright lol!
