So your existing power setup isn't meeting needs and you want to change it. Maybe your daily power requirements have increased, you bought a pre-built van, or your use case has changed.

• the first step to fixing a problem is to understand the problem
• human nature leads us to want simple solutions to complex problems
• marketers and influencers have vested interests in convincing us that simple solutions exist: “What you need is a [insert product here]”
• successful upgrades are more about understanding needs and what interventions are practical for your use case

about these summaries

There is a saying that

defining the real problem is is 90% of the solution

… and that applies here. I understand why we humans don't want to spend time/effort figuring out the probem. It's not fun and we don't get to buy stuff yet.

There are two main areas where the problem can reside, or it can be in both.

This is listed first because reducing demand is free¹⁾ and trivial to test. It's like the old joke:

Patient - “it hurts when I do this (sticks finger in eye)”
Doctor - “So stop doing that.”

Some loads are mandatory and we can't “stop doing that”. Your insulin might require a powered fridge at all time. But many high-current loads newbies try to run (and crash their power setup) are easy and cheap using traditional methods. Electric water heating vs propane water heater (or kettle over a stove), for example.

Sometimes just changing when the load runs can eliminate/reduce required upgrades. Consider a system with limited Ah capacity that sags under load and trips the inverter's low voltage protection. Running that same load when the solar or alternator are making power can reduce the sage, reducing or eliminating the problem.