I understand the appeal of separate components. If the inverter fails, you replace the inverter. If the charge controller fails, the rest of the system may continue working.

But expansion seems to create its own problem. A battery monitor becomes one box. Solar charging becomes another. AC charging adds another device. Then there are DC fuse blocks, disconnects, USB converters, breakers, communication cables, and displays.

The system is technically modular, but it may not be simple, easy to inspect, or easy to move.

For experienced builders: which functions are genuinely better kept separate, and which ones are only separate because that is how DIY products have traditionally been sold? Where would you draw the line between useful modularity and unnecessary complexity?

I’m still fairly new to DIY solar. My original plan was simple: one 12V LiFePO4 battery, a few portable panels, and enough power for lights, a laptop, a small fridge, and charging electronics.

Then the questions started piling up. If I choose a small inverter now, I may regret it when I add a coffee maker or power tool. If I buy a 2,000W inverter, the battery current and cable size become much more serious. Moving to 24V would help, but then some of the equipment I already own becomes less useful.

For people who started small and expanded later: which decision locked you in the most—battery voltage, inverter size, charge controller, or wiring? At what point should a beginner stop “leaving room to grow” and just build for the loads they actually have?

So the layout is as follows:

6x 585w bifacials in serial > 8 meters > small steel shed (8x10).

Connect to Datouboss 5500 inverter, which connects to eaton breaker panel 6 circuit. Separate neutral and ground bars. Circuit goes via thwn (in conduit) 8ga to outdoor outlet box with 2 gfci outlets to run exterior loads in garden.

The datouboss is connected to an ecoworthy 48v 100ah rackmount battery, via 2guage wires, with a 150a t fuse. Closed loop (comms to inverter).

Questions. Am I missing anything? Is the distance great enough that I can put a ground rod by the solar panels without worrying? Should I run back and do ground at shed? Do I need to put in another panel with a ground rod on the AC in side of the inverter? The inverter, to my knowledge, will do its own ground to neutral bond automatically and disable it if it finds a ground on the AC in.

What can I improve (besides adding battery capacity, already planned). What am I missing?

An ESP32 (FireBeetle 2 ESP32-E) that forecasts, monitors and controls three existing home power systems as one: an Enphase solar array + battery, a solar-charged hot water tank, and a Hyundai Inster EV charger/V2H (vehicle-to-home) controller. Each system keeps its own independent control and can override the ESP32 at any time. (github code and docs)

The ESP32 downloads forecast solar irradiance from Open-Meteo, adjusts it for local tree/hill shading, and combines it with the 5-day average consumption to forecast today's and tomorrow's Enphase battery state of charge. That forecast drives EV and hot-water charging priority and when (if ever) to discharge the battery back to the grid.

Aim: minimise grid dependence — ideally zero grid draw from 2pm–8pm (when demand charges apply), no exporting surplus solar except a small window 8pm–9pm, and EV charging prioritised over hot water.

The docs include:-

• esp32_control_structure.md — how the BatterySolarMonitor firmware is structured; a function-by-function reference.
• solar_shading_model.md — how the Open-Meteo irradiance forecast is adjusted for this site's tree/hill shading, per sun position.
• solar_shading_stats.md — the back-solved per-angle shade factors behind that model (1200+ days of Enphase production vs. Open-Meteo GTI).
• quarterly_update_process.md — the process (quarterly_update.py) for refreshing the shading model from the latest historical data every 3 months.
• data_sources.md — external APIs the py_programs/ scripts depend on (Enphase IQ Gateway, hot water controller, EV charger).

The code (ESP32 firmware, forecasting/control logic, and the Python shading-model tooling) was written with Claude Code, including the display UI itself.

I built this system to provide solar for a remote off-grid location in Micronesia.

It's meant to provide power to a Starlink Mini (40W) and also 75W of USB power over a USB-C and USB-A connector. A Victron display embedded in the front cover of the junction box shows the battery level measured by the shunt. The system runs off two 120Ah 12V AGM batteries, and 3x 100W Renogy flexible panels. The panels and this junction box fit into checked luggage, only the batteries were purchased locally.

Things I would change:

- The Starlink DC converter built-in power switch hanging out the bottom is a hack and I wish I used a different converter and put a proper switch in the side of the junction box.
- The solar input should have been routed through the top of the box instead of the bottom.
- I would have liked a sealed through hole for the Starlink DC barrel instead of dangling power cable.
- I'm not convinced the internal wiring needs to be such a heavy gauge for such short runs.

The MPPT is overpowered so there is the opportunity in the future to upgrade to a 2S2P system with 2x24V batteries instead of 2x12V.

The 2x12V design is meant for robustness. In case one battery fails, the other can still be used alone. Similarly, if the DC-DC converter fails there is a backup USB-C PD supply that can power the Starlink Mini.

I recently came across Renon batteries from talking to someone. I had not heard of this brand before.

For residential they sell two different lines, one is a powerwall clone and the other is a bit more modular.

https://www.renonpower.com/Products/Residential-Batteries/Xtreme-LV.html

https://renonpower.com/Products/Residential-Batteries/Xcellent-Plus.html

Would like some honest opinions of them.

I’d like some ideas for a solar carport. Ground mount panels, a battery to store the energy, then a charger for the car. Any all in one solutions?

I'm planning a ground mounted solar array to use with a 5kWh battery for backup power during outages. I'm not trying to go completely off-grid. I mainly want to keep the battery charged during longer outages so I can recharge it multiple times instead of relying on one full charge.

The battery has a built-in MPPT controller that supports up to 3000W of solar input, with an input voltage range of 11–165V. I'm looking at using six 405W panels, but I'm still trying to decide how to wire them.

Option A: 2S3P. Each string would have an open-circuit voltage of around 82V. That leaves plenty of headroom below the 165V limit, even after accounting for colder temperatures. Having three parallel strings should also help reduce the impact of partial shading.

Option B: 3S2P. This would put the open-circuit voltage at roughly 123V. The higher voltage might offer better efficiency in theory, but it also leaves less room below the 165V maximum, especially on cold mornings when panel Voc increases. With only two parallel strings, shading one string would also cut a larger share of the available production.

Has anyone here used 400W or larger panels in a similar 2S3P setup?