The Ecoflow Delta 2 Max has 2 solar inputs, so I have 2 strings of panels connected. Each has a pair of 200w panels mounted on a fence facing south. Towards the end of the day these don’t produce much. so I sometimes will swap out one of the strings to a portable 450w panel that I can face west and get a couple more hours of sun. I have very limited space that gets sun, so I can’t have a large array.

I would like to permanent mount a pair of 250w panels facing west and have a way to easily switch between it and one of the other strings without have to manually disconnect the cables. (I struggle with disconnecting mc4 connections, even with the tool). Does a switch that can do this exist?

Hey everyone, looking for a sanity check on a pure AC battery load-shifting setup (no solar panels).

I'm in California dealing with wild TOU rates—around **$0.82/kWh on-peak vs $0.13 super off-peak**. The plan is simple: charge a ~5kWh battery from the wall overnight, then backfeed through a microinverter from 4–9 PM to reduce my house's base load.

EcoFlow (STREAM / Delta Pro) is the obvious plug-and-play route, but getting to 5kWh+ with expansion batteries is easily **$4,000–$4,500+**.

Building it modular looks like it comes in around **~$2,200**:

* **Battery:** 48V 100Ah (5.12 kWh) EG4 LiFePO4 server rack battery

* **Inverter:** Hoymiles microinverter (UL 3700)

* **Meter/Control:** Shelly Pro 3EM + OpenDTU-OnBattery for dynamic zero-export

* **Charging:** 48V AC-DC smart charger on a scheduled plug + 2P DC breaker & pre-charge resistor

For anyone running a similar battery-fed microinverter setup:

1. **Hoymiles on constant DC:** How does the inverter hold up long-term being fed constant 48V DC from a battery instead of PV? Any overheating or MPPT hunting quirks?

2. **Zero-export latency:** How fast is the Shelly -> OpenDTU loop in practice? Does it throttle back quickly enough when heavy loads drop so you don't accidentally export to the utility?

3. **CA / Safety practicalities:** With CA moving toward UL 3700 plug-in rules, any major red flags running a certified microinverter + server rack battery on a dedicated circuit vs waiting for overpriced all-in-one consumer units?

Appreciate any feedback or tear-downs of this plan before I start ordering hardware.

Hello, everyone. I’m new to solar and new to Reddit. So, apologies if this is a basic question that’s been asked a thousand times before. I just hooked three 100w, 18v panels up for the first time to a BLUETTI Elite 300 power station. It has a 1200w 60v 22a MPPT. When I hooked the panels up individually, the voltages were 18.0, 17.8, and 17.4. When I connected them in series, they were 65.7. I’m at a loss to figure out why the voltage spiked so high when they were all connected. I then connected two and got 36.2, so that checks out. It’s only when I connect three together that I magically gain about 12v. I used a multimeter and got the same voltage reading as I got from the MPPT, so I’ve eliminated a faulty MPPT as the cause.

So, is this what I get for buying no-name panels off eBay? Is there a fix other than returning the panels and buying new ones. If so, what are your recommendations for reputable brands? I’m sure that thread is already on here, so I‘ll do some digging, but if anyone has any recommendations, I’d appreciate them.

Thanks for your help!

I’ve built a tiny house in Texas. It’s hot. I added another 20x20 building that came with an inefficient minisplit. To keep all cool uses ~2-2.8 kWh running a/c. I’ve got 39 kWh of storage. 12,420w of panels. Fiancé moved in with an EV and it smokes my storage charging at night.

I need more storage. I’ve got 5400w more of panels to install. Waiting for Marketplace deals for more. I’m just struggling for storage. Her commute uses 35 kW 3 days a week. Adding an additional 40 would be ideal.

What’s the best affordable storage solution?

Edit as best I can:
Sorry for my lack of correct kw vs kWh knowledge. I’m still learning. Tiny house started as a 12’ x 36’ 13’ tall shed built with a 10’x 20’ loft. It has the Della hvac with 3 air handlers. Typically only run 1-2 at a time. Added a 20’ x 20’ building that came with the inefficient Royal Bear hvac.
Both buildings have floor to ceiling insulation with finished out walls.
Grid tie-in is financially impossible due of location and cost to run the distance. Coop quoted $50k not including removing 30 large oak trees.

Here’s my current setup. Panels are installed on a 150’ x 40’ shop roof.
Panels
( qty 36) SPR-X21-345-COM Sunpower 345 Watt Maxeon Cells Helix Frame
**Not installed yet** (qty 15) Silfab SIL-360NX

Inverter
(2x) Schneider XW Pro 6848 inverter

Solar charger
(2x) Victron SmartSolar MPPT 250/100-Tr VE.Can

Batteries
(6x) SunPower M0020 batteries 6.5Kwh

Generator charger
EG4 Chargeverter – GC | 48V 100A Battery Charger 5120W Output | 240/120V Input

HVAC units
Della 27K BTU ODU Tri 3 Zone 9K
9K 9K
Royal Bear 12k BTU. Model FV-RB-EXMSCH-12K110-1

(2) full size Refrigerators

You might be curious or be able to learn from my experience…

I failed to recognize matching output voltage of the solar panels (327W) with the input voltage of the inverter. :(

I did not realize the voltage output from the panel will get higher as the weather gets colder. The coldest day around here is -15'C so that would push Voc up to 72V.

https://preview.redd.it/06j1n0xlbsjh1.png?width=364&format=png&auto=webp&s=4516d71006674c6f6c7468c7ae1ff97d6847abc2

And I didn't realize the voltage can not be regulated by shading some of the panel. Now that I'm aware of this problem it is obvious that is what this chart is showing. The voltage output stays high even at very low intensity.

From PV Spec Sheet Sunpower E20/327

I have thought of 2 solutions since I already own the panels and the EcoFlow Stream (max input 60v).

1. Buy a DC to DC stabilizer or buck boost converter and wire it into the junction of the panels ($30 per panel and effort). The stabilizer is 6A and would drop the input into the inverter to a safe 48V. The rated current (Imp) output of the panel is 5.98 amps. 6A x 48V = 288 watts

Described as waterproof

2. Solder a piece of wire to drop the voltage of 65 by 1/3 to 43V. Even in the winter time the panels will output less than 60V into the inverter. The yellow would be a solid piece of wire. How many amps would the PV output? How many watts?

PV junction box

Will either of these things work? Thoughts?

I’m planning a ground-mounted solar build at my rural property and could use some advice on the layout and equipment configuration.

Because of site layout and space, all the main equipment (ground mount array, hybrid inverter, future battery bank, and generator) will be located at an outbuilding about 300 feet away from the main house.

Property & Infrastructure Details:

• Main House: Location of the utility meter and main service panel. The basement has no room for inverters or battery banks.
• Outbuilding & Feeder: Located 300 feet from the house, connected via an existing 100A underground feeder. Running new cable or trenching between the house and outbuilding is not an option.
• 12kW Generator: Located at the outbuilding. It currently runs through an older manual disconnect setup to backfeed and power the entire property during blackouts. Voltage drop over the 300ft feeder has never been an issue under full load.

The Build Plan:

• Phase 1: Ground-mount solar array with a hybrid inverter at the outbuilding. Grid-tied to offset house energy use by backfeeding through the existing 100A feeder line. No batteries initially.
• Phase 2: Add a battery bank at the outbuilding for blackout backup.
• Generator Integration: Integrate the existing 12kW generator directly into the hybrid system so it can charge the batteries and supplement solar during extended power outages.

Questions:

1. Islanding & Grid Isolation: When the power goes out, I need to isolate the house from the grid so the inverter can island the outbuilding and feed backup power to the house over the 300ft line. If the hybrid inverter and batteries sit at the outbuilding, what is the best way to handle grid isolation at the house service entrance?
2. CT Sensors / Energy Monitoring Across 300 Feet: Most hybrid inverters use CT sensors at the main service panel to monitor grid power flow and manage zero-export or battery usage. Without laying new wires, what options exist for sending CT data or Modbus communications 300 feet back to the outbuilding (e.g., wireless bridges, Modbus over powerline, etc.)?
3. Hybrid Inverter & Generator Setup: For those running hybrid inverters (like a Sol-Ark, EG4, or similar) with a dedicated generator port, how well does the inverter handle blending solar, battery, and a 12kW generator when feeding a remote main panel over a long subpanel line?

Appreciate any recommendations, potential pitfalls, or equipment suggestions from folks with similar setups!

I’m putting together a DIY 12V power station and I want to make sure I’m sizing the cables, fuses, and disconnect switch correctly before I buy everything.

What we purchased:

• Batteries: 3 × DC HOUSE 12V 150Ah LiFePO4 Batteries with Bluetooth, SOC Indicators & Low-Temperature Protection
• Battery charger: 1 × DC HOUSE 12V 10A Smart LiFePO4 Battery Charger for LiFePO4 & Lead-Acid
• Inverter: 1 × Renogy P2 700W Pure Sine Wave Inverter, 12V DC to 120V AC

What we’re planning for the setup:

• All three 12V 150Ah batteries connected together in parallel for a 12V 450Ah battery bank
• Positive and negative busbars
• Fuses between the batteries and equipment
• A battery disconnect/master switch so we can easily shut the whole DIY power station off
• Solar later, but for now we’ll recharge with the battery charger

We were originally thinking about using 2 AWG cable for most of the high-current connections, but the more I’ve been reading, the more I realize that the correct wire size depends on both the amperage and the length of each cable run.

I’ve also read that on some very short cable runs, something like under 7 inches, a separate fuse may not always be required, but I’m not sure if I’m understanding that correctly. I really just want to make sure we buy everything we need and build this safely.

My questions are:

1. What size cable should I use from each battery to the busbars?
2. What size cable should I use from the busbars to the 700W inverter?
3. Is 2 AWG overkill, appropriate, or not large enough for these connections?
4. What size main fuse should be installed between the battery bank and the rest of the system?
5. What size fuse does the Renogy P2 700W inverter need? I cannot find this information on Renogy’s website.
6. Where should the fuse for the Renogy 700W inverter be installed? At the busbar, near the inverter, or somewhere else?
7. Should every positive cable coming off the busbar be individually fused?
8. Can you add a fuse directly to a busbar, or is there even a need to? Would it be better to buy a fused busbar instead of a regular busbar and separate fuse holders?
9. Is it true that very short cable runs sometimes don’t require a separate fuse, or should I still fuse them?
10. Is ANL appropriate for these fuses, or should I be using something like MRBF instead?
11. How close to each battery should its fuse be?
12. Since we are connecting all three 12V 150Ah batteries together in parallel, should each battery have its own fuse before connecting to the positive busbar? If so, what size fuse and cable should be used for each battery?
13. What gauge cable should we use for the different lengths and parts of the system?
14. We want a master on/off switch on the DIY power station so it’s easy to completely shut it down. Where in the system should the disconnect switch go, and what amperage rating/type of switch should we use for this battery bank?
15. Should the master disconnect switch shut off everything, including the inverter and anything else connected to the busbars?
16. Is there anything else I’m forgetting that we should include to make this DIY power station safe?

I’m not trying to size everything as cheaply or minimally as possible. I’d rather go a little oversized on the wiring if that gives us some headroom and helps reduce voltage drop and heat.

This is my first time building something like this, so I’m trying to double-check everything before ordering the rest of the parts.

Edit 1: I should have added that this setup is going to be used for a continuous off-grid livestream. It will be running Axis cameras, a network switch, an outdoor ONT, and a router, which should come out to around 100 watts of continuous power draw. The inverter itself uses about another 10 watts, so the total continuous draw should be around 110 watts.

One of the main reasons we went with multiple 12V batteries is because my dad can’t lift a 100-pound battery, so we needed something that would be easier for him to handle while still giving us enough capacity for the livestream setup.

What is the biggest small footprint (renogy 100 watt size) solar panel available? My van needs an upgrade in the same space. I’m looking at HQST 200 bifacial but wondering if there’s anything that size in a 300watt.