Both brands make capable 48V split-phase inverters for North American homes. The real difference is the company behind the box. EG4 is a young US brand that sells hardware built by other companies' factories. Growatt is a global manufacturer that designs and builds its own inverters and batteries.
If you're planning an off-grid cabin, a whole-home backup system or a hybrid setup that sells power back to the grid, this guide compares the two brands as companies: who they are, what they make, how they back their products, and which one fits your project.
Who they are
EG4 is a 2020-era US brand rooted in Texas DIY solar. Growatt is a Shenzhen manufacturer whose roots go back to 2010, and it now sells in more than 190 countries.
EG4 Electronics
- Origin: Launched in 2020 by James Showalter, who installed his own off-grid system in 2013. The name stands for "energy generation for everyone" (Solar Power World).
- Base: Sulphur Springs, Texas. The Showalter brothers first built Signature Solar, a distributor, then created the EG4 brand around their own server rack batteries (EG4).
- Manufacturing: EG4 doesn't build its own core hardware. Its inverters are made by LuxpowerTek, a Chinese OEM, and its batteries come from Chinese suppliers. EG4 handles final assembly, repair and support at a 310,000 sq ft facility in Commerce, Texas, and it acquired US off-grid brand OutBack Power (Solar Power World).
- Reputation: Installers praise its pricing and easy RMAs. Some also note that early-generation products lacked UL listings and had quality issues that later models fixed.
Growatt
- Origin: Founded in Shenzhen, China. Its predecessor company was established in May 2010, and the Growatt brand dates to 2011 (Growatt press release).
- Scale: Operations in more than 190 countries and regions, 63 sales and service locations across 30 markets, and about 4.2 million end users on its monitoring platform. Nearly 1,000 R&D staff work across three R&D centres.
- Rankings: S&P Global named Growatt the world's No. 1 residential PV inverter supplier for 2024, and top 3 in hybrid inverters (press release). It is also an S&P Global Tier 1 PV inverter supplier for 2026, one of 12 worldwide.
- Manufacturing: Growatt designs and manufactures its own inverters and battery systems in its own factories. These include a 200,000 m² manufacturing base in Huizhou, China (PV Tech), and a plant in Haiphong, Vietnam, that builds inverters and storage batteries (PV Tech).
Brand vs. manufacturer: the biggest difference
EG4 doesn't manufacture its own inverters or batteries. Growatt does. That one fact shapes quality control, firmware, spare parts and how long your system will be supported.
| EG4 | Growatt | |
|---|---|---|
| Inverters | Built by LuxpowerTek, a separate Chinese manufacturer, and sold under the EG4 name | Designed and built by Growatt |
| Batteries | Sourced from Chinese battery suppliers | Designed and built by Growatt (ALP, APX lines) |
| Factories owned | Texas facility for final assembly, repair and support | 200,000 m² base in Huizhou, China; inverter and battery plant in Haiphong, Vietnam |
| Who controls design and firmware | Shared with the OEM partner | Growatt's own ~1,000-person R&D team |
Why it matters: when a manufacturer builds its own products, one company owns every fix, from a firmware bug to a failed board in year eight. With a rebranded product, the seller depends on a supplier relationship that can change. Ask any brand which factory builds the unit you're buying.
Where EG4 shines
EG4 earned its following with aggressive pricing and a strong DIY community. Credit where it's due:
- Price-focused and fast-moving. EG4 built its following on aggressive pricing and quick product launches for the DIY market.
- US presence. EG4 runs a 310,000 sq ft Texas facility for assembly, repair and support, and offers US-based phone support. It also owns OutBack Power and has a US battery cell supply deal with LG Energy Solution.
- Active community. EG4 is widely discussed on DIY solar forums, so owners can find plenty of peer advice online.
The big trade-off: EG4 is a brand, not a manufacturer. Its inverters are built by LuxpowerTek and its batteries by Chinese suppliers, so quality control and long-term parts supply depend on factories EG4 doesn't own. Installers also remember early products that lacked UL listings.
Where Growatt shines, and why we build on it
Growatt's edge is staying power. When your inverter needs a firmware update or a warranty claim in year eight, the size and track record of the manufacturer matter more than the sticker price.
- Proven at global scale. Growatt has 15+ years in business, millions of connected systems, and S&P Global's No. 1 residential inverter ranking for 2024.
- It builds what it sells. Growatt designs and manufactures its own inverters and battery systems. The company on the label controls the design, the production line and the firmware, and it stands behind all three.
- Deep in-house R&D. Nearly 1,000 R&D staff across three R&D centres develop Growatt's hardware and firmware.
- One company from cabin to commercial. Growatt serves homes, farms and commercial sites in more than 190 countries, with 63 sales and service locations.
That's why every ROCKSOLAR off-grid and hybrid kit is built on Growatt inverters. We pair them with Growatt or GSL LiFePO4 batteries and matched solar panels, and pre-configure the whole system so it works on day one.
Who's more likely to be around to honour your warranty?
A 10-year warranty is only as good as the company behind it in year 10. No one can predict the future, but the long-term signals favour Growatt.
| Signal | EG4 | Growatt |
|---|---|---|
| Time in business | Brand launched in 2020 (~6 years) | Predecessor company founded May 2010 (~16 years) |
| Where sales come from | Mainly the US DIY and installer market | 190+ countries, residential plus commercial and industrial |
| Independent financial screening | Not on S&P Global's 2026 Tier 1 inverter list | One of 12 Tier 1 inverter suppliers for 2026, screened for scale, financial performance and credit risk (pv Europe) |
| Who makes the product it warrants | A partner OEM (LuxpowerTek) | Growatt's own factories |
| Financial disclosure | Private company, no public financials | Has prepared a Hong Kong listing document (HKEX), which brings public reporting |
Why this matters for your warranty:
- The warranty is only as strong as the warrantor. EG4's 12000XP warranty is issued by EG4 Electronics LLC, and it doesn't say what happens if EG4 stops trading (EG4 warranty). LuxpowerTek, the company that builds the inverter, isn't a party to it.
- Owning the factory means owning the fix. Growatt makes its own inverters and batteries, so it controls replacement boards, spare units and firmware for the products it warrants.
- Diversified companies weather downturns. Solar demand moves with tariffs, interest rates and incentives. A company selling worldwide across home and commercial markets doesn't depend on one region's market cycle.
To be fair to EG4: it has invested heavily in US operations, including a Texas facility, the OutBack Power acquisition and a battery cell supply deal with LG Energy Solution through 2030. Those are signs of a company planning to stay. It just hasn't been tested over a full warranty cycle yet.
Which should you choose?
For most homeowners, Growatt is the safer choice. You're buying from the company that designs and builds the hardware, with 15+ years of history and independent financial screening behind its warranty.
EG4 can suit hands-on DIYers who value its pricing and community, and who are comfortable with a younger brand that relies on partner factories.
FAQ
Is EG4 made in the USA?
Not the core hardware. EG4 doesn't manufacture its own inverters or batteries: its inverters are built by LuxpowerTek in China, and its batteries come from Chinese suppliers. EG4 does final assembly, repair and support in Commerce, Texas.
Is Growatt a reliable brand?
Growatt has been making inverters since 2011. S&P Global ranked it the world's No. 1 residential PV inverter supplier for 2024 and lists it as a Tier 1 inverter supplier for 2026.
Ready to go solar?
Browse ROCKSOLAR's Growatt-powered off-grid and hybrid kits, from small cabins to large homes and farms. Each kit comes with Growatt or GSL LiFePO4 storage, and our team will help you size it.