Growatt SPH vs SPA: Hybrid or AC-Coupled Retrofit for Home Storage?
Growatt's three-phase home-storage lineup answers two different questions with two machines built on the same 505×453×198mm, 30kg platform. The SPH 4000-10000TL3 BH-UP is a DC-coupled hybrid: solar strings and a battery connect to one box, which manages generation, storage and grid in a single conversion chain. The SPA 4000-10000TL3 BH-UP is the same battery and grid stage with the PV input deleted — an AC-coupled unit designed to bolt storage onto a solar system that already exists. If you are designing from scratch, the SPH is the default; if panels and a working string inverter are already on the roof, the SPA exists precisely so you do not have to rip them out. This comparison uses the 10000W flagship of each series.
One Platform, Two Roles
Both units deliver 10000W nominal AC on a 3W+N+PE three-phase connection at 230/400V, both manage batteries from 100V to 550V at up to 25A and 10000W continuous, and both accept lithium or lead-acid chemistry. The SPH adds the full solar front end: two MPP trackers rated for 7500W of recommended PV each, 1000V maximum DC voltage, 13.5A per tracker. The SPA has no PV terminals at all — its 'generation' input is the AC output of whatever solar inverter the site already runs. Everything else, from the LCD+LED display to RS485/CAN/USB interfaces, is common.
Specification Table
| Spec | SPH 10000TL3 BH-UP | SPA 10000TL3 BH-UP |
|---|---|---|
| Role | DC-coupled hybrid | AC-coupled retrofit |
| PV input | 2 MPPTs, 7500W×2 rec., 1000V max | None |
| AC nominal power | 10000W | 10000W |
| Grid connection | 3W+N+PE | 3W+N+PE |
| Battery voltage range | 100-550V | 100-550V |
| Max. charge/discharge current | 25A | 25A |
| Charge/discharge power | 10000W | 10000W |
| Battery type | Lithium / lead-acid | Lithium / lead-acid |
| Max. efficiency | 98.2% | 98.2% |
| Dimensions (W/H/D) | 505/453/198mm | 505×453×198mm |
| Weight | 30kg | 30kg |
| Protection degree | IP65 | IP65 |
| Warranty | 5 years | 5 years / 10 optional |
Operating range for both: -25°C to +60°C, night-time consumption under 13W, transformerless topology with natural cooling.
DC-Coupled vs AC-Coupled: Where the Energy Goes
In the SPH, solar DC can charge the battery through the inverter's internal bus — panel to pack without a round trip through AC. In an SPA system, solar energy is first converted to AC by the existing string inverter, then rectified back to DC by the SPA to charge the battery, then inverted to AC again on discharge. Each conversion has a cost, so a DC-coupled SPH system stores solar surplus slightly more efficiently end-to-end. The SPA's Euro-efficiency figures on the battery path (97.5% European efficiency on the AC stage) keep the penalty modest, but physics favours the hybrid when storage cycling is heavy.
Retrofit Reality: Why the SPA Exists
Millions of grid-tie string inverters are already on roofs worldwide, many only a few years into a 10-20 year service life. Replacing a healthy inverter to gain storage wastes working hardware and installer hours. The SPA drops in beside the existing system: it meters flows, charges the battery from surplus AC, and discharges into the home's three-phase distribution when the sun is down. Nothing about the original PV system is rewired at the string level. For households on time-of-use tariffs or with unstable grids, this is the shortest path from 'solar only' to 'solar plus backup'.
Sizing and Battery Pairing
Both series span 4000W to 10000W in the BH-UP generation, so match the unit to the site's three-phase load profile rather than the array size alone. The shared 100-550V battery window covers high-voltage residential packs, and the 25A / 10000W charge-discharge stage means a full-size battery can absorb the inverter's entire rated output. At 10kW of continuous discharge capability, either unit can carry a large household's evening peak — the difference remains solely on the generation side.
Winner
SPH for new builds; SPA for adding storage to an existing PV system
Conclusion
The decision tree is short. Building a new three-phase solar-plus-storage system: SPH, because one box handles PV and battery with fewer conversions between panel and pack. Adding storage to a functioning PV installation of any brand's string inverter: SPA, because it couples on the AC side and leaves the existing system untouched. Both share the same battery window (100-550V, lithium or lead-acid), the same 25A / 10000W charge-discharge stage, the same 98.2% peak efficiency and the same IP65 outdoor chassis, so you sacrifice no storage capability by picking the retrofit route. One planning note: the SPA's datasheet lists an optional 10-year warranty over the standard 5, worth pricing in for retrofits expected to outlive the original PV inverter.