Checked as a bank of 2 packs, which is the smallest number that accepts this inverter’s 85 amp charge current. Fewer packs still run the system, with the charge rate capped in inverter settings.
Full specifications: OutBack VFXR3648A and Pylontech US3000C.
The four checks
Voltage window: Overlapping window 44.5 to 54 V
The inverter operates from 40 to 64 volts and the battery cuts off outside 44.5 to 54 volts. Both stay inside 44.5 to 54 volts, which covers a normal LiFePO4 charge and discharge cycle with margin at both ends.
Charge current: 85 A into a 148 A limit
The inverter tops out at 85 amps and the battery accepts 148 amps, so a default install cannot overrun the pack. Adding batteries in parallel raises the accepted current further.
Surge rating: 200 A surge for 15 s against a 150 A peak
The inverter surges to 7200 watts, about 150 amps at 48 volts, and the battery is rated for 200 amps for 15 s. A compressor or well pump start has room inside that rating. Compare the durations as well as the amps, because the ratings are only equivalent if the pack can hold its figure as long as the inverter holds its own.
Closed-loop communication: No shared protocol
The inverter speaks Modbus and the battery speaks CAN, RS485. There is no common protocol between them, so closed-loop operation is off the table regardless of cabling.
What this means when you install it
Set the inverter charge current to 85 amps or less. That is the inverter maximum, which this bank can absorb. Protect the battery run with a 100 amp Class T fuse and 2 AWG cable wired to a busbar rather than daisy chained, so all 2 packs share current evenly.
The inverter speaks Modbus and the battery speaks CAN, RS485. There is no common protocol between them, so closed-loop operation is off the table regardless of cabling.
Figures side by side
| Field | OutBack VFXR3648A | Pylontech US3000C |
|---|---|---|
| Voltage window | 40 to 64 V | 44.5 to 54.0 V |
| Charge current | 85 A delivered | 148 A accepted (2 packs) |
| Peak draw | 7,200 W surge | 200 A surge (2 packs) |
| Usable capacity | n/a | 7.1 kWh (2 packs) |
| Comms | Modbus | CAN, RS485 |
Manufacturer documents
Manufacturer documents: OutBack Power documentation. Figures here should be read against the revision that covers your serial number, because manufacturers revise specifications without changing the model name.
Manufacturer documents: Pylontech product documentation. Figures here should be read against the revision that covers your serial number, because manufacturers revise specifications without changing the model name.
Both units, current pricing
Prices on these move week to week, and the battery is usually the line item worth watching.
OutBack VFXR3648A on AmazonPylontech US3000C on AmazonComms cableAffiliate links. As an Amazon Associate this site earns from qualifying purchases, at no extra cost to you. Prices and stock change often, and a listing appearing here is not a statement that the pairing above is approved.
Other pairings for the Pylontech US3000C
EG4 6000XP with Pylontech US3000C
Specs conflict on at least one field.
EG4 18KPV with Pylontech US3000C
Partial match, some fields unverified.
EG4 FlexBoss21 with Pylontech US3000C
Partial match, some fields unverified.
Sol-Ark 12K with Pylontech US3000C
Partial match, some fields unverified.
Questions people actually ask
Will the OutBack VFXR3648A work with the Pylontech US3000C?
Specs conflict on at least one field. Checked as a bank of 2 packs, which is the smallest number that accepts this inverter’s 85 amp charge current. Fewer packs still run the system, with the charge rate capped in inverter settings. The four checks below show which field produced that result.
What does this pairing cost to wire up?
Beyond the two units, a 100 amp Class T fuse and holder, 2 AWG battery cable cut to matched lengths, and a busbar if you are running 2 packs. A comms cable if you intend to attempt closed loop, and the pinout is rarely the same between brands.
Where does this pairing go wrong in practice?
The inverter speaks Modbus and the battery speaks CAN, RS485. There is no common protocol between them, so closed-loop operation is off the table regardless of cabling.
What charge current should I set?
The inverter tops out at 85 amps and the battery accepts 148 amps, so a default install cannot overrun the pack. Adding batteries in parallel raises the accepted current further.