Solis Flexcore ID Battery Control Box

Every FlexCore-ID battery cluster is run from one FlexCore-ID-CB250A high-voltage control box. Rated 1000 V and 250 A, it joins the series string of packs to the inverter through its own breakers and contactors, and houses the battery management and a cloud gateway.

The box weighs 50 kg and matches the 532 mm width of a FlexCore-ID pack, so it stacks as the top layer of a column. Solis lists one with every system size from 60 kWh to 261 kWh.

The CB250A in figures

What the control box does

The packs of a cluster connect end to end, and the string's two ends terminate on the box's B+ and B- terminals. Facing the inverter it has two pairs of PCS terminals, P1 and P2, and a dedicated CAN port, JP6. A cluster breaker isolates the string, while two further breakers feed the box's DC/DC and AC/DC power supplies.

It also sends 24 V down the stack for the management unit and fans in each pack, carries CAN through the daisy-chained pack cables and assigns each pack its address. A green lamp shows the high-voltage bus is energised; a red one signals an alarm.

Monitoring, data and remote access

A gateway built into the box saves a CSV record of BMS data every 5 seconds and holds no less than 365 days of history, exportable through its web interface. It reports to Solis's Ginlong Cloud, pushing alarms as they occur and cluster and cell data once a minute by default.

For its uplink the gateway can use a wired network, Wi-Fi in station mode, or 4G, and the 4G route accepts a 15 × 12 mm Micro SIM only. Out of the box its Wi-Fi runs as an access point, so the commissioning engineer can open the local web pages from a phone. Gateway and BMS firmware can be upgraded remotely.

One box per cluster, and running clusters in parallel

The box count always equals the cluster count. With several clusters, the boxes are daisy-chained on the DC side, P2 of one to P1 of the next, while the first box's P1 and the last box's P2 go to the inverter's BAT1 and BAT2 inputs. Each box's JP4 port links to the next for parallel CAN and cluster addressing.

Start-up follows the same chain. The box holding the inverter communication powers up first, the rest follow in communication order, and the cluster quantity is entered in the inverter app before the cluster breakers close.

Siting and wiring the box

Sitting at the top of a column, the box shares the cluster's conditions: indoors, IP20, in a fireproof room with its own fire alarm and extinguishing equipment. Its manual switch goes to off before any pack is installed.

The DC leads to the inverter are made up on site, 25 mm² for clusters of 3–9 packs and 35 mm² for 10–13. For the inverter CAN link Solis recommends 0.35 mm² cable, no longer than 18 m. With the S6-EH3P125K10-NV-YD-H inverter, one phase of its backup output also feeds the box's AC220 input on JP5.

In the box

Order alongside

• Solis FlexCore-ID 20 kWh stackable battery

  The 20.09 kWh, 64 V LiFePO4 pack this box manages. Each cluster takes 3 to 13 of them in series beneath the box.

• Solis FlexCore-ID accessory kit for 3–4 batteries

  For a cluster in one column, with the 190 mm lead from the box to the first pack.

• Solis FlexCore-ID accessory kit for 5–9 batteries

  For five to nine packs over two columns, with the lower jumper leads that join the columns.

• Solis FlexCore-ID accessory kit for 10–13 batteries

  For ten to thirteen packs over three columns, with both upper and lower jumpers between them.