Li-ion Storage EX - battery

What it is

The Solar MD Li-ion Storage EX is a lithium battery with its own battery management system built into the pack. It stores energy on a site, protects its own cells, and works out for itself how much charge and discharge current it will allow at any moment. It reports all of that over a CAN link: pack voltage, current, state of charge, remaining capacity, and every cell's voltage and temperature. myPower24 monitors it, logs its data and includes it in plant control, through the LoggerV.

This page covers the EX-Series, which is listed under My Devices as Li-ion Storage EX Series. A battery identifies itself by the serial number written into its BMS, and that serial is its identity everywhere on the platform. Batteries built before firmware 200 never had a serial written into those registers, so the LoggerV builds one for them out of the numeric BMS serial, in the form SMDBEX followed by digits. On an older site you will see both styles.

Wire several batteries onto one CAN bus and they form a cluster by themselves. One battery becomes the master and speaks for the group, the rest are slaves, and there is nothing to configure to make that happen.

How it connects

• CAN bus at 500 kbps. The rate is fixed. The battery does not autobaud, so the LoggerV port has to be at 500 kbps and nothing else will work. The battery announces itself: it starts broadcasting as soon as it has power and the LoggerV picks it up from the traffic. There is no scan to run and no address to set on the battery.

CAN is the only way this battery talks to the LoggerV. It has no Modbus or Ethernet link to the logger.

What plant control can do with it

• Energy storage. The LoggerV gathers every battery on the bus into one storage cluster and hands that cluster to plant control, which pairs it with the inverters and chargers wired to the same DC bus. Plant control reads the cluster's state of charge, its capacity, and the charge and discharge allowance the batteries are signalling, and it holds the converters to those figures: it will not push charge into a cluster that has pulled its charge allowance back, and it winds discharge down as the discharge allowance falls away.

Plant control never writes a setpoint into the battery. Cell safety, current limiting and the main relay stay the BMS's own decisions and the platform follows them.

Separately from plant control, a battery can drive a third-party inverter's BMS port over its own CAN link. That is covered under Battery communication.

What the platform records

Logged for every battery on the bus. The sampling period is set for the whole device, not per value.

• State of charge, %.
• Pack current, A.
• Remaining capacity, Ah.
• Pack voltage, V.
• Internal pack voltage, V. This is pack voltage with the BMS's own compensation applied.
• Charge allowance, as a percentage of the battery's rated charge current. 100 means no limit.
• Discharge allowance, as a percentage of the battery's rated discharge current.
• Charge for the day, Ah.
• Discharge for the day, Ah.
• Lowest cell voltage, V.
• Highest cell voltage, V.
• Which cell is lowest, a cell number from 1 to 16.
• Which cell is highest, a cell number from 1 to 16.
• Lowest cell temperature, °C.
• Highest cell temperature, °C.

None of these is restricted. Anyone who can open the battery can chart all of them.

The cluster is logged separately, under the cluster rather than under any one battery: its total current, its average voltage, its average state of charge, and its charge and discharge control levels in both percent and amps.

Wiring

Connection diagrams are generated by the platform's Add-Device wizard; see How to add a device in myPower24. Take the battery's CAN connection to a CAN port on the LoggerV. The LoggerV's two CAN ports are shown in the platform as CANBUS 1 and CANBUS 2. Where there is more than one battery, wire them all onto the same bus and they will cluster themselves.

The CAN connector pinout, and whether the bus needs a terminator, are in the Li-ion Storage EX manual. Check it before you make up a cable.

Setting it up

1. Connect the CAN cable per the generated diagram, to a LoggerV CAN port running at 500 kbps.
2. Add the device on the LoggerV, choosing Li-ion Storage EX Series on the CAN port you used; see How to add a device in myPower24. You can skip this step on CANBUS 1 of a brand-new logger only: a LoggerV that has never had a device configured on any interface, and that is not running in debug mode, binds the Li-ion Storage EX driver to its first CAN port once, by itself. Once anything at all has been added to that logger, the shortcut is gone, and CANBUS 2 is never pre-bound.
3. Power the batteries. Each one appears under My Devices within a few seconds of starting to broadcast.
4. If two independent battery banks share one site, give each its own Cluster ID so plant control keeps them apart: on each battery, Settings > Installer > Control, under Cluster Custom Coms Advanced settings CANBUS/RS485. It takes a value from 0 to 15 and every battery in a bank must carry the same one. A single bank needs no change.
5. You know it worked when the battery's Realtime Data tab shows Battery State as RELAY CLOSED and Pack Voltage, Current and SOC are moving.

Battery communication

A Li-ion Storage EX can drive a hybrid inverter's charging and discharging directly, over a second CAN link from the battery to the inverter's BMS port. Both ends have to be set to the same protocol, and neither end works on its own.

On the battery, go to Settings > Installer > Control, find Controlled Device Settings, and set Controlled Device: to match the inverter. Choose Sunsynk for a Deye or a Sunsynk inverter, because the two share one protocol and there is no separate Deye entry. The other options are NONE, AUTO CANBUS, SMA, Victron, Goodwe, SAJ, Growatt, EV_GEN_CHARGER, TBB and SOLIS.

On the inverter, set its battery type to lithium and its lithium battery protocol to the Solar MD code. For a Deye or Sunsynk single-phase hybrid that means Control Mode set to Lithium Battery and Lithium Battery Type set to 0; see Deye 1Ph LV - single-phase hybrid inverter for the inverter side in full.

On the device page

Four tabs: General Info, Realtime Data (which opens first), Cluster values and Settings.

General Info is the nameplate: battery serial, manufacturer, model, rated capacity and voltage, rated charge and discharge current, the charging and discharging temperature windows, and the manufacturing date. Below that, the cell chemistry, manufacturer, model and series count; then the BMS's own serial, hardware revision, firmware revision, bootloader revision and build date; then the cluster ID and the storage and bus names.

Realtime Data opens with an Actual Values card: Battery State, Pack Voltage, Current, Power, SOC, Capacity Ah, Energy, Remaining Charge Time and Pack Voltage Internal. Battery State is where you look first, and it reads in capitals, for example RELAY CLOSED, RELAY OPENED, RELAY CLOSED - ENERGY SAVING MODE, RELAY OPENED - FUSE BURNED or RELAY OFF - ERROR PENDING. Under it, a Deratings table gives the charge and discharge limits the BMS is currently applying, by capacity, by voltage, by temperature and at the tripping level. Further down are the protection-unit relay current, the average and settled currents, the MCU, shunt, cell and balancing temperatures, and the daily, monthly and total charge and discharge counters with a Refresh counters button.

Cluster values is the group view: Role in cluster (Master or Slave), Master Serial Number, Total Batteries in Cluster, DC Connected Batteries, Online Batteries, Offline Batteries, the cluster's rated capacity and rated charge and discharge current, then its live average capacity, capacity in Ah, total current, average voltage and cell difference, then a Limits table with the cluster's charge and discharge current and voltage limits. Interface Stat on the same card reads the CAN bus counters back off the battery, which is the quickest way to tell a live bus from a dead one.

Settings has two sub-tabs. Installer holds LED, Control, Control Dev Test, Rated Parameters and Firmware. Advanced holds Cluster Settings, Charge/Discharge Control, Balancing, Rated Parameters, Cell Measuring, Temperature Control, Voltage Limits, Protection Relay, INA Current measurement, Capacity Alignment and Usable Capacity.

A healthy link reads: the battery listed under My Devices, Battery State at RELAY CLOSED, Pack Voltage, Current and SOC all updating, and on Cluster values an Online Batteries count that matches the number of batteries you wired.

Maintenance

Firmware

Firmware is handled from Settings > Installer > Firmware. Press Show Firmware Data to open the firmware dialog. Inside it:

• Check for Online Update asks the LoggerV to look for newer battery firmware online.
• Copy Firmware <version> transfers the image to the battery. The battery keeps running normally while it transfers and you get a progress bar.
• Install Firmware <version> applies the transferred image.

Replacing a BMS board

When a replacement BMS board is put onto the bus, the LoggerV recognises it, hides it from the device list so it cannot be mistaken for a working battery, and opens a Replacement BMS Detected dialog with Cancel and Start Replacement Process. If you cancel it, the Replacement BMS Detected service alert stays on screen with a Click here to complete link that reopens it.

Start Replacement Process opens the BMS Replacement Wizard. Type the serial number of the BMS being replaced into Old BMS serial number and press Complete Replacement. The logger finds that BMS's most recent backup, writes its rated capacity, currents, voltages, cell settings, energy counters and serial number into the new board, and reboots it. The new board then rejoins the bus as the battery it replaced.

Two things have to be true first. The old BMS must be off the bus, and the replacement board must be on firmware 202 or newer; if a newer image is already staged on the board the logger applies it for you and you retry. The transfer is not reversible, and on a site with more than one battery model, restoring the wrong backup gives the new board the wrong rated current and capacity, which the wizard warns can cause overcurrent on the shunt, cables and terminators, blown fuses, cell imbalance and wrong readings.

The logger writes a parameter backup for each battery it can see about once a day, and keeps the last ten per battery, so a battery that has been on this logger before can be restored. One that has not, cannot.

Troubleshooting

The battery is not there

• A battery never appears after wiring it. Detection is automatic, so nothing was missed in the platform. Check the CAN wiring, that the bus is terminated, that the battery is powered, and that it is on the CAN port you configured. Interface Stat on Cluster values shows whether the bus is carrying anything.
• A battery that was working goes offline. CAN communication was lost. Check the cabling and that the battery still has power. The cluster raises "One or more batteries in the cluster are Offline." when this happens.

Cluster warnings

• "One or more batteries in the cluster are Offline.": a battery the cluster knows about has stopped answering. Find it and check its power and CAN link. If a battery has been permanently removed, clear the stale entry with Reset Cluster Known Devices under Settings > Installer > Control.
• "One or more batteries in the cluster are DC Disconnected.": a battery is communicating but its main relay is open, so it is not on the DC bus. Check that battery's Battery State for the reason.
• "More than one Master Battery in cluster found.": two batteries both believe they are master, which usually means the bus is split and the two halves cannot see each other. Check that every battery is wired onto the same CAN bus.
• "Cluster Fw difference.": the batteries in the cluster are not all on the same firmware. Bring them up to matching versions.

The inverter link

• "Controlled device coms fail." and "Master Battery to Controlled device msg timeout.": the battery is set to drive an inverter and cannot reach it. Check the CAN cable between the battery and the inverter's BMS port, and that Controlled Device matches the inverter and the inverter's own battery protocol matches back.

Battery faults

These come from the BMS itself and describe real hardware or cell conditions.

• "Cell voltage too low.", "Cell voltage too high.", "Charge current too high.", "Discharge current too high.", "Error Charge Current Critical High.", "Error Discharge Current Critical High.": the pack is being worked outside its limits. The BMS is already derating; check the plant's charge and discharge settings against the battery's ratings on General Info.
• "Error Temperature Critical Low.", "Error Temperature Critical HIGH.", "Temperature Limit, charging current too high.", "Temperature Limit, discharging current too high.": the pack is outside its temperature window. Check ventilation and ambient temperature.
• "Error Voltage Too LOW, Sleep Mode Active.", "Error Cell Voltage Critical Low. Shutdown Activated", "Error Critical High Voltage, Sleep Mode Active.", "Error Critical High Voltage, Sleep Mode Awake.": the pack has protected itself and opened its relay. It will not carry current until the condition clears. "Pending awake Low state." and "Pending awake High state." mean it is on its way back out of that state.
• "Protection Main Relay Coil Open.", "Protection Main Relay Fuse Burned.", "Protection Main Relay Overcurrent.": the main relay or its fuse has failed. The battery cannot connect to the DC bus. Contact support.
• "Open cell wire detected.", "External Temperature Shunt Sensor Faulty or not Connected.", "External Temperature Sensor Faulty or not Connected.", "Externel Temp Sensor is Faulty.": an internal sense wire or sensor is broken. Contact support.
• "Tilt X axis out of range.", "Tilt Y axis out of range.", "Tilt Z axis out of range.": the pack is not sitting the way it should. Check the mounting and that nothing has shifted or been knocked.
• "Override ON Active.", "Override OFF Active.", "Override On enabled.": somebody has forced the main relay from Settings > Installer > Control. Press Clear Override there to hand control back to the BMS. "Error Override Range Exceeded. Shutdown Activated" means an override held the relay past a cell limit and the BMS shut down to protect itself.
• "Bms locked in manufacturing phase.": the board has not been released by the factory. On a replacement board this is expected and the replacement wizard clears it; on any other board, contact support.
• Seven further messages start with "Internal fault," and name a memory, reference or cell-measuring failure. There is nothing to configure. Note the exact wording and contact support.

Replacing a BMS board

• "Can not transfer configuration while BMS online. Please follow steps or ask for support!": the BMS you named as the old one is still answering on the bus. Disconnect it, wait for it to go offline, then retry.
• "Can not find backup for BMS serial number: ... Please verify BMS serial number is typed correctly or check old BMS has been connected at least ones to this logger.": either the serial is mistyped, or that BMS has never been on this logger, so there is no backup to restore.
• "Internal fault. Replacement BMS firmware must be 201 or greater": the replacement board's firmware is too old to accept the transfer. The real threshold is 202 despite what the message says. Update the board first.
• "Internal fault. Replacement BMS is not connected" and "Internal fault. Can not find replacement bms with serial: BAT_IN_PROD": the logger cannot see the new board. Check its CAN connection and power.
• "Update in progress !" and "Write not allowed, Update In Progress!": a firmware transfer is running. Wait for it to finish, then retry.
• "Minimum firmware for field: ...": the setting you tried to change does not exist on that battery's firmware version. Update the battery, or leave the setting alone.

Who can do what

• Regular user (basic): opens the battery, reads everything on General Info, Realtime Data and Cluster values apart from the per-cell detail, and has the whole Installer settings sub-tab. Nothing on that sub-tab is gated, so a regular user can set the LED modes, the storage and bus names, the cluster ID, the bus settings for the inverter link, the Controlled Device protocol, Reset Cluster Known Devices, the main-relay override and the firmware buttons.
• Advanced user (advanced): adds the Advanced settings sub-tab in full, the per-cell voltage and temperature tables on Realtime Data and Cluster values, the measured capacity and state-of-health figures, System uptime, the Browse Backups list in the replacement wizard, and the wizard's Apply Battery Model tab.
• OEM (oem): nothing further. The oem tier gates nothing at all on this page.

A higher tier bypasses the lower gates. Two further permissions sit outside the three tiers. A firmware developer (fwDeveloper) can copy an image to every battery at once, reinstall a version a battery already has or has passed, and choose any available version instead of the next one up. Calibrating the cell-voltage offset needs a separate battery-calibration permission (bms_calibrator): the control appears for an advanced user, but the LoggerV refuses the write to anyone without it.

Two of the ungated controls are consequential and worth knowing about before handing a site over. Override ON and Override OFF, under Settings > Installer > Control, force the battery's main relay closed or open for a set number of seconds, which on a single-battery site takes the battery off the DC bus. And the firmware buttons switch the battery off for about a minute while an update applies. Both are available to any signed-in user who can open the battery page.

Tips and gotchas

• Every battery in one bank must carry the same Cluster ID. A battery on a different ID forms a cluster of its own and plant control treats it as a separate bank.
• Firmware differences inside a cluster are worth clearing before you leave site. They raise "Cluster Fw difference." and the batteries do not all behave the same way at their limits.
• A battery whose BMS has been swapped keeps the old battery's identity, not the new board's. That is the point of the replacement flow, and it is why the logger's daily parameter backups matter: without one, there is nothing to restore from.