Batteries

Each node contain two batteries that provide sufficient power to the node canister to allow an orderly shutdown in the event of a loss of power from the electrical utility. If the power to a node fails, it can write the configuration state and cache state to the internal drive using the power provided by the battery.

The battery is maintained in a charged state by the battery subsystem. In this state, the battery can save critical data and state information in two back-to-back power failures. This means that the node can start immediately after the first power failure without waiting to recharge. After rebooting, if the battery does not have enough charge for a node to save its internal state, the node remains in service until the battery is charged sufficiently. Although the node can run with a single battery, two batteries are needed to achieve redundancy. The node that runs on one battery is considered degraded and a node error is displayed until the missing or failed battery is replaced.

The battery system supports a 5 second ride-through capability to handle a brief AC power outage of up to 5 seconds. During this brief outage, the battery powers the node, which continues running normally. During this ride-through phase, the node can withstand these brief power outages and can remain available to service host I/O requests. If AC power is restored within the ride-through period, the node continues running normally and does not shut down.

The batteries periodically recondition to maintain an accurate calibration of the full charge capacity of the battery. Reconditioning is automatically scheduled to occur approximately once every three months, but is rescheduled or canceled if the system loses redundancy. In addition, a two-day delay is imposed between the recondition cycles of the two batteries in one enclosure.

A battery loses its capacity to hold a full charge as it ages. When the system detects that a battery's full charge capacity is approaching that which is required to perform a single "fire hose" dump, a near-end of life event is logged. Each battery is assessed independently for near-end of life conditions. A near-end of life event is not fatal, and since the system combines the charge available from each battery, it is possible for the node to remain active while each battery reports a near-end of life event. When the system detects that the combined charge from each battery is not sufficient to perform a single "fire hose" dump, a fatal node error 570 (insufficient charge) is reported, and the node enters service mode. The batteries must be replaced. The full charge capacity of a battery is determined during a recondition cycle, which is run on only one battery at a time. There is a minimum of 48 hours between recondition cycles.

While the node is running, you can remove and install batteries during the following conditions:

• Battery protection is not active and the node is in the Service state. You can check the current state of the node by running the sainfo lsservicestatus command. Both batteries can be swapped in this instance.
• Battery is not discharging or reconditioning. You can check for either state by running the svcinfo lsnodebattery command and checking the charging_status value.

If these conditions are not met and you attempt to remove or install a battery, the node might automatically enter the Service state. If the node is powered by one battery during a full system state dump, the node might shut down.

To determine whether it is safe to remove the battery, enter the following chnodebattery command.

svctask chnodebattery -remove -battery battery_id node_id

If it is not safe to remove the battery, the command fails with a BATTERY_NOT_REDUNDANT error code.

Battery location

The batteries are located in the front of the node. Figure 1 shows the battery locations on a 2145-SV1 node. Each battery has a fault indicator; however, only the fault indicator for battery 2 is shown in the figure.

•  1  Batteries
•  2  Battery Fault indicator

Figure 2 shows the location of the battery fault and status indicators on a 2145-DH8 node.

•  1  Battery 1
•  2  Battery 2
•  3  Battery Fault LED
•  4  Battery Status LED

If a battery fails, its Battery Fault LED lights. You can identify a battery by using the management GUI or by running the chnodebattery -identify CLI command. The Battery Fault LED flashes on the identified battery.

Each battery has a single LED on its bezel, called the Battery Fault LED. It is lit solid if a fault is on the battery. The LED flashes if the battery is being identified.

Note: A Battery Fault LED that is not lit does not indicate that the battery is actively providing protection. You must run the svcinfo lsnodebattery command to determine protection status.

To access information about the battery in the management GUI, select Monitoring > System. On the System - Overview page, click the directional arrow next to the enclosure that contains the battery module. Select Battery Module under Internal Components to display information about the battery module. To display information about the battery in the command-line interface, use the lsnodebattery command.