Sun StorEdge[TM] 3510/3511 FC Array/3310/3320 SCSI Array: Battery Display on Firmware GUI Appears to Be Incorrect

Asset ID:	1-72-1001846.1
Update Date:	2009-11-08
Keywords:

Solution Type Problem Resolution Sure

Solution 1001846.1 : Sun StorEdge[TM] 3510/3511 FC Array/3310/3320 SCSI Array: Battery Display on Firmware GUI Appears to Be Incorrect

Related Items


Sun Storage 3510 FC Array
 Sun Storage 3310 Array
 Sun Storage 3511 SATA Array
 Sun Storage 3320 SCSI Array

Related Categories


GCS>Sun Microsystems>Storage - Disk>Modular Disk - 3xxx Arrays

PreviouslyPublishedAs
202529

Symptoms
The battery display at the top of the firmware graphical user
interface (GUI) display is correct when the battery is in a
charging state, but the display is incorrect when the
battery is in a discharging state.

Sometimes, the battery level seems
to drop to "++---" and the battery LED that indicates when the
battery is charging does not flash.

How low can the battery level drop before it is recharged?

Resolution
The battery charger behavior is difference for Li-ion batteries than it
is for Ni-MH batteries.

Note: Currently, Sun StorEdge[TM] 3510/3511 FC Array and 3310 SCSI array use
only Li-ion batteries.

For Ni-MH batteries, the charger produces a constant trickle charge, so
during the power on, and after the Ni-MH battery has been fully
charged, the Ni-MH battery always stays at a full capacity state.

For Li-ion batteries, safety reasons dictate that there is no constant
trickle charge. The battery charging circuit is only activated
after the battery voltage drops to 3.9V. The following table shows the
relationship of the GUI battery display and battery voltage/capacity
during battery charging state for an Li-ion battery:

 Battery Display      Battery Voltage       Battery Capacity
--------------------------------------------------------------
+++++               > 4.2V                  100%
++++-               < 4.20V                < 100%
+++--               < 4.05V                < 80%
++---               < 3.96V                < 60%
+----               < 3.84V                < 40%
-----               < 3.76V                < 20%

Confusion can result because for an Li-ion battery with a particular
voltage level, the battery capacity is different in charging state than
it is in discharging state.

For example, during the charging state, 3.95V means there is a 60%
battery capacity (refer to the preceding table), but in a discharging
state, 3.95V means there is still over 93% battery capacity remaining.
The 93% is determined from actual testing on the arrays with
512 MB DIMM. When the battery voltage drops to 3.95V and you
disable the charger, the DIMM data is retained for over 100 hours.

Because the charging time is very short and the charger does not
activate until the voltage drops to 3.9V, the battery is in a discharging
state most of the time. The battery display in the firmware GUI is based
on the voltage level of battery in the charging state only. Therefore,
although the battery still retains over 93% capacity and can keep data
over 72 hours to prevent loss during power outages, the battery display
may show only "++---" or "+++--".

Product
Sun StorageTek 3510 FC Array
Sun StorageTek 3310 SCSI Array
Sun StorageTek 3320 SCSI Array
Sun StorageTek 3511 SATA Array

3510, 3511, 3310, battery, 3320
Previously Published As
71446

Change History
Date: 2004-10-19
User Name: 7058
Action: Approved
Comment: Straightened out the battery display chart so that it appears aligned in
preview. Rest of doc is fine.
Publishing.
Version: 2
Date: 2004-10-19
User Name: 7058
Action: Accept
Comment:
Version: 0

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