SA E200 / 128 write cache is disabled

[Rafik Nashed]

I've server ProLiant ML150 G3 with smart array E200/128. Now I've this message in booting after check the array:
"1744-slot 0 Drive array - Array Accelerator Battery Charge Low.
Array Accelerator posted write cache is temporarily disabled.
Array Accelerator will be reenabled when Batteries reach full charge."
My server is very slow and have alot of problems with it after this message is appears.
PLS advice what can I do?
Thanks in advance.
Rafref