You might consider updating the controller firmware (after BIOS, ESM, and controller driver are updated), which controls the state of the battery.  Otherwise, the battery you linked to should be fine ... there aren't really other "kinds" of batteries that will work.
Hello All, I have a general question I need help answering: Server is a Dell PowerEdge 1950  I have a E1211 ROMB BATT on the LCD Screen and want to replace the battery. With the specs above showing as our part number based from the Service Tag, would the following link below be ok to order from? [URL]  Are there better kinds of batteries this RAID controller could use vs. the one we are planning on ordering?  Please advise. Thank you, Hiphoptech
Perc 5i RAID Controller Battery Replacement Question 