The title says it all. I am trying to troubleshoot a problem with the battery in a BBU RAID cache. During POST, an error is given something to the effect that the battery is low, the RAID cache is temporarily disabled and will begin working once the battery recharges. The battery is a 3.6v Ni-HM rechargeable battery, but when I take it out and measure its voltage, it is around 5v, no load. Originally, I assumed that this was because it was not under load, but as it turns out it reads the same voltage when I power on the server. This is very confusing to me, that a dead battery would have a higher voltage than it is supposed to.
I only run the server for around 6 hours each day. Is it possible that the battery discharges over night?
As a side note, I have tried connecting a pack of two AA batteries in place of the 'official' battery, but still don't have any luck. (By the way… If you ever do that, don't use alkaline batteries. They explode. You have to use rechargeable batteries. I speak from experience.)
I really need the extra performance boost of the cache, and so am willing to run the server 24/7 to keep the battery charged, but I don't want to if I don't have to.
For Clarification, my server is an HP Proliant ML350, with an HP Smart Array E200i RAID controller.
Best Answer
The battery recharge through the power provided by the PCI-express slot which, when the server is powered down, has only access to a very limited power source.
So, the battery should not recharge when the server is off.
Rather than trying other battery, get a compatible one and check if the error message disappear.