Repair Apple RAID card battery

Question

I have an Apple RAID card Mac Pro (Early 2009) RAID Card (top picture) with a bad battery. Unfortunately these batteries usually die after a few years and the replacement is not cheap. Looking on ebay, I can only get them from the US, but I live in Europe and it will cost me at least $150.
From what I suspect reading the case, the battery is a 3.7 V Lithium battery, probably with built-in electronics that I can perhaps get for $5 from China. Any soldering work is not a problem. If I can replace the digitizer of an iPad mini, I can probably replace a battery too.
The case of the battery looks like a regular aluminum box and the lit is probably just glued onto the battery. It's seems quite sturdy and would require some force to open. Has anyone ever opened an Apple Raid Card battery? I'm reluctant to apply much heat to open the case, though external heat might be ok. Any ideas? I'm aware of the risks.

Answer 1

To summarise the 'end of days' issue with RAID5 the problem is that with the much bigger size of hard disks now available and being used e.g. 4TB or even bigger, it takes so long to rebuild a RAID5 array when replacing a faulty drive that the chance of another drive failing during the rebuild is becoming more and more likely. This is actually made worse by the fact that a RAID rebuild causes a lot of activity and therefore 'stress' on the hard disks in order to do the rebuild process. It can take more than 24 hours to do a complete RAID5 rebuild and during all that time you are vulnerable to a complete failure.
RAID6 is a partial solution in that you start off with redundancy provided by two drives rather than RAID5 which has just one so RAID6 can survive two drive failures. It however only reduces the chances of having a complete RAID failure during a rebuild it does not eliminate it.
Standard RAID5 or RAID6 therefore is being increasingly viewed as having reached a brick wall.
For Enterprises i.e. those with lots of money you can just throw more drives at the problem e.g. RAID10. For the rest of us the hope is on new alternatives to RAID5. The one I am particularly excited about is BTRFS, this is a combination of both a RAID layer and a file-system layer, it is able to use file checksums from the file-system layer to spot and fix RAID issues and this is orders of magnitude more efficient than having to do a complete RAID resync/rebuild. This approach has two advantages, firstly it protects a problem described as 'bit rot' whereby a byte or block in a file can become corrupted, the checksums allow this to be detected and automatically fixed, the second is that it can do a rebuild of actual real data whereas a normal RAID rebuild rebuilds all blocks on a drive even empty ones.
BTRFS is still pre-release especially its equivalent of RAID5 and RAID6 but it is getting closer. (RAID 0 and 1 for BTRFS are already considered ready for use.)
ZFS is a similar 'new' file-system to BTRFS and at one point there was talk that Apple were going to switch to using ZFS but this no longer looks like happening. ZFS was a solution being developed and 'owned' by Sun Microsystems who are now part of Oracle. BTRFS is free open-source.
I personally hope that Apple at some point implement BTRFS.
There are some NAS manufacturers already implementing BTRFS however they are currently 'cheating'. NetGear for example use BTRFS on their current ReadyNAS OS 6.x models but rather than using a 'pure' BTRFS approach have a implemented BTRFS on top of a standard RAID5 system created by mdraid. They did this because as I mentioned above the official BTRFS RAID5/6 solution is not yet ready for real-world use. As a result you get some of the benefits of BTRFS like being more easily able to expand the size of a file-system, but you don't get the full checksum derived protection of BTRFS because it is not integrated to the RAID level. Thecus I believe have gone the same approach as NetGear. Synology and QNAP are still waiting for BTRFS to be 'finished' before implementing it.