An excellent article here: https://www.servethehome.com/raid-controller-batteries-time-bombs-you-need-to-replace/

Are RAID controller lithium-ion batteries ticking time bombs within your server? Over this past weekend, we saw an IBM ServeRAID battery pack that looked ominous. Everyone knows that RAID controller batteries need to be replaced at regular intervals. That is one of the key drivers towards supercapacitors on RAID cards. Before this weekend, our assumption that it was a matter of keeping data safe in the event of a power failure. After this weekend, we now think it may be a safety issue.

My question is, which modern RAID controllers have done away with batteries and now use strictly supercapacitors (and maintenance free)?

Google points me to this @ https://www.ibm.com/support/knowledgecenter/POWER9/p9ed5/ared5pcie3comp.htm but I am after a non-OEM'd units if possible to avoid me having to buy vendor locked HDD.

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    In HPE land, we've gone from batteries to SuperCaps back to batteries. – ewwhite Jul 23 '20 at 15:48
  • Any specific reason that you may know of? Using HPE servers personally had a bad experience with dead after dead BBU, whereas DELL were always rock solid – morleyc Jul 23 '20 at 15:50
  • @ewwhite LSI and DELL PERC cards use capacitors to save DRAM content in on-board flash in case of power failure. From what I can see, it works very well and provides way longer lifetime than a normal battery. Do you know why HP went back to batteries? Thanks. – shodanshok Jul 23 '20 at 16:34
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    You can predict battery is failing or about to fail (voltage monitoring), but with capacitor it’s one big surprise always. – BaronSamedi1958 Jul 23 '20 at 16:47
  • @shodanshok HPE moved to the Smart Storage Battery in recent years on the Gen9/Gen10 platform. This connects to the system board and powers up to 24 devices, including RAID controllers and NV-DIMM modules. So it's a centralized backup battery source for the chassis, rather than individual BBWC/FBWC for controllers. – ewwhite Jul 23 '20 at 20:38

Adaptec does such a thing.



Supercapacitors aren’t maintenance free, they have lifetime of 10–15 years (typically), but hey I have Sun machines running since 2008.


  • 3
    AMAZING! This is all news to me, stuck in the past of blown BBUs! Thanks you very much - any specific model you would recommend for SAS/SATA for around $700 (inc said supercapacitor)? – morleyc Jul 23 '20 at 15:40
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    I’d love to, but we’re using dark side of the force - ZFS & Ceph :) – BaronSamedi1958 Jul 23 '20 at 16:48
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    Yup looking into it in more detail and realised hba and freenas, hyper converged appliances are much better for my use case. That one comment was a moment of relaisation and allowed a definitive decision to be made. Thank you – morleyc Jul 24 '20 at 21:12
  • Great :) Good luck! – BaronSamedi1958 Jul 25 '20 at 9:28

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