It's stormy here in the Pyrenees this year and we are experiencing a lot of brownouts. The brownouts are long enough that the NAS reboots and then grumbles for a while whilst it verifies all the files.
A small UPS was needed, but not something that is going to cost the planet. I have several UPS, mostly APC and they are shockingly wasteful. So much so, that I use the best one on the PC and turn it off when the PC is off. The rest of the time I don't care about the energy it wastes as the solar panels 'pay'
The NAS uses a 5.417A/12V external psu and a barrel plug. I contacted Asustor a few years back to ask what the tolerance was for the 12V input. They refused to answer the question. Reading between the lines, they didn't know. I guessed that the 12V was used to just power the hard drives. Picking a few SATA disks at random, the spec was the standard +/- 10%, meaning 10.8V to 13.2V. This almost fits quite nicely into a standard lead acid battery. Li-on is no good as 10.8V is pretty much fully charged.
The AS6202 takes ~1.5A at 11V, 25% cpu & ram, 2 SATA disks. Using a fully charged, 20 year old Yuasa 7Ah/12V (measured capacity 3.5Ah) I got the following. The battery was connected to a Y connector with the normal psu. A 1n5400 diode and a 2.6A fuse.
SLA 12.38V off load.
PSU off. SLA 12.03V. Volt drop across ammeter 0.17V, across diode 0.811V. 10.98V to NAS. Bleed through diode when psu on <0.2uA
I'm not going to get a lot of battery back up, but brownouts are avoided. I'll charge the battery monthly (disconnected)
In due course (!) I'll put LVD protection for the battery.
Some of the items in the house are supported by a Victron Multiplus II which is semaless in keeping the power on, but not the NAS. The NAS is wired to the router, and the router is a lightning conduit. I don't want lightning to get to mul
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