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Comment by deeesstoronto | Hacker News Reader

I've had a bunch of APC SmartUPS 1500 in both tower and rack formats.

I found the batteries in the rack version, where batteries lay on their sides, reach end of life much sooner than the tower version, where batteries are upright.

It's likely poorer heat dissipation/ventilation in the rack version, but may have to do with battery orientation. The rack version also seems to suffer corrosion damage from battery off-gasing if batteries reach critical failure and overheat. I haven't seen the same damage on the tower units. Again some combination of orientation and ventilation.

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The batteries are sealed lead acid AGMs. Where orientation isn't a concern because the electrolyte is gelified in fiberglass. Also, they shouldn't be off-gassing at all. That's the sealed part. I've had SLA batteries puff up. And if you are getting corrosion in and around the AP chassis you may have a leak.

Typically, what determines the life of these batteries is # of cycles and # of deep discharges. The more extreme the environment the shorter the life time. I have network equipment sit outdoors in a cabinet. The batteries typically last 24-36 months instead of the 48-60 months I see from indoor UPSes.

orientation isn't supposed to be a concerned with SLA batteries, but it's probably nicer for them to be upright than not... when the seals do fail, it's better to have the electrolyte seep out and stay on top than seep out and drip onto something else.

Wow, outside?

I recently had a Supermicro board die because it became infested with moths out in the garage, it was disgusting and the board was borked even after extensive cleaning.

How do you keep wildlife at bay? (insects and rodents are attracted to heat and shelter).

Maybe some kind of solid metal cabinet enclosure like the public utility boxes along some roadside thoroughfares?

In a garage environment, using mesh everywhere and ensuring there are zero openings like an empty PCIe slot is the best solution.

Outdoors you need special enclosures typically made for industrial computers; and many companies build special fanless enclosures that dump heat directly through the metal enclosure (it is basically the heat sink).

Others have fan designs that have their intake and exhaust through filters on the bottom.

Yeah, I haven't yet researched what kind of mesh to use, any recommendations there? Thank you!

Honestly in a pinch I've used screen door mesh from the hardware store, and gaff tape.

Otherwise, search online for 'PC dust mesh filter' and it usually is sold in rolls.

The circuit board for a UPS and the board for a motherboard aren't really the same. One is designed for high voltage/high current and conformal coated in epoxy. The later has much tighter tolerances and is optimized for low voltages/high frequencies. And it's probably not conformal coated.

I could believe the consumer models are actually built to a higher standard. A rack mount unit is likely going to be climate controlled, minimal vibration, actively monitored, etc. The consumer units will be subjected to all manners of hell: pet hair, zero ventilation, installed and forgotten. Nobody wants the UPS to burn down the house.

In my experience, server grade stuff tends to be significantly more reliable (as long as it doesn't become infested with insects or something odd like that :p).

My consumer machines are generally flaky as hell in comparison.. maybe partly due to windows and gfx card drivers? Ymmv.

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