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Comment by nwah1 | Hacker News Reader

Also have one. Also replaced the battery. The other thing I don't like about it is that the battery is lead-acid, which is extremely toxic and extremely heavy. But when I looked into that, I could not find any manufacturer that offered a consumer grade lithium-ion product.

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Food for thought: lead-acid batteries are the most recycled things on earth, at around 99%. Probably because they tend to be large, so they have a high volume to surface ratio, and are relatively simple and easy to recycle compared to more modern battery types, and many automotive related companies are required to have recycling programs for them, and they've been around for many decades ...

Fair enough. But if it is in an electrical device with shoddy glue that is likely to catch fire or explode, then it would be nice to not be given a lethal dose of lead in addition to my place burning down.

Being exposed to burning alkali metals isn't great either. I guess the chronic health problems that creates are less "silent" though.

Personally,.I would much prefer my odds as an adult in a lead poisoning/fire situation than a similar li-po situation. Going with the more complex battery is basically choosing a future of experimental medicine over treatments with long and successful track records.

Lead-acid is the better battery for something that is going to sit fully charged for long periods of time.

Asbestos is still unbeatable for fire protection.

Nah, PFLOS is more deadly, so thereby making it better

Laptops have proven Li-Ion works well enough, too

Laptops typically get replaced every 3-4 years, and a major requirement for them is to be lightweight. Lead acid batteries are far more economical for applications where weight is not a concern.

I'm giving some thought to brewing up my own UPS. Mostly for capacity, which is tough to get in a residential unit at any price, and quickly becomes expensive if you try. Technologically, it is not particularly difficult. You buy a halfway decent inverter/charger from a reputable manufacturer, and however much LiFePO4 capacity you want. I would not choose lithium ion; LFPs are considerably less likely to combust.

Please post a parts list if you do!

How do you achieve the X <= 10 ms switching capacity? You need this if you actually want your equipment to survive the power outage.

Also, I'm extremely sensitive to humm noise output by inverters so I can only tolerate UPSs that have that "Green mode" option which (I guess?) powers directly from AC when under quality power but still provides protection.

Capacitors or using a circuit where the battery is always supplying power (can't remember what it's called).

Could make a post-PSU UPS, then you don't need an inverter at all (also the most efficient design, no conversion losses)

My preferred inverter/charger manufacturer, Victron, has "UPS Mode" for their Multiplus units that will switch in 12ms. That's similar to many UPS's, though some of the higher end ones are sub-10.

A few years ago ESR started on an open source/hardware UPS project called Upside.[0][1] I can't vouch for the design as I haven't looked at it in a long time.

[0] http://esr.ibiblio.org/?p=7839

[1] https://gitlab.com/esr/upside

> which is extremely toxic

Lithium is toxic too and never gets recycled.

> and extremely heavy

Yea, it's like you move your UPS every day?

Toxicity is a relative concept. Lead's toxicity is measured in parts per billion. Lithium is many orders of magnitude safer.

It's not the lithium part of lithium batteries you worry about, it's everything else. Lithium hexafluorophosphate turning into hydrogen fluoride gas, for example.

I still have my lead acid batter in my UPS from... 2016? I'm not even sure when I got it.

With lithium I need to know when I got it, did it run in non-ideal lithium conditions (-20^C? No go. +34^C? No go), and the most importantly - in three years I need to replace a Li battery, but with a lead battery and a non-online UPS I can have from 3 to 10 years of lifetime from it.

I isn't lithium potentially much more dangerous, especially if the containment is breached?

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