6 ms·

I've heard that it's a terrible idea with the battery still in. Curious why this is a non-issue for a UPS -- is it the scale, type of battery (lithium ion vs li

I've heard that it's a terrible idea with the battery still in. Curious why this is a non-issue for a UPS -- is it the scale, type of battery (lithium ion vs lifepo4), quality, charge cycle, a bit of all of the above?

selectodude 2y ago
It’s not a non-issue. UPS batteries have a rather short lifespan.
- HPsquared 2y ago
  That's surprising. My laptop battery is like 10 years old and still fine. Light usage and mild storage conditions. Surely UPS batteries are similar.
  - pmontra 2y ago
    My UPS manual says 3 years. They have a different chemistry than phone batteries. On the other side, they should be quite similar to car batteries which could live much longer that 3 years, but they spend most of their time waiting in a parking slot and then a few starts per day or less. An UPS doesn't work like that.
    - bityard 2y ago
      A good UPS will perform regular load tests to gauge battery performance/degradation. They switch over to battery power around once a week and measure voltage before, during, and after. So even if the power goes out, they are still being exercised _somewhat_.
      - password4321 2y ago
        Can you link to one of these on Amazon or your preferred vendor which you recommend for home office use?
        TsiCClawOfLight 2y ago
        Eaton Ellipse Pro is great.
  - bityard 2y ago
    UPS batteries tend to have lead acid batteries, and the lifespan on those is generally between 3-5 years. Lithium batteries in laptops _can_ last quite a bit longer if made well and under the right care.
theanonymousone 2y ago
Really? I plugged my old phone some days ago and set up a ssh daemon on it, just to see if it stays connected. Should I be worried?
- jraph 2y ago
  Yes, it's potentially hazardous in the long run. You can hope that it only kills the battery fast, and that it doesn't make it swell or something. (absolutely not an expert, though, this is why I asked for experiences :-))
- z3t4 2y ago
  It usually take a few years for the battery to swell, but it will happen. I have a phone as GSM modem to send and recieve SMS for automatic tasks. I've had 3/3 batteries on two different phones swell so far.
deleted 2y ago
[deleted]
__MatrixMan__ 2y ago
I think some devices can now be configured to just charge partially (or come that way by default and then tell you that the partial charge is 100%). So this may not be a an issue in all cases, but... I dedicated an Nvidia shield K1 to be a Sonos interface. Just mounted it to a monitor arm and left it plugged in for something like four years. The mount was this beefy metal thing, a little steel cage for the tablet, but as soon as I unscrewed it enough to remove the tablet from the mount the tablet undramatically exploded. It ballooned to a width that was thrice the original thickness of the tablet, pushed the plastic apart, and it was clear that the case was never going to come back together again. I was afraid to touch it, lest it rupture. It seems like it would only be a terrible idea beyond a certain scale. The pillowing battery is just assisted disassembly. And now it's easy to get the battery out.
ssl-3 2y ago
UPSs still typically use lead acid batteries. These don't particularly mind being at ~100% SoC for years at a time (they like staying charged), which is very good for this application. And it's easy to keep them at around 100%. For instance: For a nominal 12v battery, one can very nearly just feed it 13.8v (plus or minus some temperature compensation) and have results that are actually pretty good and close-enough to 100%. And when things go very wrong, lead acid batteries tend not to catch on fire. It's a natural fit for UPS duty. The lithium batteries in cell phones are a different thing. They hate being at 100% SoC and degrade fairly quickly in that state. They can be pretty happy at around 50% SoC, but it's hard to actually keep them there because of the way the voltage ramps [don't] work with lithium chemistries: It's almost flat through the middle of the curve. And cell phones don't let us do that anyway: It'd be great if there was a "Compute mode: Just do your best to keep this battery near 50%" setting to click on, but there is not. (And we could hack that in, except: We don't own our phones.) And when things go wrong, they can become exothermic in ways that are not exactly ideal for an unattended device sitting on a shelf.
- _yb2s 2y ago
  I use a chargie device which is a hardware level charge limiter
  - ssl-3 2y ago
    Cute. I didn't know those existed, and they do make sense. It's only solving part of the problem though: Sure, it can keep the charge at around a self-reported 50%. But the device itself doesn't necessarily have a good idea of what 50% even means, especially as the months and years tick by and cells age, unless it is allowed go closer to the extremes (closer to 0 and closer to 100, sometimes). The reasons for this get weird. Near the edges of the curves (0 and 100), the BMS can use voltages to figure out where things are. This works well. In the middle of the curve, voltages are damn near flat and cease to be an indicator of state-of-charge, so the BMS counts coulombs instead. This works too (for awhile). Except they're not ideal batteries. They age even if they're not being used at all, and shit happens just as it does for any other non-ideal entity. So on a long-enough timeline, even a perfect coulomb counter doesn't necessarily have any way to accurately report state of charge. The way that this problem is dealt with on a phone that actually gets used like phones get used is that the BMS can reset the coulomb counter during the peaks and dips of a normal charge cycle, based on voltage. But charge cycling doesn't happen even with a Chargie-equipped phone sitting on a shelf and running Docker containers, does it?
mmis1000 2y ago
Well, surprisingly. You actually need to swap the battery in UPS about every 3 years. Or the monitor feature in UPS is going to complain _loudly_.(I have one broken a few months ago) So there is not much difference here. Although swapping battery of ups is surprisingly easy. Buy a new one from online store with a few dollar. Disconnect the connection to old battery.(a REALLY important step). Remove old one. Slap the new one in. Connect the wire. And pre-charge it for a few hours. Then it can just go back online like a new one.

selectodude 2y ago

It’s not a non-issue. UPS batteries have a rather short lifespan.

HPsquared 2y ago
That's surprising. My laptop battery is like 10 years old and still fine. Light usage and mild storage conditions. Surely UPS batteries are similar.
- pmontra 2y ago
  My UPS manual says 3 years. They have a different chemistry than phone batteries. On the other side, they should be quite similar to car batteries which could live much longer that 3 years, but they spend most of their time waiting in a parking slot and then a few starts per day or less. An UPS doesn't work like that.
  - bityard 2y ago
    A good UPS will perform regular load tests to gauge battery performance/degradation. They switch over to battery power around once a week and measure voltage before, during, and after. So even if the power goes out, they are still being exercised _somewhat_.
    - password4321 2y ago
      Can you link to one of these on Amazon or your preferred vendor which you recommend for home office use?
      - TsiCClawOfLight 2y ago
        Eaton Ellipse Pro is great.
- bityard 2y ago
  UPS batteries tend to have lead acid batteries, and the lifespan on those is generally between 3-5 years. Lithium batteries in laptops _can_ last quite a bit longer if made well and under the right care.

theanonymousone 2y ago

Really? I plugged my old phone some days ago and set up a ssh daemon on it, just to see if it stays connected. Should I be worried?

jraph 2y ago
Yes, it's potentially hazardous in the long run. You can hope that it only kills the battery fast, and that it doesn't make it swell or something. (absolutely not an expert, though, this is why I asked for experiences :-))
z3t4 2y ago
It usually take a few years for the battery to swell, but it will happen. I have a phone as GSM modem to send and recieve SMS for automatic tasks. I've had 3/3 batteries on two different phones swell so far.

deleted 2y ago

[deleted]

__MatrixMan__ 2y ago

I think some devices can now be configured to just charge partially (or come that way by default and then tell you that the partial charge is 100%). So this may not be a an issue in all cases, but... I dedicated an Nvidia shield K1 to be a Sonos interface. Just mounted it to a monitor arm and left it plugged in for something like four years. The mount was this beefy metal thing, a little steel cage for the tablet, but as soon as I unscrewed it enough to remove the tablet from the mount the tablet undramatically exploded. It ballooned to a width that was thrice the original thickness of the tablet, pushed the plastic apart, and it was clear that the case was never going to come back together again. I was afraid to touch it, lest it rupture. It seems like it would only be a terrible idea beyond a certain scale. The pillowing battery is just assisted disassembly. And now it's easy to get the battery out.

ssl-3 2y ago

UPSs still typically use lead acid batteries. These don't particularly mind being at ~100% SoC for years at a time (they like staying charged), which is very good for this application. And it's easy to keep them at around 100%. For instance: For a nominal 12v battery, one can very nearly just feed it 13.8v (plus or minus some temperature compensation) and have results that are actually pretty good and close-enough to 100%. And when things go very wrong, lead acid batteries tend not to catch on fire. It's a natural fit for UPS duty. The lithium batteries in cell phones are a different thing. They hate being at 100% SoC and degrade fairly quickly in that state. They can be pretty happy at around 50% SoC, but it's hard to actually keep them there because of the way the voltage ramps [don't] work with lithium chemistries: It's almost flat through the middle of the curve. And cell phones don't let us do that anyway: It'd be great if there was a "Compute mode: Just do your best to keep this battery near 50%" setting to click on, but there is not. (And we could hack that in, except: We don't own our phones.) And when things go wrong, they can become exothermic in ways that are not exactly ideal for an unattended device sitting on a shelf.

_yb2s 2y ago
I use a chargie device which is a hardware level charge limiter
- ssl-3 2y ago
  Cute. I didn't know those existed, and they do make sense. It's only solving part of the problem though: Sure, it can keep the charge at around a self-reported 50%. But the device itself doesn't necessarily have a good idea of what 50% even means, especially as the months and years tick by and cells age, unless it is allowed go closer to the extremes (closer to 0 and closer to 100, sometimes). The reasons for this get weird. Near the edges of the curves (0 and 100), the BMS can use voltages to figure out where things are. This works well. In the middle of the curve, voltages are damn near flat and cease to be an indicator of state-of-charge, so the BMS counts coulombs instead. This works too (for awhile). Except they're not ideal batteries. They age even if they're not being used at all, and shit happens just as it does for any other non-ideal entity. So on a long-enough timeline, even a perfect coulomb counter doesn't necessarily have any way to accurately report state of charge. The way that this problem is dealt with on a phone that actually gets used like phones get used is that the BMS can reset the coulomb counter during the peaks and dips of a normal charge cycle, based on voltage. But charge cycling doesn't happen even with a Chargie-equipped phone sitting on a shelf and running Docker containers, does it?

mmis1000 2y ago

Well, surprisingly. You actually need to swap the battery in UPS about every 3 years. Or the monitor feature in UPS is going to complain _loudly_.(I have one broken a few months ago) So there is not much difference here. Although swapping battery of ups is surprisingly easy. Buy a new one from online store with a few dollar. Disconnect the connection to old battery.(a REALLY important step). Remove old one. Slap the new one in. Connect the wire. And pre-charge it for a few hours. Then it can just go back online like a new one.