LiFePo4 In The cold?

[Lost_in_the_HTTP]

I have a UPS in the garage and another out in the shed for network devices including cameras on POE switches.

SLA batteries haven't been holdong up even insidfe tehn hosue for more than a couple of years. I'm switching most of them over to LiFePo4 batteries which seem to be doing fine. But I got to wondering about those two potentially cold locations. We don't get months below freezing, but we can get days to maybe a week or more.

I see these:

https://www.batteriesplus.com/blog/power/lithium-batteries-cold

https://www.redway-tech.com/can-you-store-lifepo4-below-freezing/

One talks about charging them in the cold (which a UPS does constantly) and says they're better than SLAs in the cold. The other talks about wrapping them or using a stick on heater.


Thoughts? Experiences?

 

[jmagg]

Learn About Batteries

Battery University™ is a free educational website offering hands-on battery information.

batteryuniversity.com

 

[Red Squirrel]

You can't just swap in batteries like that in a UPS, you need a battery management system, as well as circuitry to balance charge the cells. They have some rather specific charging stages, some are constant current. UPSes just charge at a constant voltage across all cells, which is ok for lead acid but not lithium.

Replace them with flooded lead acid batteries, and those will last longer, just need to add distilled water to them once a year. Bonus is the extra run time too.

If you do manage to rig something and manage to use lithium batteries make sure they are heated.

 

[William Gaatjes]

You can't just swap in batteries like that in a UPS, you need a battery management system, as well as circuitry to balance charge the cells. They have some rather specific charging stages, some are constant current. UPSes just charge at a constant voltage across all cells, which is ok for lead acid but not lithium.

Replace them with flooded lead acid batteries, and those will last longer, just need to add distilled water to them once a year. Bonus is the extra run time too.

If you do manage to rig something and manage to use lithium batteries make sure they are heated.

Indeed.

I have a UPS in the garage and another out in the shed for network devices including cameras on POE switches.

SLA batteries haven't been holdong up even insidfe tehn hosue for more than a couple of years. I'm switching most of them over to LiFePo4 batteries which seem to be doing fine. But I got to wondering about those two potentially cold locations. We don't get months below freezing, but we can get days to maybe a week or more.

I see these:

https://www.batteriesplus.com/blog/power/lithium-batteries-cold

https://www.redway-tech.com/can-you-store-lifepo4-below-freezing/

One talks about charging them in the cold (which a UPS does constantly) and says they're better than SLAs in the cold. The other talks about wrapping them or using a stick on heater.


Thoughts? Experiences?

SLA batteries do have the tendency to get lazy after a few years. That is why you regularly need to discharge them. But even then, these batteries age over time after a few years. It just happens.

Totally different chemistry. Different voltages, different charge currents , different charge voltages and different charge method.
If you are willing to invest time and money into a sufficient charging system and are able to integrate that into your existing UPS system. Then it is possible. But i doubt that it is that easy as your post make it sound.
You would need electronic schematics and everything.
There is probably even a programmed microcontroller in there, in the UPS that would not just accept a different battery.
Is it worth the hassle ?

 

[Lost_in_the_HTTP]

I have five in place that have been working fine for weeks to months.

 

[dullard]

I have a few LiFePO4 batteries as a partial home UPS. All of mine can discharge from -4°F to 104°F but can only charge from 32°F to 104°F. These numbers are pretty typical for the industry. To go colder, there are self-heated batteries.