Announcing: Cold Temperature-Tolerant Custom Battery Pack
Our preferred battery chemistry for our clients in Caliente is lithium iron phosphate (LFP). This intrinsically safe chemistry offers the longest lifespan (e.g., 10-15 years) among available options and is sufficiently energy-dense to be space-efficient.
However, there’s one caveat.
LFP cells should not operate under 35 degrees Fahrenheit. They’ll charge, but they’ll also break. High-quality cells come with protective circuitry that stops the cells from charging when the temperature drops below 35 degrees, preventing damage. However, many lesser-quality ones (e.g., random brands on Amazon) don’t have that safety feature.
While our custom-built battery packs all have protective circuitry, the problem remains — the LFP batteries can’t do what they’re supposed to do (charge and store energy) when the ambient temperature gets too low.
Typically, that isn’t much of an issue in residential applications since all solar equipment should be housed indoors anyway. But “indoors” is somewhat interpretive in rural areas like Caliente.
Many of our clients want to put their solar equipment in a shed or pump house. Technically, that’s “indoor” because the environment is shielded from the elements. However, there’s no guarantee that the inside temperature won’t drop below freezing on rare occasions during the winter.
If the LFP batteries don’t charge under those conditions, we have a problem!
Lithium cobalt oxide (LiCoO2) batteries come to the rescue because they can charge in freezing conditions. However, they don’t have LFP’s high-endurance characteristics and longevity.
So, we make LiCoO2 and LFP play nice to get the best of both worlds.
Most, if not all, battery engineers would tell you that you CAN’T mix battery chemistries. Here’s where we say, “Hold my beer.”
Our proprietary software technology makes mixing battery chemistry possible. Our cold temperature-tolerant battery packs consist of mostly high-endurance LFP cells for longevity and the biggest bang for the buck. It also has a smaller LiCoO2 component for added resiliency during cold winter days.
Now, you may wonder, if the lifespans of LFP and LiCoO2 are different, what happens when the LiCoO2 cells die?
Most, if not all, battery engineers would tell you that you CAN’T mix battery cells of different ages — meaning you must toss out the whole pack, erasing LFP’s longevity benefits.
Well, hold our beer again.
Our propriety technology also allows us to mix cells of different ages. When the LiCoO2 pack throws in the towel (e.g., in about 7 years), our clients simply give us a shout, and we swap out the LiCoO2 cells without throwing out the LFP ones.
Meanwhile, all lithium batteries are virtually maintenance-free. Once you have the battery packs wired up correctly, you don’t have to worry about them for years. (Unless you’re us. We name our batteries and talk to them.)
