rin67630
Solar Addict
The "loss of capacity" is only temporary. It just means, that at low temperatures the chemical processes are slower. You just cannot push and pull as much energy as you could with a warmer battery. As soon as the battery regains temperature, the energy stored will be available again.Valid question. My interpretation was based on the two things being stated separately in the manual. (it should be noted that the 50% loss of capacity wasn't until -40° C. At -20° C the loss was only 25%.) The state of charge was to be determined by voltage. Maybe I'm interpreting this wrong. Its probably irrelevant anyway because if you are optimizing performance, you never go below 50% state of charge even when the temperatures are warm.
(By comparison and with the same criteria, a LiFePo has a 100% loss of capacity under 0°C, you should not charge it at all!)
Under real operation at latitudes > 50°, you should design your off grid system to be able to operate long time without energy income anyhow. That means design it for discharge rates far lower than C/100. Unless you live at high altitudes or in polar regions your thermically insulated battery will not drip under critical temperatures. Currently, I just do not know any chemistry that it's better able to deal with low temperatures than lead-acid.
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