L R AS Published on Monday 27 September 2021 - n° 375 - Categories:residential storage
How long does a residential storage battery last?
How long does a residential storage battery last?
40% of Americans are concerned about power outages. 70% of those considering installing solar panels plan to add a storage system. Yet only 8% of
of residential solar systems are equipped with batteries. Over 90% of the market is captured by LG Chem and Tesla Powerwall. The latter controls over 60% of the market.
Tesla storage has a limited warranty: the manufacturer claims that during the first ten years of installation, the equipment will not have any defects. However, it is subject to continuous degradation. LG claims that its system will retain 60% of its nominal energy capacity (9.8 kWh) for ten years. The battery must operate between -10°C and +45°C to remain under warranty. The total energy throughput under the warranty is limited to 27.4 MWh.
The batteries now have technology that allows them to intelligently schedule the import and export of energy.
According to the installer Sunrun, the batteries can last between 5 and 15 years. The life of the batteries depends mainly on the usage cycles. The thresholds of 60% or 70% capacity are guaranteed for a certain number of charge cycles. According to the Faraday Institute, degradation comes from overcharging. This occurs when current is injected into a fully charged battery, or during trickle charging when the battery is continuously charged to 100%, and losses inevitably occur. The bounce between 100% and just under 100% can raise internal temperatures, reducing capacity and life.
Another cause of degradation over time is the loss of mobile lithium ions in the battery. Secondary reactions can trap free usable lithium, gradually decreasing capacity.
While cold temperatures may prevent a lithium-ion battery from working, they do not actually degrade the battery or reduce its effective life. The overall life of the battery is reduced at high temperatures, however, as the electrolyte between the electrodes decomposes at high temperatures, causing the battery to lose its ability to transport Li-ion.
In practice:
Install batteries in a cool, dry place. They should be spaced far enough apart to allow for cooling. If possible, avoid repeated deep discharges of batteries, as the more they are discharged, the shorter their life.
https://www.pv-magazine.com/2021/09/23/how-long-do-residential-storage-batteries-last/
PV Magazine of 23 September 2021
