If solar streetlights use lithium batteries, how can their lifespan be extended? TIANXIANG, a professional Chinese solar street light producer, explains the solutions.
1. Prevent Overcharging Of Solar Street Light Lithium Batteries
The lifespan and performance of solar street light batteries are closely related to the heat accumulation inside the battery. The main source of heat is the power loss from internal electrochemical reactions, which can be simply viewed as the product of charging voltage and charging current. More heat is produced in the oxygen recombination reaction as the float current rises. The temperature rises as the float current rises during constant voltage charging. Because of the way valve-regulated sealed batteries are constructed, thermal runaway is a special phenomenon. Thermal runaway frequently causes major damage, including water loss from the battery and bulging of the casing, and in extreme situations, it makes the battery unusable. The charging voltage values specified in the manufacturer’s instructions for the solar streetlight must be closely followed in order to avoid overcharging. Modern combined power supplies can be configured and intelligently managed. It is important to ensure correct configuration and that unauthorized personnel do not arbitrarily modify the settings.
2. Prevent Insufficient Charging of Solar Street Light Lithium Batteries
Insufficient charging, the opposite of overcharging, is mainly caused by a charging voltage setting that is too low or too low. It could also be due to a problem with the rack system.
3. Prevent Over-Discharging of Solar Street Light Lithium Batteries
The depth of discharge is closely related to the battery’s designed charge-discharge cycle count (lifespan). For example, a 5% depth of discharge corresponds to 10,000 cycles, while a 50% depth of discharge only results in 800 cycles. Severe over-discharge can prevent the battery from being reactivated to its optimal state, or even render it unusable. Different discharge rates result in different discharge times and termination voltages, as well as different effective capacities, and are also affected by ambient temperature. Related curves are not listed or plotted here; they are provided in the battery manuals of different manufacturers. Maintenance personnel should pay attention to these and strictly adhere to the relevant data settings in the monitoring unit, avoiding arbitrary changes. Modern rack power supply manufacturers design battery power-off functions, automatically cutting off the battery discharge circuit via monitoring commands when the solar street light battery discharges to the set termination voltage. Some manufacturers have even included a forced disconnect circuit in place to prevent the monitoring unit from detecting the battery termination voltage or issuing commands due to unforeseen circumstances (depending on its power supply). As a result, during routine inspections and necessary checks and maintenance, maintenance staff should also focus on the hardware circuits’ dependability.
4. Managing the Outside Climate
Increased float current, decreased internal resistance, and increased electrolyte activity all result in accelerated corrosion of conductive components and a shorter lifespan when the battery temperature rises. The battery’s ability to discharge to the load is weakened when electrolyte activity declines because internal resistance is decreased. Thus, keeping an eye on the solar street light battery’s temperature as well as managing and preserving the surrounding air temperature are crucial. Temperature compensation for the charging voltage is also necessary to avoid overcharging at high temperatures and undercharging at low temperatures. In most places using battery packs, the ambient temperature is controlled at around 25 degrees Celsius. Accelerated life tests show that a 10-degree Celsius increase in ambient temperature without adjusting the charging voltage will halve the lifespan of the solar street light lithium battery.
5. Solar Streetlights Require Timely Replacement Of Faulty Batteries
Due to differences in the manufacturing process of each individual cell, long-term float charging may cause them to gradually “fall behind.” In order to reactivate the lagging cells and keep them from falling behind again, the monitoring unit has a management function that periodically charges the battery pack using equalization. However, a defective battery may eventually result from persistent lagging. A battery’s capacity can be tested individually or its internal resistance can be tested online, among other techniques, to ascertain whether a battery is beyond repair. The key is to replace faulty batteries promptly, as this is crucial for the availability and even the lifespan of the solar street light lithium batteries pack.
Post time: Mar-03-2026