When living in extreme conditions, a reliable power source is an absolute necessity. To make sure your battery can handle the cold, it’s important to consider how weather affects them. Lead-acid batteries tend to be less efficient than lithium when temperatures drop below freezing, thus making lithium the top choice for those exploring frigid climates.
Are lithium batteries good in cold weather?
LFP batteries can withstand temperatures ranging from -4°F to 140°F, making them suitable for use in all climates. This is especially advantageous for off-grid solar, RV and Camper Van owners who may be exposed to low temperatures. Lead-acid batteries are more sensitive to cold environments and tend to loose performance when consistently discharged with such weather conditions. Lithium on the other hand is known for working well at colder temperatures and actually adding voltage and reducing resistance when in use. It’s obvious that lithium is the go-to option when considering power options in cold weather.
Does cold weather affect lithium battery life?
Even lithium batteries are affected by cold weather. At temperatures below 32 degrees, lead-acid batteries will perform at 70-80% of their rated capacity. At the same temperature, lithium batteries can operate with very little loss, providing 95-98% of their capacity with very little loss.
At temperatures above freezing, lithium ions are readily absorbed into the porous anode, but when it’s colder than that, they tend to coat the surface, a process known as lithium plating. This limits its availability for generating electricity and reduces the battery’s capacity while also making it mechanically unstable and more susceptible to sudden failure. The improper charging of a sub-zero battery further exacerbates these issues.
It is difficult for lithium ions to locate themselves within the graphite anode during freezing charging. Instead of intercalating, these ions end up plating the anode’s surface. Plating can reduce battery capacity and increase resistance when charged in freezing temperatures. When enough plating accumulates, it can puncture the separator and lead to a dangerous short inside the cell.
How To Charge Lithium Batteries In Cold Weather
When you want to protect your investment, charging in cold weather requires a different protocol. Nearly every battery requires a longer charging process when the temperature drops. Charge conditions for lead-acid batteries are less flexible than those for lithium batteries. However, they must be charged at a slower rate and within their temperature ranges.
The effects on battery life when being charged in colder temperatures is proportionate to the charging rate. Slower charging is a solution in order to minimize damage; however, this typically isn’t feasible. If temperatures range between 32 and 14 degrees Fahrenheit, charging must be kept under .1C. When temperatures fall below 14 down to -4 degrees Fahrenheit, charging speeds must not exceed .05C. This will certainly lengthen the amount of time required for a full charge as well as make the process more difficult since predicting in advance how cold it might get during a charge cycle is impossible. For instance, you may start to charge at 40 degrees before bed but by morning have experienced an unexpected drop into the 18-degree range; if charging had been set at a higher speed overnight, the lower temperatures could potentially cause harm which cannot be reversed.
In cold weather, the number one rule is to do not charge your batteries without reducing the charge current when the temperature falls below freezing. Unless your BMS communicates with your charger, and the charger is capable of reacting to the data provided, this can be difficult. The charge current must be 5-10% of the battery capacity if you charge below freezing temperatures.
What is the best battery for cold weather?
Charging lithium-ion batteries at temperatures below freezing will permanently damage them. The only solution in the past was to have the battery above freezing temperatures before charging it, if a Battery Management System (BMS) did not communicate with a charger that was programmed to reduce the current in those conditions. You could either do this by placing them in a warmer environment or by wrapping them in a thermal blanket to keep them warm.