BU-502: Discharging at High and Low Temperatures

Like humans, batteries function best at room temperature, and any deviation towards hot and cold changes the performance and/or longevity. Operating a battery at elevated temperatures momentarily improves performance by lowering the internal resistance and speeding up the chemical metabolism, but such a condition shortens service life if allowed to continue for a long period of time. Some manufacturers of lead acid batteries make use of the improved performance at warmer temperatures and specify the batteries at a toasty 27°C (80°F).

Cold temperature increases the internal resistance and diminishes the capacity. Batteries that would provide 100 percent capacity at 27°C (80°F) will typically deliver only 50 percent at –18°C (0°F). The capacity decrease is linear with temperature. The capacity decrease is momentary and the level of decline depends on the battery chemistry.

Li-ion also performs better at high temperatures than at low ones. Heat lowers the internal resistance but this stresses the battery. Warming a dying flashlight or cellular phone battery in your jean pocket might provide additional runtime in the winter. As all drivers in cold countries know, a warm battery cranks the car engine easier than a cold one.

The dry solid polymer battery uses heat to promote ion flow in what is called a “true plastic battery.” The battery requires a core temperature of 60 to 100°C (140 to 212°F) to become conductive. The dry solid polymer has found a niche market for stationary power applications in warm climates where heat serves as a catalyst rather than a disadvantage. Built-in heating elements keep the battery operational at all times. High battery cost and safety concerns have limited the application of this technology. The more common Li-polymer uses moist electrolyte to enhance conductivity, as discussed earlier. Read more about the Lithium-polymer battery.

Batteries achieve optimum service life if used at 20°C (68°F) or slightly below, and nickel-based chemistries degrade rapidly when cycled at high ambient temperatures. If, for example, a battery operates at 30°C (86°F) instead of a more moderate room temperature, the cycle life is reduced by 20 percent. At 40°C (104°F), the loss jumps to a whopping 40 percent, and if charged and discharged at 45°C (113°F), the cycle life is only half of what can be expected if used at 20°C (68°F).

The performance of all battery chemistries drops drastically at low temperatures. At –20°C (–4°F) most nickel-, lead- and lithium-based batteries stop functioning. Although NiCd can go down to –40°C (-40°F), the permissible discharge is only 0.2C (5-hour rate). Specially built Li- ion brings the operating temperature down to –40°C, but only on discharge and at a reduced discharge. With lead acid we have the danger of the electrolyte freezing, which can crack the enclosure. Lead acid freezes more easily with a low charge when the specific gravity of the electrolyte is more like water.

Cell matching by using cells of similar capacity plays an important role when discharging at low temperature under heavy load. Since the cells in a battery pack can never be perfectly matched, a negative voltage potential can occur across a weaker cell on a multi-cell pack if the discharge is allowed to continue beyond a safe cut-off point. Known as cell reversal, the weak cell suffers damage to the point of developing a permanent electrical short. The larger the cell-count, the greater the likelihood that a cell might reverse under load. Over-discharge at a heavy load and low temperature is a large contributor to battery failure of cordless power tools, especially nickel-based packs; Li-ion packs come with protection circuits and the failure rate is lower. Read about Cell Mismatch and Balancing.

Users of electric vehicles need to understand that the driving distance specified per charge is given under normal temperature; frigid cold will sharply reduce the available mileage. Using electricity for cabin heating is not the only cause for the shorter driving distance between charging; the battery performance is reduced when cold. 

Comments

On October 31, 2011 at 1:12pm
gohr then wrote:

good article

On February 7, 2012 at 10:43am
Allen Normand wrote:

Looking for engine starting batteries to be used in Dubai area where ambiant temp can get to 52 degrees C and the engine room can get to 60 degree C. Right now we have 4 - 8D batteries per engine X 6 engines (series and parallel for 24VDC) and we are having to change every year or so..
Any suggestions?
Gell cells?
AGM?
New Technology??

On August 7, 2012 at 3:29am
Mehmet TURKER wrote:

Is 18650 li-ion battery can use at -40C? Thanks for informations.

On August 24, 2012 at 2:52am
Stijn wrote:

What is the maximum temperature before a lipo pouch cell is permanently damaged?

On August 30, 2012 at 4:12am
Yenya wrote:

I want to choose battery for my bicycle lights. I ride my bike also in winter (let’s say up to -12 degrees celsius). Which battery type can be used? I don’t need full capacity at that temperature, because in winter I only ride my bike for commuting and not for longer trips, but I would not like to damage the battery in that temperature.

I have found articles that Li-Pol can be damaged by low temperatures. How about LiFePo or others?  I would prefer not to carry lead-acid accumulator on my bike grin

On October 12, 2012 at 5:46am
Ayush Sugandhi wrote:

Great article

On November 17, 2012 at 4:24pm
BackBlast wrote:

Easy way to solve a bike light in cold weather is to keep it on your person or in your pocket until you need it.  The cell(s) will be much higher than ambient and you won’t have any trouble on a short ride.  High output lights will generate enough internal heat to compensate some thereafter, depending on the power consumption, efficiency, airflow, etc…

I believe that damage can occur if you discharge too fast at low temperatures, or attempt a charge at low temperatures with any Lithium variant.

I use LSD NiMH and more recently LiFePO4 for my bike lights, though I’m never riding at -12C.  I’ve been relatively pleased with NiMH low temp performance so far.  Especially with the newest cells when on a low cycle count.

On February 10, 2013 at 1:54pm
relyt wrote:

could any body use this as a science project?

On March 3, 2013 at 2:43pm
EDGAR PARRADO wrote:

Can a new lithium-ion battery be discharged (ruined) if shipped via air with low temperature in cargo bay?

On March 28, 2013 at 11:10pm
Victor wrote:

well, at 27°C the li-ion battery has a maximum performance?

On August 4, 2013 at 2:49pm
Subutay wrote:

what is the max.working temperature for li-ion cell 18650

50 C ? / 80 C or any ?

On October 22, 2013 at 5:51pm
SON wrote:

What is better? Case 1 or Case 2
Case 1. Batteries shall be rated for the minimum ambient temperature of five Deg. C for discharge duty.
Case 2. Batteries shall be rated for the minimum ambient temperature of twenty-five Deg. C for discharge duty.

Thanks you in advance.

On January 8, 2014 at 9:28pm
shaym wrote:

i need a chemical name

      in which chemical react with copper its defuse the tungsten filament or leak the alkaline batterys.

On January 25, 2014 at 2:12am
Sara wrote:

what’s the relation between battery temperature and voltage ?  I mean the equation .

On May 13, 2014 at 10:50pm
mohammed nazeer wrote:

i want to know the name of the chemical which can be coated on copper and the coated chemical which reduce the life of battery or it may discharges the volt. can anyone help me to know about the product

On May 31, 2014 at 12:23am
kunnal kumaar wrote:

I want to know the name of the chemical which can be coated on copper and the coated chemical which reduce the life of battery or it may discharges the volt….pals answer.

On August 19, 2014 at 3:57am
nagaraju wrote:

  in which chemical react with copper its defuse the tungsten filamen