Does temperature and or humidity affect batteries?

Batteries are affected by temperature and or humidity. If batteries are too hot or too cold, then yes batteries will exhibit behaviors that would be incongruent with their normal and designed operating specifications. This is not a manufacturer defect but a consequence of using a battery in an environment that the battery was never designed to be used. Let us refer to this type of environment as a weather extreme.

If a battery is exposed to a weather extreme it may stop working, bulge, bubble, melt, damage your device, smoke, create sparks, create flames, expand, contract, and or even blow-up in very extreme cases.

Weather extremes, where the ambient temperature and the relative humidity of a specific environment are altered beyond the norm may occur almost anywhere and at anytime. Here are a few such examples (this is by no means exhaustive): a weather extreme can occur outside, in a non-temperature controlled room, in a closed bathroom with the shower on, in a closed car on a hot day, in a steam-room or a sauna to name a few places. Altitude also affects batteries, for example above 15,000 feet in non-pressurized cabin. Extreme cold also affects the battery as the internal components expand as direct result to A weather extreme can also occur even when the temperature is well within the range of the devices specification but the relative humidity increases the ambient temperature beyond the norm.

If a device including the battery is exposed to weather extremes for any length of time then there will be an affect; mostly a negative effect on your device and battery.

Why does temperature affect a battery - because batteries are a device that converts chemical energy into electrical energy? A battery is an electro-chemical device. A battery has two electrodes, an anode (the positive end) and a cathode (the negative end). In between the batterys two electrodes runs an electrical current caused primarily from a voltage differential between the anode and cathode. The voltage runs through a chemical called an electrolyte (which can be either liquid or solid). This battery consisting of two electrodes is called a voltaic cell.

The batteries we use today are simple variations of the early battery or voltaic cell. Todays batterys are made up of plates of reactive chemicals separated by barriers, being polarized so all the electrons gather on one side. The side that all the electrons gather on becomes negatively charged, and the other side becomes positively charged. Connecting a device creates a current and the electrons flow through the device to the positive side. At the same time, an electrochemical reaction takes place inside the batteries to replenish the electrons. The effect is a chemical process that creates electrical energy.

When ambient temperature changes occur the electrons within the battery is affected. When an increase in temperature occurs the electrons are excited. A decrease in temperature inhibits electrons. This is a natural reaction on electrons in most systems. Furthermore, the combination of a rapid temperature change and high humidity can cause condensation to form and a potential hazard for your battery and device for that matter.