 
Effect of Temperature on Battery Life – Lead-acid batteries are cost-effective and reliable, making them suitable for many applications. One serious drawback compared to some other batteries (NiCad for example), is that lead-acid batteries are affected by temperature. Lead-acid batteries should only be used where they are installed in conditioned environments not subject to excessive temperatures.
Typically the rating for lead-acid batteries is based on an ambient temperature of 25oC. For every 8oC above ambient during use, the life of the battery will be reduced by 50%. Ideally, batteries should be operated at 25oC or less.
In addition to operation, the storage of batteries waiting for use is also affected by temperature. If lead-acid batteries are stored at elevated temperatures (particularly in a discharged condition), they will effectively become useless. If storing batteries, they should be in charged and stored at 25oC or less. Batteries will self-discharge over time and need to be recharged periodically.
Based on a study it can be concluded that the best
operating ambient condition of a battery is 300C. The ambient
temperature above and below this range affect the battery in a
negative way. In order to compensate for the ambient, it can be
recommended that the batteries should be charged at a higher
voltage and C-10 current at low temperatures, and at high
temperatures the charging current should be reduced to 75%
of the rated C-10 current.
How to reduce the effect of Temperature of Battery Life
There a few ways in which this can be managed
- Move the battery away from the engine compartment (Done only by some OEMs)
- Provide a cover for the Battery in the engine bay
- Use the right charger which has inbuilt Temperature compensation
Move the Battery Compartment
We are seeing a number of auto companies now resorting to move the battery form the engine bay to other parts of the car like under the seat or in the boot area. This way they are able to manage the effect of high temperatures in the engine compartment. This is quite an effective way as temperatures in engine bay may reach upto 100 degrees.
The downside is that it can make reaching the battery really difficult or even requiring special tools.
Provide a Heat-Protective cover
This is a relatively easier solution and can be implemented even by the car owner. In the above picture you will notice that companies like Skoda are providing this cover for the battery. This way they are aiming to reduce the effect of temperature on battery life and also reduced dirt effect.
Use a Charger with an inbuilt Temperature Compensation
CTEK MXS 7
