FAQ: How to protect your battery against the summer heat

The dog days of summer are in full swing, which means heat-related car battery issues become far more common. Don’t let the hot temps wreak havoc on your battery.

Our experts offer precautionary steps you can take to prevent common issues that arise when your battery experiences too much heat exposure. Read more below.

What are some common car battery issues that occur if they get too hot?
As lead acid batteries absorb high heat, chemical activity in the battery accelerates. This reduces service life at a rate of 50% for every 18°F (10°C) increase from 77°F (25°C). If a battery has a design life of six years at 77°F (25°C), and the battery spent its life at 95°F (35°C), then its delivered service life would be three years. This dramatic reduction in delivered service life can cause older batteries to suddenly fail in high heat because the accelerated failure rate occurs without warning.

What happens to an Absorbed Glass Mat (AGM) battery in extreme heat?
Lead-calcium AGM batteries are similar to lead-calcium flooded batteries as both have continuous grid corrosion (galvanic corrosion) and this issue is increased due to high heat.  Thin Plate Pure Lead (TPPL) AGM batteries do not have this continuous galvanic grid corrosion and as a result have a 10- to 12-year design life. High heat has much less effect of deteriorating the grids as the grids only have one primary material being pure lead at minimum 99.99%.  Although all lead acid batteries service life is affected by high heat, the 10- to 12-year ODYSSEY® battery design life is twice that of lead-calcium automotive/commercial batteries and will always offer twice the life.

Are there any advantages of using AGM batteries over well cell or gel cell in the summer?
TPPL AGM batteries, such as ODYSSEY® Extreme Series™ batteries, are designed specifically for high temperatures. They can reach up to 176°F (80°C) and not lose internal water, as the battery remains sealed during its operation. Other AGM batteries, due to their lower safety internal pressure relief valves, see higher rates of water evaporation. The loss of water results in a diminished capacity and, thus, a reduced service life.

Wet cell batteries are openly vented to the atmosphere, so high heat accelerates internal water evaporation causing early battery failure.

Gel cell battery technology is not popular in transportation for two reasons. First, gel batteries need to be charged at low current rates and vehicles have large charging systems (alternators) so gel batteries would experience significant over charge.  Secondly, gel batteries performance in severe cold make them near inoperable.  They are not a good engine start battery as a result.

What are a few tips to help maintain batteries in hot weather?
Know the installation date of your existing battery and if it’s wet-flooded, lead-calcium AGM or TPPL AGM.

Vehicles that are driven nearly every day take care of their batteries, meaning there really is no additional maintenance needed.  Vehicles that are occasionally driven; weekend collector cars and RVs need charger/ battery maintainers to keep batteries at full charge, as high heat will dramatically accelerate self-discharge rates, causing low states of charge, developing sulfation that will reduce performance and service life.

What maintenance should you perform on your battery post-summer?
Load testing is the most effective way to inspect your battery to know its status. It is why most vehicle service centers include battery testing as part of their vehicle review.

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