Rick's Free Auto Repair Advice

Optima battery

Should you buy an Optima battery?

An Optima battery is often referred to as a gel cell battery. That’s not true. An Optima battery is actually an absorbed glass matt (AGM) style battery. For the full definition of an AGM battery, see this post. An AGM battery has positive and negative plates like a starting, lighting, ignition (SLI) battery, but uses an absorbent glass matt between the plates to absorb and hold the electrolyte. In other words, the battery acid doesn’t slosh around in an AGM battery as it does in an SLI battery.

An AGM battery can have vertical cells like a standard SLI battery or the cylindrical cells like the Optima battery.

AGM battery

Cylindrical cell versus flat plate technology

Advantages of an Optima battery

An AGM battery delivers more cold cranking amps for starting than a comparably sized SLI battery. They have a larger reserve rating to run your vehicle’s electronics for longer periods when the engine isn’t running. Plus, they can endure more drain/recharge cycles than an SLI battery and last longer than an SLI battery. Finally, they have a lower self-discharge rate than an SLI battery, so they keep their charge longer when not connected to a vehicle.

Other Optima battery advantages

• In addition to the above advantages, an Optima battery is less susceptible to permanent damage from sulfation which occurs when a battery is left in a discharged state for long periods. Leaving the battery in a discharged state for long periods is never recommended, but if you do so on an Optima battery, you’ll have less chance of permanent damage.

• Optima batteries are less resistant to vibration because their cells are tightly wound which reduces plate shedding; common with SLI batteries.

• Optima batteries recharge up to five times faster than SLI batteries because they have less internal resistance than SLI batteries due to their tight packing and close plate-to-electrolyte contact.

• Finally, all AGM batteries are maintenance-free and lose less electrolyte due to recharging. AGM batteries are valve-regulated lead-acid batteries (VRLA). During recharging when the battery produces hydrogen gas, the valve prevents hydrogen gas and water discharge unless pressures overcome the valve set point.

Disadvantages to Optima battery

• Cost— An Optima battery can cost up to 300% more than an SLI battery

An Optima battery requires an AGM compatible charger. Look for the AGM setting on the charger.

• Special recharging equipment — An AGM battery requires a different recharging routine, so the battery charger you use must have an AGM setting. In addition to the AGM setting, some AGM battery chargers have different settings for flat plate versus cylindrical AGM styles.

Types of Optima batteries

Red Top Optima battery

Most starting power of the three types.

Yellow Top Optima Battery

Dual-purpose with great starting power and larger reserve capacity for running electronics with the engine off.

Blue Top Optima Battery

Dual-purpose but built more for marine use or applications where deep power drawdowns are required and where rapid recharging is needed.

©, 2020 Rick Muscoplat

Posted on by Rick Muscoplat


Custom Wordpress Website created by Wizzy Wig Web Design, Minneapolis MN