Optima RedTop 34, 34R, 34/78, Optima YellowTop D34, D34/78 and Optima BlueTop 34M, D34M Batteries Comparison

optima bci group 34 batteries

Optima batteries are very popular automotive and marine battery brand. BCI Group 34 batteries are commonly used as starting, dual purpose and as deep cycle batteries in cars and other vehicles, in boats, off-the-grid applications etc. Optima group 34 batteries come in several, often very similar versions, but optimized for certain applications. Choosing the right one can be daunting task, but it shouldn't.

Optima RedTop, Optima YellowTop and Optima BlueTop Batteries Comparison

There are several way to distinguishes Optima batteries regarding their intended purpose:

- battery casing: Optima batteries with light gray casings are dual purpose batteries and can be used as both starting and deep cycle batteries. As starting batteries, they are not as strong as true starting batteries, but they tolerate deep cycle operations much better. Optima batteries with dark gray casings are true starting batteries and although they can be used in cycling operations too, they should be used as starting batteries, only.

- battery top: Optima RedTop batteries are intended for starting automotive applications, Optima YellowTop are designed for dual purpose automotive applications, while Optima BlueTop batteries are intended for marine applications - Optima BlueTop with light gray casings are marine dual purpose batteries, while Optima BlueTop with dark gray casings are marine starting batteries.

- battery terminals/posts: batteries with SAE or dual SAE/GM terminals are intended for automotive applications, while batteries with dual SAE and 5/16 stainless studs are intended for marine applications.

All Optima RedTop, YellowTop and BlueTop batteries are SLA AGM batteries, very resistant to vibrations and being able to operate in any position. Also, they are very low maintenance batteries.

Also, Optima Group 34 batteries are not the cheapest batteries on the market, but due to their features and quality, they are one of the most popular batteries in this BCI group.

The following table lists the most important features of Optima RedTop, YellowTop and BlueTop group 34 batteries - note that the batteries are ordered according to their SKU number:

Battery Model Photo Battery Type BCI Goup Size Chemistry Terminals/Posts Capacity 20h (Ah) CCA (Amps) MCA (Amps) RC (min) Weight (lbs/kg)
Optima RedTop 8002-002 34 optima redtop 34 battery table Starting 34 AGM SAE 50 800 1000 100 37.9 lbs
17.2 kg
Optima RedTop 8003-151 34R optima redtop 34r battery table Starting 34R AGM SAE 50 800 1000 100 37.9 lbs
17.2 kg
Optima RedTop 8004-003 34/78 optima redtop 34 78 battery table Starting 34/78 AGM Dual SAE/GM 50 800 1000 100 38.8 lbs
17.6 kg
Optima BlueTop 8006-006 34M optima redtop 34m battery table Starting 34 AGM Dual SAE & 5/16 Stainless Stud  50 800 1000 100 38.4 lbs
17.4 kg
Optima YellowTop 8012-021 D34 optima redtop d34 battery t Dual Purpose 34 AGM SAE 55 750 870 120 42.9 lbs
19.5 kg
Optima YellowTop 8014-045 D34/78 optima redtop d34 78 battery table Dual Purpose 34/78 AGM Dual SAE/GM 55 750 870 120 43.5 lbs
19.7 kg
Optima BlueTop 8016-103 D34M optima redtop d34m battery table Dual Purpose 34 AGM Dual SAE & 5/16 Stainless Stud  55 750 870 120 43.5 lbs
19.7 kg

Note: Amazon affiliate links in the table open in the new windows.

Starting Optima BCI Group 34 Batteries

optima redtop 34 battery 1There are four models of starting Optima BCI Group 34 batteries and they all feature the same performances.

Their 20h capacity is rated at 50 Ah, their CCA value is 800 Amps, MCA value is 1000 Amps, and their reserve capacity (RC) is 100 minutes.

These batteries also differ in certain details:

- Optima RedTop 8002-002 34 battery: true starting automotive battery, very resistant to vibrations, long operating life, spill-proof, comes with standard SAE posts, and it weighs 37.9 pounds.

- Optima RedTop 8003-151 34R battery: very similar to Optima RedTop 8002-002 34, just the posts/terminals are reversed.

- Optima RedTop 8004-003 34/78 battery: very similar to Optima RedTop 8002-002 34, except that it has dual SAE/GM posts and it is somewhat heavier (38.8 vs 37.9 pounds).

- Optima BlueTop 8006-006 34M battery: very similar to Optima RedTop 8002-002 34, except that it is designed for marine applications and feature dual SAE and 5/16 stainless studs. It is somewhat heavier than Optima RedTop 8002-002 34, but it is lighter than Optima RedTop 8004-003 34/78 (38.4 vs 37.9 vs 38.8 pounds).

Starting batteries should be used for their intended purpose and for powering lights and similar loads, but the battery should never be discharged below 50% of its capacity, at least not on a regular basis.

Dual Purpose Optima BCI Group 34 Batteries

optima redtop d34m battery 1There are three models of dual purpose Optima BCI Group 34 batteries and they all features the same electrical performances.

Their 20h capacity is rated at 55 Ah, their CCA value is 750 Amps, MCA value is 870 Amps and their RC is 120 minutes. Also, these batteries differ in several important details:

- Optima YellowTop 8012-021 D34 battery: dual purpose automotive battery with good starting and deep cycle characteristics. It is very resistant to vibrations, it is spill-proof, has long operating life, it is almost maintenance free, it comes with SAE posts and weighs 42.9 pounds.

- Optima YellowTop 8014-045 D34/78 battery: it is very similar to Optima YellowTop 8012-021 D34 battery, except that it features dual SAE/GM posts (hence the 'D34/78') and it is slightly heavier (43.5 vs 42.9 pounds).

- Optima BlueTop 8016-103 D34M battery: again, it is very similar to Optima YellowTop 8012-021 D34 battery, except that it is designed for marine applications and features dual SAE and 5/16 stainless studs. It weighs just like Optima YellowTop 8014-045 D34/78 battery (43.5 pounds) and it is slightly heavier than Optima YellowTop 8012-021 D34 battery (43.5 vs 42.9 pounds).

Dual purpose batteries can be used as starting batteries if their cranking currents are large enough, but they can also be used as deep discharge batteries on a regular basis (deep-cycle operations), preferably without being discharged below 70-80% of their capacity.

Note: dual purpose batteries are generally heavier since they have thicker plates, optimized for deep-discharge applications. Optima batteries tolerate deep discharges (below 20%) and can recover from such situations, but if possible, try to avoid them.

Starting vs Dual Purpose Optima BCI Group 34 Batteries

optima redtop d34 battery 1Starting Optima BCI Group 34 batteries have lower 20h capacity (50 vs 55 Ah), they have better CCA rating (800 vs 750 Amps) and better MCA rating (1000 vs 870 Amps).

Also, they have lover RC value (100 vs 120 minutes) and are somewhat lighter (37.9 vs 42.9 pounds - 34 vs d34 models).

 They should be chosen according to their intended purpose:

- car starting battery: go for Optima RedTop battery and pick according the required terminals.

- car dual purpose battery: go for Optima YellowTop battery, just be sure to check which terminals are actually needed.

- marine staring battery: go for Optima BlueTop with dark casing battery (34M model).

- marine dual purpose battery: go for Optima BlueTop with light gray casing battery (D34M model).


Optima BCI Group 34 are very popular AGM batteries due to their features and performances that justify their price.

If you need tough and reliable AGM group 34 battery, consider one of these Optima batteries.