Optima 8052-161 D31M BlueTop Dual Purpose Marine Battery

Optima 8052-161 D31M BlueTop Dual Purpose Marine Battery is very popular starting and deep cycle battery for marine and automotive applications. It is maintenance free and spill-proof SLA battery that can operate in virtually any position, featuring very good both starting and deep cycle performances. It is commonly used in single battery electrical systems found at RVs, boats, yachts, and even cars.

optima 8052 161 d31m

Optima D31M Features and Specifications

Battery plates are made out of high purity lead-tin alloy. Six wound cell configuration utilize so-called Optima's SpiralCell technology.

Optima D31M is dual purpose (hence the 'D'), BCI group 31 (hence the '31') battery, designed for marine (hence the 'M') applications. It features Dual SAE and 5/16 Stainless Stud terminals, allowing the battery to be used in both marine and automotive applications.

Optima D31M physical dimensions are (W x L x H) 6.56 x 12.81 x 9.38 inches (~16.7 x 32.5 x 23.8 cm) and it weighs 59.8 pounds (~27.1 kg).

Nominal capacity (20h) of the battery is 75 Ah, with an RC value of 155 minutes.

Also, its CCA is 900 Amps and MCA value is 1125 Amps.

Optima D31M is designed to be recharged using standard charging methods, for example using alternator, battery charger, float charger and similar.

Also, it can be recharged quickly, to the maximum voltage of 15.6 volts, practically with no current limit, as long as the battery temperature stays below 125°F (51.7°C).

For example, Optima D31M discharged down to 10.5 volts can be rapidly recharged to 90% of charge using:

- 100 Amps current for 52 minutes,

- 50 Amps current for 112 minutes,

- 25 Amps current for 210 minutes.

Fast charging is very important for cycling applications, like in electric vehicles, trolling motor batteries and similar.

Note: don't overcharge SLA AGM/Gel Cell batteries - when safety valves open, excess hydrogen and oxygen escape the casing and they can't be replaced. Also, escaping gases are flammable - thus, always charge your batteries using voltage regulated chargers!

Optima D31M vs. Other Group 31 Batteries

 battleborn lithium 300pxexide xmc 31 modyssey 31m pc2150st m battery moptima 8052 161 d31m m

  Following table lists the most popular BCI group 31 batteries, with their most important features:

Model Battery Type Goup Size Cell Type Capacity MCA RC Weight (lbs/kg)
Battle Born 100Ah 12V LiFePO4 Battery Deep Cycle 31 LiFePO4 100 - - 29 lbs; 13.2 kg
Exide XMC-31 Dual Purpose 31 AGM 100 1110 200 68 lbs; 31 kg
Lifeline GPL-31T Deep Cycle 31 AGM 105 750 195 69 lbs;  31.5 kg
Odyssey 31M-PC2150 Dual Purpose 31 AGM 100 1370 205 77.8 lbs; 35.3 kg 
Optima 8052-161 D31M Dual Purpose 31 AGM 75 1125 155 59.8 lbs; 27.1 kg
Trojan T31 Deep Cycle 31 AGM 102 720 177 69 lbs; 31.5 kg
VMAXTANKS SLR125 Deep Cycle 31 AGM 125 - 260 75 lbs; 34 kg
VMAXTANKS MR137-120 Deep Cycle 31 AGM 120 900 230 75 lbs; 34 kg

Note: Amazon affiliate links in the table open in the new windows, feel free to check them out. Also, the table lists MCA values and not CCA values of the batteries.

As one can see, Optima D31M is one of the lightest BCI group AGM batteries. Battle Born 100Ah 12V LiFePO4 Battery is much lighter battery, but it is lithium, not lead-acid battery.

Due to the spiral cells, cells internally are densely packed, but Optima D31M is not as compact as other batteries. For example, when being compared with other group 31 batteries:

- Optima D31M (dual purpose) relative 20h capacity is 1.254 Ah/lbs, RC 2.59 A/lbs, MCA 18.81 A/lbs,

- Exide XMC-31 (dual purpose) relative capacity is 1.47 Ah/lbs, RC 2.94 A/lbs, MCA 16.32 A/lbs,

- Odyssey 31M-PC2150 (dual purpose) relative 20h capacity is 1.285 Ah/lbs, RC 2.63 A/lbs, MCA 17.6 A/lbs,

- VMAXTANKS MR137-120 (deep cycle) relative 20h capacity is impressive 1.6 Ah/lbs, RC 3.06 A/lbs, MCA 12 A/lbs.

As one can see, Optima D31M is 'dual purpose' battery with very good starting characteristics.

Note that Exide XMC-31 is considered as deep cycle battery by the manufacturer, but it has also very good starting characteristics, and is thus often used as dual purpose battery.

optima 8052 161 d31m 2

 Optima D31M vs. Other 800+ CCA Batteries

The following table lists the most popular AGM car, truck, RV and marine 1000 CCA/MCA/HCA batteries, with their most important features:

Model Battery Type Goup Size Capacity (Ah) CCA (Amps) Relative CCA
(Amps/lbs)
RC (min) Weight (lbs/kg)
DieHard 38217 Deep Cycle 49 92 850 14.5 170 58.5 lbs; 26.5 kg
Exide XMC-31 Dual Purpose 31 100 925 13.6 200 68 lbs; 31 kg
Odyssey 31M-PC2150ST-M Dual Purpose 31 100 1150 14.8 205 77.8 lbs; 35.3 kg 
Odyssey 34M-PC1500ST Dual Purpose 34 68 850 17.2 135 49.5 lbs; 22.4 kg
Optima 8002-002 34 Starting 34 50 800  21.1 100 37.9 lbs; 17.2 kg
Optima 8006-006 34M Starting 34 50 800  20.8 100 38.4 lbs; 17.4 kg
Optima 8027-127 D27M Dual Purpose 27 66 800  14.8 140 54 lbs; 24.5 kg
Optima 8037-127 D27F Dual Purpose 27 66 830  15.6 140 53.2 lbs; 24.1 kg
Optima 8052-161 D31M Dual Purpose 31 75 900  15.1 155 59.8 lbs; 27.1 kg

Note: Amazon affiliate links in the table open in the new windows, feel free to check them for the latest offers.

When being compared with smaller AGM starting batteries (>20 Amps/lbs relative CCA), Optima D31M is under-performer (15.1 Amps/lbs relative CCA).

However, when being compared with dual purpose batteries, especially those being able to provide 900+ CCA Amps, it is one of the best batteries in terms of both CCA (900 Amps) and relative CCA (15.1 Amps/lbs).


Long Story Short: Optima D31M is strong, sturdy and reliable daul purpose battery, designed for both marine and automotive applications. As dual purpose battery, it has very good deep cycle and excellent starting capabilities, with very respectful 900 CCA and 1125 MCA.

If you need dual purpose BCI group 31 battery, consider Optima D31M as one of the possible choices.

For more reviews and recommendations, check Optima 8052-161 D31M BlueTop Battery Amazon link (link opens in the new window).