Optima 8052-161 D31M BlueTop Dual Purpose Marine Battery
Optima 8052-161 D31M BlueTop Dual Purpose Marine Battery is a very popular starting and deep cycle battery for marine and automotive applications.
It is a maintenance-free and spill-proof SLA (Sealed Lead-Acid) AGM (Absorbent Glass Mat) 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.
Updated: December 29, 2021.
On This Page:
- Optima D31M Features and Specifications
- Optima D31M vs. Other Group 31 Batteries
- Optima D31M vs. Other 800+ CCA Batteries
- Optima D31M BlueTop as Trolling Motor Battery
- Optima D31M Battery Frequently Asked Questions (FAQ)
Optima D31M Features and Specifications
Battery plates are made out of high purity lead-tin alloy. Six wound cell configuration utilize the so-called Optima's SpiralCell technology.
Optima D31M is dual-purpose (hence the 'D'), BCI group 31 battery (hence the '31'), 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).
The nominal capacity (20h) of the battery is 75 Ah, with an RC (Reserve Capacity) value of 155 minutes.
Also, its CCA (Cold Cranking Amps) rating is 900 Amps and its MCA (Marine Cranking Amps) rating is 1125 Amps.
Optima D31M is designed to be recharged using standard charging methods, for example using the 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!
Personally, if the Optima D31M BlueTop is connected to the electric system of the boat, RV, car, truck, or similar, let the onboard alternator keep the battery charged.
If the battery is being charged on the workbench, advanced AGM battery chargers in the range of 10 to 20 Amps are recommended.
Such battery chargers are programmed to analyze the battery first and then to recharge the battery according to the battery condition.
Such battery chargers allow the user to set the battery type (AGM, Gel-Cell, wet/flooded, etc.), battery usage (cycling or standby), and also feature a temperature probe for more accurate charging during cold and hot days.
Optima D31M vs. Other Group 31 Batteries
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The following table lists the most popular BCI group 31 batteries, with their most important features:
| Model | Battery Type | Group 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 31 AGM batteries. Battle Born 100Ah 12V LiFePO4 Battery is much lighter battery, but it is lithium, not a lead-acid battery, and is intended only for deep-cycle applications.
Due to the spiral cells, cells internally are densely packed, but overall, 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 a 'dual purpose' battery with very good starting characteristics.
Note that Exide XMC-31 is considered as a deep cycle battery by the manufacturer, but it has also very good starting characteristics and is thus often used as a dual-purpose battery.
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 | Group 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 an 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).
Optima D31M BlueTop as Trolling Motor Battery
Optima D31M BlueTop battery is commonly used as a deep cycle trolling motor battery in kayaks, pontoons, and smaller boats.
With its Reserve Capacity (RC) rating of 155 minutes, Optima D31M BlueTop is able to power a 12V 25A trolling motor for ~2 and half hours, which is a very good result for a lead-acid battery weighing ~60 pounds.
Since 50-60 lbs trolling motors require up to 50-55 Amps, Optima D31M BlueTop can easily provide strong enough currents for trolling at the full throttle.
However, if You plan on using your 50-60 lbs trolling motor at full throttle most of the time, first consider getting a strong trolling motor since that 50-60 lbs trolling motor is obviously seriously underpowered, and then consider getting a larger AGM/Gel-Cell lead-acid or even lithium trolling motor battery.
But, if You need a dual-purpose or deep-cycle trolling motor battery that is mostly discharged with currents in the 20-30 Amps range, but it also must be able to provide stronger currents for shorter periods of time, consider Optima D31M BlueTop battery.
Optima D31M Battery Frequently Asked Questions (FAQ)
Here are some of the most common Frequently Asked Questions about Optima D31M battery and Optima batteries in general:
What's the difference between Optima RedTop, YellowTop, and BlueTop batteries?
Optima RedTop, YellowTop, and BlueTop are AGM batteries intended for different use:
- Optima RedTop is starting automotive AGM battery,
- Optima YellowTop is a dual-purpose automotive AGM battery,
- Optima BlueTop is a dual-purpose automotive and marine AGM battery and it has dual battery terminals.
What kind of battery is an Optima BlueTop?
Optima BlueTop is a dual-purpose automotive and marine AGM battery that has dual battery terminals. It is designed to provide strong starting currents and to withstand deep cycle applications.
Is Optima YellowTop worth it?
Optima RedTop, YellowTop, and BlueTop are not the cheapest batteries on the market, but they feature increased vibration resistance, robust cell design, and offer very good charging/discharging characteristics.
How long does an Optima BlueTop last?
It depends on the usage type, charging conditions, vibrations, mechanical impacts, temperature, and similar. Optima BlueTop is designed to last and it will last longer than the average battery, but even the most quality batteries have limits - for short, don't misuse them!
How do I know if my battery is AGM?
It should be written on the battery itself. Also, if the battery lacks water filling holes on top of the battery, the battery is not wet/flooded and can be AGM or Gel-Cell battery.
Are OPTIMA batteries Gel or AGM?
Optima D31M BlueTop is an AGM battery.
Can Optima batteries be recharged?
Yes, and they accept the charge rather quickly as long as their temperature is kept low.
Can you charge an Optima battery with a regular battery charger?
Yes, but advanced AGM battery chargers are recommended.
Which Optima battery is better RedTop or YellowTop?
Since the Optima RedTop is starting automotive AGM battery, and the Optima YellowTop is a dual-purpose automotive AGM battery, choose according to your own needs and requirements.
Long Story Short: Optima D31M is a strong, sturdy, and reliable dual-purpose battery, designed for both marine and automotive applications.
As a dual-purpose battery, it has a very good deep cycle and excellent starting capabilities, with very respectful 900 CCA and 1125 MCA.
If you need a 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
