Battery Equivalents and Replacements

Odyssey 31M-PC2150 AGM Marine Dual Purpose Battery Review and Recommendation

Odyssey 31M-PC2150 is a BCI group 31 battery, designed as a dual-purpose battery. As starting battery it can easily provide 1000+ CCAs and as a deep cycle battery it comes with a 205 min RC rating.

Odyssey 31M-PC2150 is an AGM SLA battery, featuring increased resistance to vibrations, spill-proof design, two types of terminals, can operate in any position, etc.

It is one of the heaviest group 31 batteries on the market and far from being cheap, but it is one of the best batteries in its class (if not the best) and worth every (euro)cent.

odyssey 31m pc2150st m battery
odyssey 31m pc2150st m battery m

Odyssey 31M-PC2150 Features and Specifications

Technical specifications of the Odyssey 31M-PC2150 battery are given in the following table:

Nominal Voltage CCA MCA HCA PHCA 10h Capacity 20h Capacity RC Terminals
12 V 1150 1370 1545 2150 92 Ah 100 Ah 205 min SAE and 3/8” Stud (Pos.); 5/16” Stud (Neg.)
Nominal Voltage CCA
MCA
HCA
PHCA
10h Capacity
20h Capacity
RC
Terminals
12 V 1150
1370
1545
2150
92 Ah
100Ah
205 min
SAE and 3/8” Stud (Pos.); 5/16” Stud (Neg.)

Its physical dimensions are 13 x 6.8 x 9.41 inches (330.2 x 172.7 x 239.0 mm) and it weighs 77.8 lbs (35.3 kg).

Odyssey 31M-PC2150 is Absorbed Glass Mat (AGM) battery - it features a non-spillable electrolyte and it can operate in any position.

Like a typical marine battery, Odyssey 31M-CP2150 features double terminals: SAE and 3/8” Stud (positive), 5/16” Stud (negative).

Odyssey 31M-PC2150 has a very low self-discharge rate - a fully charged battery can be stored for up to two years at 77ºF (25ºC) or until its voltage drops below 12V (whatever happens first). The self-discharge rate depends on the storage temperature and is given in the following table:

Storage Temperature 41°F (5°C) 59°F (15°C) 77°F (25°C) 95°F (35°C) 113°F (45°C)
Storage Time 48 months 36 months 24 months 12 months 6 months

So, after 24 months at 77°F (25°C), fully charged battery voltage will drop down to around 12V and that battery must be charged again.

When the battery leaves the factory, it is shipped in the fully charged state and its voltage is 12.84V (or slightly higher) indicating 100% SOC (state of charge). Over time, the voltage drops slowly - if the battery OCV (Open Circuit Voltage) is over 12.65V, the battery can be installed and used as fully charged.

If the voltage is 12V or less (~35% SOC), the battery should be considered discharged and it must be charged prior to first use.

OCV depends on the SOC and that dependency is given in the following table:

SOC 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
OCV 11.70 V ~11.82 V ~11.95 V ~12.08 V ~12.20 ~12.32 V ~12.46 V ~12.58 V ~12.70 >12.84 V
SOC 10% 30% 50% 70% 80% 90% 100%
OCV 11.70 V ~11.95 V ~12.20 ~12.46 V ~12.58 V ~12.70 >12.84 V

Knowing OCV is important in avoiding deep discharge conditions and prolonging the battery operating life.

Odyssey 31-PC2150 Dual Purpose Battery Versions

Odyssey 31-PC2150 is manufactured in several versions, with each version being optimized for specific use.

odyssey 31 pc2150 versions

The main difference between these batteries are the type and orientation of battery terminals:

- Odyssey 31-PC2150 comes in two versions, having 3/8" Stud or SAE battery terminals. Often, these batteries are labeled as 'Odyssey 31-PC2150T Heavy Duty Commercial Battery' or 'Odyssey 31-PC2150S Heavy Duty Commercial Battery' and indeed, they are batteries for heavy-duty commercial use.

- Odyssey 31M-PC2150 features SAE and 3/8” Stud (positive) 5/16” Stud (negative) battery terminals. This battery is often labeled as 'Odyssey 31M-PC2150ST-M TROLLING Thunder Marine Dual Purpose Battery' since it can be used as both starting marine battery, but also as a deep cycle marine battery, including trolling fishing.

- Odyssey 31R-PC2150 is just like Odyssey 31-PC2150, it just has terminal polarities reversed left and right.

Note: all versions of 31-PC2150 batteries have the same electrical performances (capacity, RC, CCA, MCA, etc).

Extreme Deep Discharge Recovery

Odyssey 31M-PC2150 battery can be recovered from deep discharge state (down to almost 0% of remaining charge), however, such events should be avoided as much as possible.

If something like that happens to the new battery, one should charge the battery to at least 13.5V, preferably to 14.4V, allowing the battery to recover at least 97% of its nominal capacity.

Again, if possible avoid such deep discharge events.

Odyssey 31M-PC2150 AGM as Starting Battery

Battery's plates are made using 99.99% pure lead, and they are densely packed providing good starting power.

The new, fully charged battery can provide 2150 Amps for 5 seconds - this is its PHCA (Pulse Hot Cranking Amps) rating, thus '2150' is part of the battery's label.

HCA (Hot Cranking Amps; 80°F, 27°C) rating is 1545 Amps, MCA (Marine Cranking Amps; 32°F, 0°C) rating is 1370 Amps and IMHO, the most important CCA (Cold Cranking Amps; 0°F, -18°C) rating is 1150 Amps.

Odyssey 31M-PC2150 battery provides 1000+ CCA and it is more than strong enough for most automotive and marine cranking applications and highly recommended model for dual purpose applications as part of single battery (or single battery pack) electrical systems commonly found in the cars, RVs, boats, yachts, etc. where both good starting power and deep cycle performances are required.

odyssey 31m pc2150st m battery 2

Extreme Cold Temperature Starting Performances

One of the important features of the Odyssey 31M-PC2150 battery (and other 21-PC2150 batteries) is its very good performance during extremely cold temperatures.

As said before, its CCA (Cold Cranking Amps; 0°F, -18°C) rating is 1150 Amps and as the temperature is increased, so are its cranking amps (maximum current for 30 seconds, without the voltage dropping below 7.2 V).

However, Odyssey 31M-PC2150 is designed to operate safely down to -40°F (-40°C) and that is rather cold, to say the least.

Under these temperatures (-40°F, -40°C!), Odyssey 31M-PC2150 is able to provide 550 cranking amps for 30 seconds, without its voltage drops below 7.2 V - actually, according to the manufacturer, brand new, fully charged and cooled down to -40°F (-40°C) Odyssey 31M-PC2150 battery can provide 550 Amps for ~34 seconds.

Such cold temperature tolerances and performances mean that during the winter battery can be left on the boat, yacht, RV, or at any similar location without safety or reliability issues. If you do expect local temperatures to be lower than -40°F, it is recommended to remove the battery during such an extremely cold period and store it in the warm(er) area - important note for Alaska, Canada, or Siberia! :)

Odyssey 31M-PC2150 AGM as Deep Cycle Marine Battery

Although battery plates are relatively thin (to provide high currents), they are designed to withstand many charging-discharging cycles. For example, the battery can withstand around 400 charge-discharge cycles down to 80% of maximum discharge (80% DoD - Depth of Discharge, 20% charge left).

However, avoiding really deep discharges can significantly prolong the battery's operating life, as shown in the following table:

DoD% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Number of Cycles ~6000 ~2200 ~1300 ~900 ~650 ~550 ~470 400 ~380 ~320
DoD% 30% 40% 50% 60% 70% 80% 90% 100%
Number of Cycles ~1300 ~900 ~650 ~550 ~470 400 ~380 ~320

Note: the battery is considered good as long as its native 20h capacity is more than 80% of the 20h capacity of the new battery. That means that when 31M-PC2150 battery 20h capacity drops down to 80 Ah or less, the battery is not considered to be good and should be properly recycled!

Although the nominal capacity of the battery is 100 Ah when the fully charged battery is being discharged down to 10.05 V (note: 10.05 V, not the 10.5 V) using constant current at 77°F (25°C), its capacity depends on the current and discharge time and are given in the following table:

Time Watts (W) Amps (A) Capacity (Ah) Energy (Wh)
2 min 7025 678.5 22.4 231.8
5 min 4740 438.5  36.4  393.4
10 min 3176  285.9  47.7  530.4
15 min 2428  215.5  53.9  607.0
20 min 1980  174.1  58.0  659.2 
30 min 1460  127.0  63.5  730.0 
45 min 1059  91.2  68.4  793.9 
1 hr 835  71.5  71.5  835.2 
2 hr 461  39.0  78.0  922.2 
3 hr 322  27.1  81.4  966.8 
4 hr 249  20.9  83.8  996.8 
5 hr 204  17.1  85.6  1020.0 
8 hr 134 11.2  89.7  1070.4 
10 hr 110  9.2  91.9  1095.9 
20 hr 60  5.0  100.3  1191.9 

It is normal for all lead-acid batteries to lose capacity as they are being discharged using strong currents and Odyssey 31M-PC2150 is no exception. However, as the discharging current increases, its capacity drops, but it is still one of the best performers in its class.

If you have a 50-60 pounds electric trolling motor that draws some 50-60 Amps at maximum power, in the worst-case scenario, one can expect one hour of operation (plus some 10-15 minutes for safety). And since many fishermen don't use trolling motors at full power when fishing, one can expect 2-4 hours of operation on half a throttle of such electric trolling motor (time depends on the battery condition, weather conditions, actual trolling pace, etc).

When charging 31-PC2150 battery used for cycling applications, it is important to use battery chargers that can deliver at least 0.4C strong currents in the bulk charge mode and that can charge the battery up to 14.7 V.

Odyssey 31M-PC2150 vs. Other Group 31 Batteries

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

Model Battery Type Cell Type Ah CCA MCA RC Weight (lbs/kg)
AIMS Power LFP12V100A Deep Cycle LiFePO4  100 - - ~240 30.2 lbs; 13.7 kg
Battle Born 100Ah 12V LiFePO4 Deep Cycle LiFePO4 100 - - ~240 29 lbs; 13.2 kg
Exide XMC-31 Deep Cycle AGM 100 925 1110 200 68 lbs; 31 kg
ExpertPower EP12100 Deep Cycle LiFePO4  100 - - ~240 29.7 lbs; 13.5 kg
GreenLiFE Battery GL100 Dual Purpose LiFePO4 100 - - 240 28 lbs; 12.7 kg
Lifeline GPL-31T Deep Cycle AGM 105 600 750 195 69 lbs; 31.5 kg
Lifeline GPL-31XT Deep Cycle AGM 125 650 800 230 69 lbs; 31.5 kg
Lifeline GPL-3100T Dual Purpose AGM 100 810 950 228 67 lbs; 30.4 kg
Mighty Max ML100-12 DS-IGEL Deep Cycle Gel 100 - - 180+ 68.2 lbs; 30.9 kg
NorthStar ELT-AGM31 Dual Purpose AGM 100 925 1050 190 65.7 lbs; 29.8 kg
NorthStar NSB-AGM31 Dual Purpose AGM 103 1150 1370 220 75 lbs; 34.0 kg
NorthStar NSB-AGM31M Dual Purpose AGM 103 1150 1370 220 75 lbs; 34.0 kg 
Odyssey 31-PC2150S Dual Purpose AGM 100 1150 1370 205 77.8 lbs; 35.3 kg 
Optima 8052-161 D31M Dual Purpose AGM 75 900 1125 155 59.8 lbs; 27.1 kg
Renogy RNG-BATT-AGM12-100 Deep Cycle AGM 104 - - 180+ 66 lbs; 29.9 kg
Renogy RNG-BATT-GEL12-100 Deep Cycle Gel 100 - - 180+ 60 lbs; 27.2 kg
Renogy RBT100GEL12-G1 Deep Cycle Gel 100 - - ~175 63.9 lbs; 29 kg
Trojan T31-AGM Deep Cycle Gel 102 - - 200 70 lbs; 31.7 kg
VMAXTANKS SLR125 Deep Cycle AGM 125 - - 260 75 lbs; 34 kg
VMAXTANKS MR137-120 Deep Cycle AGM 120 - 900 230 75 lbs; 34 kg
VMAXTANKS VPG12C-100LFP Deep Cycle LiFePO4 100 - - ~240 26.4 lbs; ~12.0 kg
VMAXTANKS XTR31-135 Deep Cycle AGM 135 730 920 265 77 lbs; 34.9 kg
XS Power XP3000 Deep Cycle AGM 120 - - 240 73 lbs;  33.1 kg
Weize 12V 100Ah AGM Deep Cycle AGM 100 - - - 60 pounds; 27.2 kg
Weize 12V 100Ah Gel Deep Cycle Gel 100 - - <180 67 pounds; 30.4 kg
WindyNation BAT-NSAP12-100 Deep Cycle AGM 106 - - 180+ 67 lbs; 30.4 kg
Model

Battery Type


Battery Chemistry

Ah


RC

CCA


MCA

Weight (lbs/kg)
AIMS Power LFP12V100A

Deep Cycle


LiFePO4

100


~240

-


-

30.2 lbs; 13.7 kg
Battle Born 100Ah 12V LiFePO4

Deep Cycle


LiFePO4

100


~240

-


-

29 lbs; 13.2 kg
Exide XMC-31

Deep Cycle


AGM

100


200

925


1110

68 lbs; 31 kg
ExpertPower EP12100

Deep Cycle


LiFePO4

100


~240

-


-

29.7 lbs; 13.5 kg
GreenLiFE Battery GL100

Dual Purpose


LiFePO4

100


240

-


-

28 lbs; 12.7 kg
Lifeline GPL-31T

Deep Cycle


AGM

105


195

600


750

69 lbs;  31.5 kg
Lifeline GPL-31XT

Deep Cycle


AGM

125


230

650


800

69 lbs; 31.5 kg
Lifeline GPL-3100T

Dual Purpose


AGM

100


228

810


950

67 lbs; 30.4 kg
Mighty Max ML100-12 DS-IGEL

Deep Cycle


Gel

100


180+

-


-

68.2 lbs; 30.9 kg 
NorthStar ELT-AGM31

Dual Purpose


AGM

100


190

925


1050

65.7 lbs; 29.8 kg
NorthStar NSB-AGM31

Dual Purpose


AGM

103


220

1150


1370

75 lbs; 34.0 kg
NorthStar NSB-AGM31M

Dual Purpose


AGM

103


220

1150


1370

75 lbs; 34.0 kg 
Odyssey 31-PC2150S

Dual Purpose


AGM

100


205

1150


1370

77.8 lbs; 35.3 kg 
Optima 8052-161 D31M

Dual Purpose


AGM

75


155

900


1125

59.8 lbs; 27.1 kg
Renogy RNG-BATT-AGM12-100

Deep Cycle


AGM

104


180+

-


-

66 lbs; 29.9 kg
Renogy RNG-BATT-GEL12-100

Deep Cycle


Gel-Cell

100


180+

-


-

60 lbs; 27.2 kg
Renogy RBT100GEL12-G1

Deep Cycle


Gel-Cell

100


~175

-


-

63.9 lbs; 29 kg
Trojan T31-AGM

Deep Cycle


Gel-Cell

102


200

-


-

70 lbs; 31.7 kg
VMAXTANKS SLR125

Deep Cycle


AGM

125


260

-


-

75 lbs; 34 kg
VMAXTANKS MR137-120

Deep Cycle


AGM

120


230

-


900

75 lbs; 34 kg
VMAXTANKS VPG12C-100LFP

Deep Cycle


LiFePO4

100


~240

-


-

26.4 lbs; ~12.0 kg
VMAXTANKS XTR31-135

Deep Cycle


AGM

135


265

730


920

77 lbs; 34.9 kg
XS Power XP3000

Deep Cycle


AGM

120


240

-


-

73 lbs;  33.1 kg
Weize 12V 100Ah AGM

Deep Cycle


AGM

100


-

-


-

60 pounds; 27.2 kg
Weize 12V 100Ah Gel

Deep Cycle


Gel-Cell

100


<180

-


-

67 pounds; 30.4 kg
WindyNation BAT-NSAP12-100

Deep Cycle


AGM

106


180+

-


-

67 lbs; 30.4 kg

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

All of the batteries in the table are lead-acid AGM batteries except Battle Born 100Ah LiFePO4 deep cycle battery, which is an excellent deep cycle battery designed for various applications, except starting applications (it can deliver 100 Amps continuously, and 200 Amps for 30 seconds).

Also, it is a very lightweight battery, being almost 3x lighter than the Odyssey 31M-PC2150 battery. But, the Battle Born 100Ah LiFePO4 deep cycle battery is also a very expensive battery.

When 31-PC2150 batteries are compared with another group 31 AGM batteries, one can conclude:

- group 31 AGM batteries are heavy, and the 31-PC2150 is one of the heaviest in this class,

- high-quality deep cycle group 31 batteries have somewhat better 20h capacity and RC rating than the 31-PC2150 battery,

- common deep cycle group 31 AGM batteries have capacity and RC rating similar to the 31-PC2150 dual purpose battery.

- other dual-purpose group 31 AGM batteries are lighter and have a lower CCA/MCA rating than the 31-PC2150 battery.

Personally, in this group, only Exide XMC-31 comes close to the 31-PC2150 battery. However, also note that Exide XMC-31 is almost 10 pounds lighter battery.

If you need a good 31 group AGM battery and don't have weight issues, go for Odyssey 31M-PC2150 battery.

Odyssey 31M-PC2150 vs. Other 1000+ CCA Batteries

To be able to provide 1000+ CCAs is a very tough requirement for any type of marine or automotive battery.

Many batteries can provide 1000+ MCAs and especially 1000+ HCAs, but as the temperature drops, so does the cranking amps.

The following table lists marine/automotive batteries which are able to provide at least 800 CCAs:

Model Battery Type Group Size Ah CCA RC Weight (lbs/kg)
ACDelco 49AGM Dual Purpose 49 95 900 160 -
Bosch S6588B S6 Dual Purpose 49 92 850 160 -
DieHard 38217 Deep Cycle 49 92 850 170 58.5 lbs; 26.5 kg
Exide XMC-31 Deep Cycle 31 100 925 200 68 lbs; 30.8 kg
NorthStar NSB-AGM27M Dual Purpose 27 92 930 195 68 lbs; 30.8 kg
NorthStar NSB-AGM31M Dual Purpose 31 103 1150 220 75 lbs; 34.0 kg
Odyssey 31M-PC2150ST-M Dual Purpose 31 100 1150 205 77.8 lbs; 35.3 kg 
Odyssey 34M-PC1500ST Dual Purpose 34 68 850 135 49.5 lbs; 22.4 kg
Odyssey PC1800-FT Deep Cycle - 214 1300 475 132.3 lbs; 60.0 kg
Odyssey PC2250 Dual Purpose - 126 1225 240 86.0 lbs; 39.0 kg
Optima 8002-002 34 Starting 34 50 800 100 37.9 lbs; 17.2 kg
Optima 8006-006 34M Starting 34 50 800 100 38.4 lbs; 17.4 kg
Optima 8027-127 D27M Dual Purpose 27 66 800 140 54 lbs; 24.5 kg
Optima 8037-127 D27F Dual Purpose 27 66 830 140 53.2 lbs; 24.1 kg
Optima 8052-161 D31M Dual Purpose 31 75 900 155 59.8 lbs; 27.1 kg
Vmaxtanks VMAX MR197 Deep Cycle 4D 200 1120 450 112 lbs; 50.7 kg
Vmaxtanks VMAX XTR4D-200 Deep Cycle 4D 200 1250 470 130 lbs; 58.9 kg
Vmaxtanks VMAX XTR8D-350 Deep Cycle 8D 350 1700 780 185 lbs; 83.8 kg
Model

Battery Type


Group Size

Ah


RC

CCA Weight (lbs/kg)
ACDelco 49AGM

Dual Purpose


49

95


160

900 -
Bosch S6588B S6

Dual Purpose


49

92


160

850 -
DieHard 38217

Deep Cycle


49

92


170

850 58.5 lbs; 26.5 kg
Exide XMC-31

Deep Cycle


31

100


200

925 68 lbs; 30.8 kg
NorthStar NSB-AGM27M

Dual Purpose


27

92


195

930 68 lbs; 30.8 kg
NorthStar NSB-AGM31M

Dual Purpose


31

103


220

1150 75 lbs; 34.0 kg
Odyssey 31M-PC2150ST-M

Dual Purpose


31

100


205

1150 77.8 lbs; 35.3 kg 
Odyssey 34M-PC1500ST

Dual Purpose


34

68


135

850 49.5 lbs; 22.4 kg
Odyssey PC1800-FT

Deep Cycle


-

214


475

1300 132.3 lbs; 60.0 kg
Odyssey PC2250

Dual Purpose


-

126


240

1225 86.0 lbs; 39.0 kg
Optima 8002-002 34

Starting


34

50


100

800 37.9 lbs; 17.2 kg
Optima 8006-006 34M

Starting


34

50


100

800 38.4 lbs; 17.4 kg
Optima 8027-127 D27M

Dual Purpose


27

66


140

800 54 lbs; 24.5 kg
Optima 8037-127 D27F

Dual Purpose


27

66


140

830 53.2 lbs; 24.1 kg
Optima 8052-161 D31M

Dual Purpose


31

75


155

900 59.8 lbs; 27.1 kg
Vmaxtanks VMAX MR197

Deep Cycle


4D

200


450

1120 112 lbs; 50.7 kg
Vmaxtanks VMAX XTR4D-200

Deep Cycle


4D

200


470

1250 130 lbs; 58.9 kg
Vmaxtanks VMAX XTR8D-350

Deep Cycle


8D

350


780

1700 185 lbs; 83.8 kg

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

Large deep AGM deep cycle batteries with a capacity of 200+ Ah are generally able to provide 1000+ CCAs. They are large, heavy, and store plenty of energy and although designed for cycling applications, they are obviously strong enough even for 1000+ CCA applications.

On the other hand, dual-purpose batteries weighing 65 to 85 pounds are generally able to provide 1000 CCAs (or almost 1000 CCAs).

Odyssey PC2250 is clearly the winner in 1000+ CCAs dual-purpose battery class, at least regarding performances. However, it is also some 8 pounds heavier than PC2150 battery and 18 pounds(!) heavier than Exide XMC-31.

Again, when looking for the 1000+ CCA battery, Odyssey 31M-PC2150 is perhaps the best-balanced battery.

For more about these batteries, check our Pick the Best 1000 CCA (Cold Cranking Amps) Marine Battery article.


odyssey 31m pc2150st m battery mFor Short: Odyssey 31M-PC2150 battery is not cheap and also not lightweight SLA AGM battery.

But, it is also one of the best-balanced designs, very reliable in broad temperature range, with excellent electrical characteristics. It is worth its price, IMHO of course.

For more reviews and recommendations, check Odyssey 31M-PC2150 Marine Dual Purpose Battery Amazon link (link opens in the new window).

Amazon Search - Check the Prices:

- Odyssey AGM Battery

- Odyssey 31M-PC2150 Marine Dual Purpose Battery

- Group 31 Battery

Note: Amazon links open in the new windows, feel free to check them for the most up-to-date offers and prices.