VMAXTANKS Batteries V30-800, V35-857, MR96, MR107, SLR125, MR127, MR137, SLR155 and MR197 Comparison

VMAXTANKS Batteries V30-800, V35-857, MR96, MR107, SLR125, MR137, SLR155, and MR197 are the most common VMAXTANKS batteries used in marine, automotive, light industrial, and similar applications.

Although they are defined as 'deep cycle' batteries, they can be used as starting batteries, too, just one must be aware of their limitations.

Updated: February 6, 2023.

Features and Specifications

Technical data of the VMAXTANKS AGM batteries V30-800, V35-857, MR96, MR107, SLR125, MR137, SLR155 and MR197 are given in the following comparison chart:

Note: Amazon affiliate links (Model column) open in the new window, feel free to check them for the most up-to-date offers and prices.

Of course, there are many more VMAXTANKS batteries on the market, just keep in mind that "SLRs" are "Solar Batteries," and "MRs" are "Marine Batteries."

VMAXTANKS SLR batteries are actually "solar batteries," and they don't have an MCA rating defined since they are designed for long discharge using relatively low currents.

VMAXTANKS SLR125 Battery vs. VMAXTANKS MR137-120 Battery

These batteries are generally very similar:

• they both belong to the 31-battery group,
• their dimensions are 12.9 x 6.8 x 8.5 inches,
• they weigh around 75 pounds.

However, there are several very important differences:

• MCA (Marine Cranking Amps - maximum current that a new, fully charged, 12V battery (at 32°F - 0°C) can deliver for 30 seconds, with the voltage NOT dropping below 7.2V) rating for MR137 battery is 900 Amps, while for SLR125 battery this value is not even defined - SLR125 is not intended for strong charging/discharging currents.
• RC (Reserve Capacity - number of minutes that a new, fully charged, 12V battery, at 80°F (~25°C) can deliver 25A current and maintain at least 10.5V of voltage) rating for MR137 battery is 230 minutes and for SLR125 battery is 260 minutes. This difference doesn't sound much, but keep in mind that these batteries are of the same size and weight!
• 20h capacity for the MR137 is 120 Ah, and 125 Ah for SLR125.

Obviously, if one needs a deep cycle battery for an electric trolling motor, battery to power boat lights, sonar, GPS, laptops, tablets, winches, and similar, the SLR125 battery is a better choice.

If one needs a deep cycle battery but also has an internal combustion engine(s) (requiring far less than 900 cranking Amps), MR137 is a better choice.

Note that 900 Amps is the limit for a new, fully charged battery. Unfortunately, we were unable to find the MR137 manual (or any other VMAXTANKS battery manual) with a defined maximum allowed cranking current depending on the battery discharge state). If/When we find them, we will update this article with actual data from the manufacturer.

Electric Trolling Motor Operating Time

Most electric trolling motors have a maximum current of around 50-55 Amps. Only smaller electric trolling motors (15-40 lbs thrust range) have lower maximum currents, for example, Newport Vessels NV-Series 36 lb. Electric Trolling Motor at maximum speed draws around 29-30 Amps.

Much stronger electric trolling motors use 24 or 36V batteries but keep currents below 60 Amps - more Amps would require much thicker cables to reduce power dissipation and power loss.

Don't forget that all these batteries can be connected to a smart battery marine charger/controller and charged using solar panels and wind turbines without turning the main gas or diesel engine(s) on.

In most situations during fishing/trolling, a boat is not going at maximum speed, and running an electric motor on slightly lower power settings can prolong the battery operating time on a single charge significantly.

If we assume a hypothetical situation (based on real life!) where our electric trolling motor draws 25 Amps, the operating time is equal to the RC value of the fully charged, new battery.

In our case, that is:

• VMAXTANKS V30-800 battery, 55 minutes, less than one hour. If the motor is pushed harder for just a short period of time, the battery will soon be dead! Running a 50-60 Amp motor at full power will discharge this battery very quickly.
• VMAXTANKS V35-857 battery, 75 minutes - 1h 15 minutes. Better than V30-800, but still, if we push the motor slightly, this time will shorten significantly. Running a 50-60 Amp motor at full power will discharge this battery very quickly, too. VMAXTANKS V30-800 and especially V35-857 batteries are an excellent choice for slow discharge applications where lightweight batteries are required, for example, as a small boat or even kayak fish finder batteries or similar. If you need higher capacity with lower weight, use NiMH or Lithium batteries.
• VMAXTANKS MR96-60 battery, 120 minutes - 2h. Now, we are getting some decent operating time on a single charge. However, just to be sure that you can go back to the port without paddling, don't push the motor too much, or the battery will be discharged quickly. Running a 50-60 Amp motor on full power will discharge this battery in 35-50 minutes, depending on the state of the battery.
• VMAXTANKS MR107-85 battery, 160 minutes, 2h 40 minutes. This battery can easily tolerate occasional full throttle (50-60 Amps, instead of 25 Amps) and still return a fisherman safely to the port or start a smaller gas or diesel engine. Very nice battery :)
• VMAXTANKS SLR125 battery, 260 minutes, 4h 20 minutes. This is an excellent trolling motor battery, especially when used occasionally during the day, connected to the smart battery charger/controller with solar panels and wind turbines as an auxiliary electric power source. In such configuration, during summer or during windy conditions, it can last for weeks/months, depending on the daily use. However, even when charged, it can be used as starting battery only for the smallest gas or diesel engines, having really low starting currents.

• VMAXTANKS MR137 battery, 230 minutes, 3h, and 50 minutes. MR137 doesn't have the low current capacity of the SLR125 battery, but it is a sturdier battery that can tolerate large currents better. Personally, in most situations, I would choose MR137 over the SLR125 battery, but that is my opinion. One of the reasons is that MR137 can be used as starting battery, providing 900 Amps (again, new, fully charged) - it is more like a dual-purpose battery, not a deep cycle battery, but more on that later.
• VMAXTANKS SLR155 battery, 350 minutes, 5h 50 minutes when drained at 25 Amps. It is an excellent battery for low-current applications, including electric trolling motors. Just like SLR125, it can be connected to a smart battery marine charger/controller and charged using solar panels and wind turbines, and be operated for weeks/months without turning your gas or diesel engine on!
• VMAXTANKS MR197 battery, 450 minutes, 7h 30 minutes at 25 Amps. It is an excellent, heavy, sturdy battery, which can be used as a deep cycle marine battery, but also as starting battery. It is quite heavy - 112 lbs, ~51 kg - and it should be placed on a permanent, as low as possible position on the boat. With 1400 Amps MCA rating, large electric trolling motor currents (50-60 Amps) are not a problem for this battery, even for hours. It is also the most expensive VMAXTANKS battery in the review, but what you pay is what you get.

Reserve Capacity (RC) Comparison

Since I like to complicate things, in order to demonstrate the importance of the lead acid battery capacity and especially capacity loss when discharged at large currents, here is the comparison of these VMAXTANKS batteries according to the RC (in minutes) and weight ratio:

• V30-800, 55 min, 22 lbs -> 2.5 min/lbs,
• V35-857, 75 min, 25 lbs -> 3 min/lbs,
• MR96-60, 120 min, 43 lbs -> 2.8 min/lbs,
• MR107-85, 160 min, 55 lbs -> 2.9 min/lbs,
• SLR125, 260 min, 75 lbs -> 3.46 min/lbs,
• MR137, 230 min, 75 lbs -> 3.06 min/lbs,
• SLR155, 350 min, 90 lbs -> 3.88 min/lbs,
• MR197, 450 min, 112 lbs -> 4 min/lbs.

This comparison explains why V35-857 is a very popular small electric trolling motor battery, why MR137 is the preferred choice for medium electric trolling motors, and why MR197 is used for really heavy-duty applications or applications where longer operation time on a single charge is required.

VMAXTANKS MR137 Battery vs. Optima D31M battery

This comparison explains the differences between MR137 deep cycle marine battery and D31M "true dual purpose" marine battery.

Or, for short - "you win some, you lose some."

Technical data of these AGM batteries is given in the following table:

Note: Battery links in the table are Amazon affiliate links. Feel free to check them for more battery reviews and recommendations.

It is obvious that Optima D31M is much better suited for dual-purpose applications - although it is 14 pounds lighter (61 lbs vs. 75 lbs), the new, fully charged Optima D31M battery can provide 1125 cranking Amps compared with 900 Amps of MR137.

However, when drained at low currents, things change in favor of the MR137 battery, which has a much better RC rating (230 minutes vs. 155 minutes and 3.06 min/lbs vs. 2.54 min/lbs) and especially 20h capacity - 120 Ah vs. 75 Ah.

Perhaps it is not even fair to compare these batteries, but I hope that this article gave You insight into the most popular VMAXTANKS AGM deep cycle marine batteries and that you will eventually choose the 'perfect' battery or batteries for your needs.

How To Charge VMAXTANKS AGM Deep Cycle Batteries

To charge VMAXTANKS AGM lead acid batteries, advanced AGM battery chargers are highly recommended.

Such battery chargers analyze the battery first and only then charge it according to the battery condition - if required, the battery charger initiates desulfation, and after fully charging the battery, it may enter the cell equalization mode and maintenance mode.

When dimensioning the battery charger, it is recommended to charge the battery with, on average, 0.1 to 0.25C charging current.

Personally, one should aim for ~0.15C charging current when charging VMAXTANKS deep cycle AGM batteries.