Mighty Max ML100-12 12V 100 Ah AGM Deep Cycle Battery

Mighty Max ML100-12 12V 100 Ah AGM is a BCI Group 27 battery, designed for deep cycle, off-the-grid applications.

Mighty Max ML100-12 is an affordable and reliable 100 Ah battery that is not well suited for starting/cranking applications, but it can be used as an excellent trolling motor battery, solar battery, standby battery, for electric vehicles, and carts, etc.

Published: September 4, 2019.

Mighty Max ML100-12 Features and Specifications

Mighty Max ML100-12 is a maintenance-free, spill-proof Absorbent Glass Mat (AGM) lead-acid battery, featuring a heavy-duty calcium-alloy grid for deep cycle operations.

Mighty Max ML100-12 is BCI group 27 battery, with dimensions (L x W x H) of 12.0 x 6.63 x 8.29 (8.48 with terminals) inches (305.5 x 168.5 x 210.5/215.5 mm).

Some sources claim that Mighty Max ML100-12 is a BCI group 30H (13.5 x 6.8125 x 9.25 inches) battery, but battery group 27 can fit the battery group 30H compartment easily.

Mighty Max ML100-12 is also one of the lightest AGM 100 Ah batteries - it weighs 63.9 lbs (~29 kg) and it features two handles for carrying it around.

Mighty Max ML100-12 features internal thread terminal posts, ensuring firm contact between the battery and the battery cables.

Mighty Max ML100-12 is designed for 10-year standby use and it comes with a 1-year warranty.

Operating temperatures are:

- storage: from -4°F to 140°F (-20°C to 60°C),

- charging: from 14°F to 140°F (-10°C to 60°C),

- discharging: from -4°F to 140°F (-20°C to 60°C).

Mighty Max ML100-12 may be used in standby and in deep cycling applications. When being used in standby applications, the maximum recommended charging voltage is 13.6 - 13.8 volts. When the battery is used in cycling applications, the maximum charging voltage should be 14.5 - 14.9 volts.

When the battery is being charged using constant voltage, the charging voltage should be in the 13.8 and 14.1 volts range.

In any case, the charging voltage should NOT be more than 15.0 volts and the charging current should NOT be larger than 27-30 Amps.

Mighty Max ML100-12 features a low self-discharge rate, which is ~3% per month at 68°F (20°C), allowing the battery to remain in the storage for up to 6 months at room temperature, without the charge dropping below 20% DoD (or 80% SoC).

The internal resistance of the fully charged Mighty Max ML100-12 battery at 77°F (25°C) is 5 mΩ. Short circuit current is ~1800 Amps and maximum 5s current is ~900 Amps - not the most impressive currents for 100 Ah 12V AGM battery, but again, this is NOT what is this battery designed for!

Mighty Max ML100-12 Discharging Features

Constant current discharge characteristics of the Mighty Max ML100-12 are given in the following chart (in Amps, at 77°F/25°C):

End Voltage Per Cell	Battery End Voltage	10 min	15 min	30 min	45 min	1 hour	3 hours	5 hours	10 hours
1.60 V	9.6 V	207	162	92.0	66.5	53.5	24.0	16.2	9.20
1.65 V	9.9 V	195	154	89.3	65.1	52.5	23.5	16.0	9.15
1.70 V	10.2 V	183	145	86.4	63.6	51.3	23.0	15.7	9.10
1.75 V	10.5 V	170	136	83.2	62.0	50.0	22.5	15.4	9.05
1.80 V	10.8 V	155	126	80.0	60.0	48.5	21.8	15.0	9.00

Constant power discharge characteristics of the Mighty Max ML100-12 battery are given in the following chart (in watts, at 77°F/25°C):

End Voltage Per Cell	Battery End Voltage	10 min	15 min	30 min	45 min	1 hour	2 hours	3 hours	5 hours
1.60 V	9.6 V	2250	1830	1032	750	618	372.0	280.8	189.0
1.65 V	9.9 V	2178	1734	1008	738	606	366.0	276.0	187.2
1.70 V	10.2 V	2100	1686	978	726	594	358.2	270.6	185.4
1.75 V	10.5 V	2010	1626	948	708	582	349.2	265.2	183.0
1.80 V	10.8 V	1890	1548	912	690	570	339.6	259.6	180.0

Note: these values are average values and they vary slightly from the battery to battery.

Mighty Max ML100-12 Cycle Service Life

The service life of deep cycle batteries is often measured in the number of cycles that the battery can withstand with a certain capacity loss.

The number of cycles also depend on the DoD% (Depth of Discharge percentage) and for Mighty Max ML100-12 cycle service life is:

- 100% DoD: ~185 cycles down to 80% capacity, ~250 cycles down to 60% capacity,

- 50% DoD: ~360 cycles down to 80% capacity, ~470 cycles down to 60% capacity.

- 30% DoD: ~940 cycles down to 80% capacity, ~1500 cycles down to 60% capacity.

For short, the operational life of the Mighty Max ML100-12 can be extended by avoiding discharging the battery below a certain level (10.5 volts for large loads/currents, 10.8 volts for small loads/currents).

Mighty Max ML100-12 as Trolling Motor Battery

With its 100 Ah capacity, Mighty Max ML100-12 can be used as a high-capacity trolling motor battery.

Small trolling motors requiring some 20 Amps (or larger trolling motor with decreased power) can be powered for at least 3 hours with some energy left.

Larger trolling motors requiring ~50 Amps can be powered for ~1 hour, but this time can be extended if the trolling motor is not pushed to its limit all the time.

Note: If your trolling motor is operating almost all the time at full throttle, your trolling motor is under-dimensioned. For safety reasons get a stronger one and consider a larger battery (or more batteries), again, for safety reasons.

Boats with single battery electric systems may use Mighty Max ML100-12 even for starting small internal combustion engines, as long as their cranking Amps are below 200 Amps.

Note: as the Mighty Max ML100-12 battery is being discharged during trolling (or any other application requiring the use of a single onboard Mighty Max ML100-12 battery), the battery's capability to provide large cranking currents is decreased. Worst case scenario - if Mighty Max ML100-12 is discharged below a certain level, You will have to manually start the engine or you can use some kind of battery jumper.

Boats with two batteries electrical system may use Mighty Max ML100-12 as deep cycle marine AGM battery not only for trolling but for all other purposes as well, like navigation lights, onboard electronics, fish finders, etc. And if/when the Mighty Max ML100-12 is fully discharged, a fully charged cranking battery is used for starting the boat's engine(s).

Mighty Max ML100-12 as Fishing Kayak Battery

Fishing kayaks, especially ocean-going fishing kayaks are more and more filled with electric and electronic equipment requiring a stable and reliable source of power.

Although Mighty Max ML100-12 is one of the lightest 100 Ah 12V AGM batteries, note that it is still rather heavy - it weighs 63.9 pounds (~29 kg) and its positioning on the kayak must be as low as possible, preferably below the waterline, in a watertight compartment.

If such battery is positioned above the waterline, the stability of the kayak is jeopardized - such kayak can easily tumble over, and that is not something nice, especially when big game fishing, with all the chum in the water :)

Typical electric equipment found on large(r) kayaks includes LED navigation lights (1 - 3 Amps), fish finder (0.2 - 3 Amps), trolling motor (10-25 Amps, rarely more), communication devices (marine radio, smartphones, etc.), etc.

Mighty May ML100-12 is well suited for such electric load, but its endurance (like endurance of all similar batteries) depends on the fishing habits of the user - if the largest load (kayak trolling motor) is used at full throttle, even 100 Ah battery will not last more than ~3h.

For short: if you need trolling motor for your fishing kayak and you plan on trolling all day long, consider either lithium trolling motor batteries or even a small gas outboard engine.

Mighty Max ML100-12 vs Other 100 Ah 12V AGM Batteries

The following chart lists the most popular ~100 Ah marine batteries and their features and specifications (alphabetic order):

Note: Amazon affiliate links in the chart open in the new windows, feel free to check them for more reviews and recommendations.

Also, there are many other marine, automotive, off-the-grid, solar, general-purpose, and similar batteries in the 100 Ah range, but these are most popular due to their combination of durability, performance, and price - hence, we consider them to be 'the best' 100 Ah 12V batteries.

Mighty Max ML100-12 is not designed for cranking applications, but it can start smaller gas and diesel engines (requiring max. 150-200 MCA), can be used as trolling motor battery, solar battery, RV battery, etc.

Also, it is one of the most cost-effective and affordable 100 Ah 12V AGM batteries on the market.

So, if you are looking for a deep cycle AGM battery and its features fit your needs, consider it as your new battery.

For more reviews and the most up-to-date prices and offers, check Mighty Max ML100-12 12V 100 Ah AGM Battery Amazon link (link opens in the new window).