Mighty Max ML35-12 AGM SLA Battery

Mighty Max ML35-12 is Absorbent Glass Mat (AGM) Sealed Lead Acid (SLA) battery with nominal voltage of 12 volts and nominal capacity of 35 Ah.

It is general purpose, deep cycling AGM battery, suitable for broad range of applications including trolling motor battery, fish finder battery, solar battery, for ATVs and other electric vehicles, security systems, and other off-the-grid applications.

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Mighty Max ML35-12 Features and Specifications

Mighty Max ML35-12 is AGM SLA battery - it means that it is spill proof and maintenance (almost) free battery. Also, since it is sealed battery, it is spill proof and can operate practically in any position.

Mighty Max ML35-12 physical dimensions are (L x W x H) 7.68 x 5.12 x 6.10 (7.09) inches (195 x 130 x 155/180 mm) and is rather compact.

Since it is lead acid battery, even such compact battery weighs 23.1 pounds (~10.5 kg).

Mighty Max ML35-12 is intended as deep cycle battery and its cranking/starting characteristics are rather limited - the battery is able to provide 330 Amps for 5 seconds. Also, it features internal resistance of ~10mΩ (fully charged, 77°F, 25°C), which is typical for deep cycle batteries of this size and capacity.

If you need lightweight dual purpose SLA AGM battery and you don't mind paying little bit extra, consider Odyssey PC925 AGM Battery.

Mighty Max ML35-12 AGM Battery features calcium-lead alloy thick plates, designed for deep discharge applications and low self-discharge rate.

Nominal voltage of Mighty Max ML35-12 AGM Battery is 12 volts, and nominal, declared 20h/10.5V capacity is 35 Ah. However, actual 20h capacity is somewhat different.

Note: nominal capacity of the lead-acid battery is capacity measured when the battery is being discharged for 20h, down to 10.5 volts at 77°F (25°C).

Actual capacity of the Mighty Max ML35-12 AGM Battery is given in the following list:

- 20h rate (1.75 Amps, down to 10.8V): 35 Ah

- 10h rate (3.3 Amps, down to 10.8V): 33 Ah,

- 5h rate (5.7 Amps, down to 10.5V): 28.5 Ah,

- 1h rate (20A, down to 9.6V): 20 Ah.

Mighty Max ML35-12 is designed for deep cycle applications, and while some manufacturers test 'nominal' voltage by discharging their batteries not only down to 10.5V, but to 10.05V for 20h, Mighty Max ML35-12 should not be discharged under 10.8 volts when being discharged more that 10h.

This doesn't mean that Mighty Max ML35-12 poorly recovers from deep discharges, it means that it can keep high voltage for longer period of time and deliver more energy, and not just current!

Mighty Max ML35-12 features 'nuts and bolts' terminals, and the only actual maintenance is avoiding corrosion on the terminal posts.

terminal

Mighty Max ML35-12 battery features low-self discharge rate. When the battery is stored at 68°F (20°C), it discharges at ~3% per month rate:

- Remaining capacity after 3 months: 90%

- Remaining capacity after 6 months: 80%

- Remaining capacity after 12 months: 60%

When the battery capacity drops below 80%, or after 6 months of storage, recharge the battery using smart AGM battery charger.

Maximum charging current is 10.5 Amps, with charging voltage for float applications in the 13.6 - 13.8 range and for cycle applications in the 14.4 - 14.7 volts (at 77°F, 25°C).

Mighty Max ML35-12 Constant Current and Power Discharge Charts

The following chart shows the constant current discharge characteristics of the Mighty Max ML35-12 battery (Amps at 77°F, 25°C):

End Voltage (V/Cell) End Voltage (V) 5 min 10 min 15 min 30 min 1h 3h 5h 10h 20h
1.60V 9.6V 114 79.2  61.5  36.3 20.0 8.61 6.01 3.43 1.83
 1.65V 9.9V 108 75.2  58.4  34.5 19.0  8.45  5.90  3.41  1.82
 1.70V  10.2V 101 70.7  54.9  32.4 18.1  8.30  5.81  3.38  1.80
 1.75V  10.5V  94.0 65.8  51.1  30.8 17.2  8.15  5.70  3.35  1.78
 1.80V  10.8V  86.5 60.5  47.0  28.3 16.3  8.01  5.60  3.30  1.75

Similarly, the following chart shows the constant power discharge characteristics of the Mighty Max ML35-12 battery (watts at 77°F, 25°C):

End Voltage (V/Cell) End Voltage (V) 5 min 10 min 15 min 30 min 45 min 1h 2h 3h 5h
1.60V 9.6V 1290 900 672 430.8 321.6 262.2 145.2 106.2 70.2
 1.65V  9.9V  1200  852  648  417.6  315  258  142.8  105  69.6
 1.70V  10.2V  1110  798  618  405  308.4  253.8  139.8  103.8  69
 1.75V  10.5V  1020  750  595.2  391.8  302.4  249  137.4  102  68.4
 1.80V  10.8V  960  696  570  378  295.8  244.8  134.4  100.8  67.8

Although Mighty Max ML35-12 battery is intended for deep cycle operations, it is also able to provide plenty of power when being discharged with strong currents.

Manufacturer doesn't state actual Reserve Capacity (value in minutes that is a new, fully charged battery able to provide 25 Amps at 77°F/25°C without the voltage dropping below 10.5 volts) of the Mighty Max ML35-12 battery, but extrapolating from these charts, Reserve Capacity of the Mighty Max ML35-12 battery is approximately 40-45 minutes (at least!).

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Mighty Max ML35-12 Cycle Service Life

When used for cycling operation, service life (number of charging/discharging cycles) of the Mighty Max ML35-12 battery depends on the Depth of Discharge and is given in the following list:

- 100% DoD: ~190 cycles with 80% capacity remaining, ~220 cycles with 60% capacity remaining,

- 50% DoD: ~370 cycles with 80% capacity remaining, ~460 cycles with 60% capacity remaining,

- 30% DoD: ~860 cycles with 80% capacity remaining, ~1170 cycles with 60% capacity remaining.

So, in order to prolong the Mighty Max ML35-12 service life, if possible, don't discharge your too much.

Mighty Max ML35-12 battery comes with 1-year warranty.


Long Story Short: Mighty Max ML35-12 is well balanced, reliable and versatile AGM SLA deep cycle battery. It is suitable for various application on boats like:

mighty max ml35 12 agm m- lightweight trolling motor battery (for motors up to 20-25 Amps, preferably less),

- large capacity fish finder battery,

- LED lights battery,

- for powering various onboard electronics,

- for staring small gas boat engines, etc.

Also, Mighty Max ML35-12 is suitable for many off-the-grid applications including solar/wind turbine battery, security systems, medical, standby etc.

For these and other reasons, Mighty Max ML35-12 is one of the most popular batteries in this class.

For more reviews and recommendations, and most up-to-date offers and prices, check Mighty Max ML35-12 Battery Amazon link (link opens in the new window).