Deep Cycle Marine Battery

Renogy 12V 100Ah AGM RNG-BATT-AGM12-100 Deep Cycle Battery

Renogy RNG-BATT-AGM12-100 is a general-purpose Sealed Lead Acid (SLA) Absorbent Glass Mat (AGM) battery, designed for deep discharge cycle and standby applications. Although it is not intended for craning applications, the Renogy 12V 100Ah AGM battery is nonetheless able to provide relatively strong currents for short periods of time.

As such, Renogy RNG-BATT-AGM12-100 is often used as a trolling motor battery, as a backup sump pump battery, as an emergency battery security, medical and similar systems, as off-the-grid battery, etc.

Published: February 3, 2021.

renogy 12v 100ah agm w400px

Renogy RNG-BATT-AGM12-100 Battery Features and Specifications

Renogy RNG-BATT-AGM12-100 features physical dimensions of (L x W x H) 13.1 x 6.9 x 8.6 inches (~332 x 175 x 219 mm) and it is classified as a BCI Group 31 battery, although it is 0.1 inch longer - this 0.1 inch is not that important, but it should be noted.

According to the manufacturer, Renogy RNG-BATT-AGM12-100 features a 10h capacity of 100Ah (down to 10.5V, @77°F/25°C). However, according to the constant current discharge table, Renogy RNG-BATT-AGM12-100 features a 20h capacity of 100Ah and 10h capacity of 95.2 Ah.

Note: 'older' specification sheet of the Renogy RNG-BATT-AGM12-100 was more accurate regarding discharge currents and capacity and according to them, 10h capacity was 100Ah and 20h capacity was 104Ah. However, each battery in real-life features somewhat different specifications than the officially labeled (average) values.

Renogy RNG-BATT-AGM12-100 battery is a sealed, Valve Regulated Lead-Acid (VRLA) battery, based on the Absorbent Glass Mat (AGM) technology - it is a spill-proof, maintenance-free battery that is very resistant to vibrations and mechanical impacts.

Although the battery can operate even when on its sides, it is recommended to install the battery in the upright position. Do NOT install it upside-down!


The battery weighs 63.9 pounds (~29 kg) and it can be carried to shorter distances by two adults.

Battery terminals are M8 (bolts and washers included), ensuring a firm connection between the battery terminals and cables.

The internal resistance of the battery is ~5 mΩ - Renogy RNG-BATT-AGM12-100 AGM battery features a maximum discharge current of 1100 Amps for 5 seconds.

The maximum charge current is 30 Amps while charging voltage depends on the battery use (@77°F/25°C):

- Float Charge Voltage: 13.5 - 13.8V, with temperature compensation of -18mV/°C,

- Cycle Use Voltage: 14.4 - 14.8V, with temperature compensation of -24mV/°C.

When the battery is stored @77°F/25°C, its self-discharge rate is <3% per month - fully charged Renogy RNG-BATT-AGM12-100 can be stored at room temperature up to 6 months easily without the remaining charge dropping below 80% SoC.

Since the self-discharge rate depends on the temperature, Renogy RNG-BATT-AGM12-100 and other lead-acid batteries should be stored in dry and cool area.

renogy 12v 100ah agm 2

Cycle service life is usually defined as the number of charging/discharging cycles that the battery may withstand with the actual capacity not dropping below a certain threshold, usually 80% or 60% of the nominal capacity.

When used at 77°F/25°C, Renogy RNG-BATT-AGM12-100 is able to withstand:

- 100% DoD: ~200 cycles down to 80% capacity, ~250 cycles down to 60% capacity,

- 50% DoD: ~370 cycles down to 80% capacity, ~460 cycles down to 60% capacity,

- 30% DoD: ~870 cycles down to 80% capacity, ~1150 cycles down to 60% capacity.

For example, if the Renogy RNG-BATT-AGM12-100 is being discharged down to 50% DoD (Depth of Discharge), it can withstand ~370 cycles with the capacity loss down to 80% of nominal capacity - that is more than a year of daily use of this battery (down to 50% DoD).

Renogy RNG-BATT-AGM12-100 Constant Current and Constant Power Discharge Charts

It is a general rule of thumb that the lead-acid batteries should not be discharged below 10.5 volts in order to prevent any damage due to the over-discharge condition.

However, when lead-acid batteries, especially AGM batteries are discharged with stronger currents, their end voltages actually depend on the discharge current:

- discharge current I<0.2C (20 Amps): end voltage not less than 1.75V per cell (10.5V the for battery),

- discharge current 0.2C<I<0.5C (20-50 Amps): end voltage not less than 1.70V per cell (10.2V the for battery),

- discharge current 0.5C<I<1C (50-100 Amps): end voltage not less than 1.65V per cell (9.9V the for battery),

- discharge current I>1C (>100 Amps): end voltage not less than 1.60V per cell (9.6V the for battery).

But, when discharging the battery, regardless of the end-voltage, be sure to charge it right away, or at least as soon as possible.

Following charts list discharge values of constant current and constant power for Renogy RNG-BATT-AGM12-100 when being discharged at 77°F/25°C.

Note: values are given for a new, fully charged Renogy RNG-BATT-AGM12-100 battery.

Renogy RNG-BATT-AGM12-100 Constant Current (A) Discharge Chart

Battery Cell
End Voltage
End Voltage
15 min 30 min 1 hour 3 hours 5 hours 8 hours 10 hours 20 hours
1.60V 9.6V 165.5 100.00 58.70 26.76 17.90 11.78 9.81 5.15
1.67V  10.02V  158.7  96.51  57.00  26.20  17.50  11.68  9.71  5.10
1.70V  10.2V  155.9  91.23  55.10  25.83  17.33  11.59  9.62  5.05
1.75V  10.5V  149.1  86.32  54.00  25.56  17.24  11.40  9.52  5.00
1.80V  10.8V  142.4  79.62  50.20  25.09  17.05  10.93  9.33  4.90
1.85V  11.1V  130.8  70.19  47.40  24.26  16.76  10.75  9.14  4.80

As one can see from the discharge chart, the 20h capacity of the Renogy RNG-BATT-AGM12-100 is 100Ah and 10h capacity is 95.2 Ah when the battery is being discharged down to 10.5 volts @77°F/25°C.

Renogy RNG-BATT-AGM12-100 Constant Power (W) Discharge Chart

Battery Cell
End Voltage
End Voltage
15 min 30 min 1 hour 3 hours 5 hours 8 hours 10 hours 20 hours
1.60V 9.6V 1824 1074 646.2 311.6 213.1 141.3 117.7 61.80
1.67V  10.02V  1766  1050  634.8 306.7  209.1  140.1  116.6  61.20
1.70V  10.2V  1743  1005  624.0 303.3  207.4  139.1  115.4  60.60
1.75V  10.5V  1674  962.3  616.8  301.6  137.5  136.8  114.8  60.30
1.80V  10.8V  1599  910.2  582.0  298.8  205.1 132.3  113.1  59.40
1.85V  11.1V  1483  814.5  559.2  292.8 204.0  130.7  111.4  58.50

Note: this chart lists values for the Renogy RNG-BATT-AGM12-100 battery, not the 'Watts per Cell' (WPC).

How to Charge Renogy RNG-BATT-AGM12-100 Battery

 The charging method of the Renogy RNG-BATT-AGM12-100 battery depends on its use - if it is part of some larger system that features a suitable built-in battery charger, let that battery charger take care of the battery. Just be sure that the maximum charging current is kept below 30A and that the charging voltages are not above the recommended ones.

On the other hand, if the battery is being charged using a dedicated battery charger, an intelligent AGM battery charger with a maximum charging current of 30 Amps is recommended.

For example, if the battery is being discharged down to 50% DoD, then 20 Amps AGM battery charger may recharge the battery in less than 3 hours. Also, such battery chargers often feature temperature probe for sensing the ambient temperature (combined with automatic charging voltage adjustment), battery analysis mode, automatic adjustment of the battery process according to the battery condition, they feature battery maintenance mode, cells' equalization mode, etc.

If the battery is being used for powering smaller electric trolling motors (20-25 Amps max) or larger electric trolling motors at half the throttle (again, 25 Amps max), Renogy RNG-BATT-AGM12-100 is able to provide 25 Amps for three hours down to 10.8 volts, constantly.

Renogy RNG-BATT-AGM12-100 Battery as Trolling Motor Battery

Renogy RNG-BATT-AGM12-100 battery can be used as an excellent, general-purpose electric trolling motor battery.

When the battery is used for powering larger trolling motors (50-60 lbs of thrust @12V) that require up to 50 Amps of power, Renogy RNG-BATT-AGM12-100 battery is able to power such motor for one hour - a new, fully charged battery, @77°F/25°C is able to provide 50.20 Amps for one hour, down to 10.8 volts.

That means that after one hour of providing 50 Amp, the Renogy RNG-BATT-AGM12-100 battery is still not discharged fully. In order to prolong the battery's operating life, don't discharge the battery below 10.5 volts, preferably not below 10.8 volts.

Renogy RNG-BATT-AGM12-100 Battery as a Backup Sump Pump Battery

Renogy RNG-BATT-AGM12-100 battery can be used as an excellent backup sump pump battery.

When the battery is charged to 13.5 volts (2.25 volts per cell) its float life expectancy depends on the storage temperature:

- @20°C: ~9 years,

- @25°C: ~8.5 years,

- @30°C: ~6 years,

- @40°C: ~30 months,

- @50°C: ~15 months.

Of course, actual float life also depends on battery charger/maintainer quality, how many times the battery was discharged and how deep and similar.

But, in order to prolong its operating life, keep your lead-acid batteries in a cool area!

 On average, sump pump battery requirements depend on the sump pump power, for example:

- 1/2 HP: ~35 Amps@12 volts,

- 3/4 HP: ~50 Amps@12 volts,

- 1 HP: ~70 Amps@12 volts, ~35 Amps@24 volts,

- 1.5 HP: ~50 Amps@24 volts, ~35 Amps@36 volts.

Renogy RNG-BATT-AGM12-100 battery is able to provide 35 Amps for almost 5 hours and 50 Amps for 3 hours constantly.

Since sump pumps operate using the On/Off principle, the actual runtime of the sump pumps being powered by Renogy RNG-BATT-AGM12-100 battery may be much longer and depends on the actual sump pump power, the efficiency of the built-in power inverter, and similar.

renogy 12v 100ah agm w150pxLong Story Short: Renogy RNG-BATT-AGM12-100 battery is well balanced, general-purpose, deep-cycle AGM battery. Thanks to its performance and affordable price, it is one of the most popular batteries in its class.

Renogy RNG-BATT-AGM12-100 battery may be used in many applications that require a strong and reliable source of power, despite its weight - lithium batteries are commonly 2-3 lighter than lead-acid batteries, but they cost many times more ...

If You are looking for a 12V 100Ah spill-proof, maintenance-free AGM group 31 battery, consider this model.

For more reviews and recommendations, feel free to check the Renogy 12V 100Ah Deep Cycle AGM Battery Amazon link (link opens in the new window).

Recommend This Page

Search Deep Cycle Marine Battery

Go to Top