ExpertPower EXP12180 12V 18 Ah AGM Battery

ExpertPower EXP12180 is very popular and well balanced AGM lead acid battery, featuring nominal voltage of 12 volts and nominal 20h capacity of 18 Ah. It is Sealed Lead Acid (SLA) Absorbent Glass Mat (AGM) battery with the battery case made of ABS plastic, very resistant to mechanical shocks and impacts, vibrations, chemicals and heat.

ExpertPower EXP12180 is designed to be used in cycling and floating applications, with float life span of 3 to 5 years. In cycling applications, it is commonly used in various toys, electric vehicles, as small solar and general off-the-grid battery and similar. And it comes at very acceptable price.

All these are reasons why ExpertPower EXP12180 is one of the most popular batteries in its class.

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ExpertPower EXP12180 AGM Battery - Features and Specifications

As an AGM battery, ExpertPower EXP12180 is practically maintenance free battery with very low self-discharge rate, especially at lower temperatures.

Physical dimensions of the battery are (L x W x H) 7.12 x 3.03 x 6.57 inches (~18.1 x 7.7 x 16.7 cm) and it weighs 11.68 pounds (~5.3 kg).

Fully charged ExpertPower EXP12180 battery features internal resistance of ~12 mΩ, measured at 77°F (25°C).

Maximum charging current is 5.4 Amps, enabling the user to charge the battery rather fast, although charging currents around 2 Amps are recommended for the 'bulk' charging phase.

Charging voltage at 77°F (25°C) for the cycling use is in the 14.4 - 15.0 volts range (-30mV/°C), and for the float use, charging voltage is in the 13.5 - 13.8 volts range (-20mV/°C).

Note: personally, I don't like the idea of charging AGM batteries above 14.8 volts (at 77°F/25°C).

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ExpertPower EXP12180 features M5 Bolt & Nut terminal posts - when the battery is charged and maintained with intelligent 2-3 Amps AGM battery charger, the only actual maintenance task is checking from time to time if there are corrosion on the terminals and connecting wires (rarely can happen, but check just in case ...).

Self-discharge rate is low and it depends on the storage temperature:

- 104°F (40°C): ~40 days down to 80% SoC, ~2 months down to 70% SoC, ~3 months down to 60% SoC,

- 86°F (30°C): ~50 days down to 80% SoC, ~100 days down to 70% SoC, ~6 months down to 60% SoC,

- 77°F (25°C): ~3 months down to 80% SoC, ~6.5 months down to 70% SoC, ~10 months down to 60% SoC,

- 41°F (5°C): ~2 months down to 90% SoC, ~10 months down to 80% SoC, ~20 months down to 70% SoC.

As one can see, as the storage temperature drops, self-discharge rate drops significantly. When storing AGM batteries, it is good practice not to let them discharge below 80% SoC (or 20% DoD).

ExperPower EXP12180 AGM Battery Discharge Characteristics

ExperPower EXP12180 AGM battery behaves similarly to all other AGM batteries - as the discharge current is increased, actual capacity drops:

- 20 hr capacity (0.90 Amps, down to 10.5 volts, at 77°F/25°C): 18 Ah,

- 10 hr capacity (1.73 Amps, down to 10.5 volts, at 77°F/25°C): 17.3 Ah,

- 5 hr capacity (3.24 Amps, down to 10.5 volts, at 77°F/25°C): 16.2 Ah,

- 1 hr capacity (10.85 Amps, down to 10.5 volts, at 77°F/25°C): 10.85 Ah.

Increasing the discharge current even more, leads to even more drop in actual capacity - again, this is feature of all lead acid batteries, not just ExperPower EXP12180 battery.

The following chart shows the constant current discharge characteristics of the ExpertPower EXP12180 battery.

Values are given in Amps, measured at 77°F (25°C):

V/Cell V/Battery 5 min 10 min 15 min 30 min 1 hr 2 hr 3 hr 4 hr 5 hr 6 hr 10 hr 20 hr
1.85 11.1 59.18 34.94 28.46 17.90 10.45 6.04 4.64 3.808 3.120 2.544 1.668 0.867
1.80 10.8  60.31  35.60  28.98  18.24  10.65  6.15  4.73  3.880  3.180  2.592  1.700 0.882
1.75 10.5  61.44  36.27  30.51  18.58  10.85  6.27  4.81  3.953  3.239  2.641  1.732  0.900
1.70 10.2  66.97  38.45  32.22  19.32  11.04  6.38  4.90  4.023  3.296  2.687  1.762  0.916
1.67 10.02  73.73  41.71  34.78  20.40  11.15  6.45  4.95  4.066  3.332  2.716  1.781  0.926
1.60 9.6  79.87  43.89  35.90  21.28  11.27  6.52  5.00  4.110  3.368  2.745  1.800  0.936

Similarly, the following chart shows the constant power discharge characteristics of the ExpertPower EXP12180 battery.

Values are given in watts, measured at 77°F (25°C):

V/Cell V/Battery 5 min 10 min 15 min 30 min 1 hr 2 hr 3 hr 4 hr 5 hr 6 hr 10 hr 20 hr
1.85 11.1 692.4 408.7 321.2 209.4 122.2 70.6 54.2 44.6 36.5 29.8 19.5 10.14
1.80 10.8  705.7 416.6  327.4  213.4  124.6  72.0  55.3 45.4  37.2 30.3 19.9  10.32
1.75 10.5  718.9  424.4  333.5  217.4  126.9  73.3  56.3 46.2  37.9  30.9  20.3  10.56
1.70 10.2  783.5  449.8  353.5  226.1  129.1  74.6  57.3  47.0  38.8  31.4  20.6  10.74
1.67 10.02  862.6  488.0  383.6  238.7 130.5  75.4 58.0  47.6  39.0  31.8  20.8  10.86
1.60 9.6  934.6  513.5  403.6  248.9  131.9  76.2  58.6  48.1 39.4  32.1  21.1  10.92

When the ExpertPower EXP12180 battery is being discharged for longer than ~40 minutes, gain in the delivered power by discharging the battery to the lower end voltage is not significant.

For example, when the battery is being discharged for 5 hours with the end voltage of 11.1 vs 9.6 volts, power difference is ~7.4%.

But, when the battery is being discharged for 30 minutes or less, battery power can be increased by ending the discharge process with lesser battery voltage.

For example, when the battery is being discharged for 5 minutes with the end voltage of 11.1 vs 9.6 volts, power difference is ~26%.

Reason why this can be done lies in the AGM chemistry - when the AGM battery is being drained quickly, it can be, more or less safely, discharged down to 9.6 volts instead of 10.5 volts.

10.5 volts value is generally accepted 'safe' voltage below which one should not drain the AGM batteries, but when AGM batteries are drained faster, EXP12180 battery included, it can be drained to lower voltages.

Note: whenever the lead acid battery is discharged down to 20% DoD (80% SoC) or less, charge it right away - such charging can prolong the operating life of AGM batteries significantly, especially when the batteries are charged with smart AGM battery chargers.

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ExpertPower EXP12180 Service Life

When the ExpertPower EXP12180 is used in float applications, its service life is 3-5 years, depending on the operating temperature.

When th ExpertPower EXP12180 battery is used in deep cycling applications, its operating life (number of cycles) depends mostly on the depth of discharge (DoD):

- 100% DoD: capacity drop down to 80% after ~180-205 cycles, capacity drop down to 60% after ~190-260 cycles,

- 50% DoD: capacity drop down to 80% after ~330-410 cycles, capacity drop down to 60% after ~405-510 cycles,

- 30% DoD: capacity drop down to 80% after ~800-920 cycles, capacity drop down to 60% after ~1060-1215 cycles.

In order to increase number of charging/discharging cycles, don't fully discharge the battery.

 ExpertPower EXP12180 AGM Battery as Fish Finder Battery

ExpertPower EXP12180 can be used as an excellent and cheap fish finder battery in small boats, kayaks and similar vessels that don't have their own electric system.

Most fish finders consume around or less than 1 Amp of current, when powered from 12V sources. Smaller, portable models draw even less than that, but larger ones, especially fish finder/GPS combos can draw more than that.

garmin striker mFor example, one of the most popular, compact and rather versatile fish finders Garmin Striker 4 GPS Fish Finder (Amazon link, opens in the new window), draws ~0.23 Amps, when being powered with 12V source.

When the ExpertPower EXP12180 is being used for powering such device, user can expect at least 78 hours (more than 3 days) of constant operation, which can be important on fishing trips away from suitable power sources that can be used to charge fish finder batteries.

When the EXP12180 is being used for larger fish finder/GPS combo devices that draw, for example, 3 Amps, one can expect that this battery can power such devices for at least 5 hours.

If you are looking for a good fish finder battery that can be used for other purposes as well, consider ExpertPower EXP12180 battery.

ExpertPower EXP12180 AGM Battery as Trolling Motor Battery

ExpertPower EXP12180 is not recommended trolling motor battery, except for the smallest kayak trolling motors.

minnkota endura c2 mFor example, Minn Kota Endura C2 Transom Mount Electric Trolling Motor features 30 pounds of thrust with the maximum current of 30 Amps.

ExpertPower EXP12180 is able to provide 30 Amps of power for ~15 minutes with the voltage not dropping below 10.5 volts.

However, trolling motors are rarely used at full throttle all the time and if the power/current is reduced down to, for example, 18-19 Amps, ExpertPower EXP12180 can provide such current for ~30 minutes, with the voltage not dropping below 10.5 volts.

Unless you have a really small electric trolling motor and you don't need long operating time, ExpertPower EXP12180 is not the best trolling motor battery for your needs.

ExpertPower EXP12180 AGM Battery for Off-the-Grid Applications

solar panel mWhen being used for off-the-grid applications, ExpertPower EXP12180 AGM battery can be easily charged with solar panels during the daylight.

During the period of 10h during the night, ExpertPower EXP12180 can provide ~20 W (~1.73 Amps) of power constantly, which can be enough to power for example, navigational LED lights, or marine radio, or some similar device.

If required, it can be also used for powering smaller flat screen TV, smaller refrigerator, to be used for charging the smart phones, tablets, laptops etc, just be sure to monitor the battery's parameters like volts and current since such devices can be rather power hungry and can quickly discharge the battery.

How to Charge ExpertPower EXP12180 AGM Battery

When the battery is used as standalone unit, the best option is to use smart, microprocessor controlled AGM battery charger that can sense the battery condition and adapt the charging process to the battery being charged.

Also, such chargers are commonly used as battery equalizers and maintainers.

vmaxtanks bc1204 tExpertPower EXP12180 should be charged with the maximum current of 5.4 Amps, preferably with 2 Amps during bulk charging phase. Smaller chargers (1 Amp chargers, for example) can be used as well, although such chargers have longer charging times.

For example, VmaxTanks BC1204 smart battery charger features 3.3 Amps bulk phase charging current and can charge EXP12180 battery in ~6 hours.


expertpower exp12180 mLong Story Short: ExpetPower EXP12180 is one of the best buy batteries and one of the most popular batteries in its class.

It is durable, it can power broad range of devices, it is rather affordable, tolerates deep discharges and is easily charged using rather cheap smart AGM battery chargers.

If you are looking for the general purpose 12V AGM battery in the 15-20 Ah range, consider this one.

For more reviews and recommendations, check ExpertPower EXP12180 AGM Battery Amazon link (link opens in the new window).