WindyNation BAT-NSAP12-100 Group 31 AGM Deep Cycle Battery

WindyNation BAT-NSAP12-100 is 12V 100Ah Sealed Lead-Acid (SLA) Absorbent Glass Mat (AGM) BCI Group 31 battery, designed for various off-the-grid, float and deep-cycle applications like solar/wind battery, UPS backup battery, security/medical battery, RV house battery, electric trolling motor battery, etc.

Due to its balanced design and features, WindyNation BAT-NSAP12-100 is one of the most popular deep-cycle AGM batteries in its class, offering the users very good performances and affordable price.

Published: May 11, 2020.

WindyNation BAT-NSAP12-100 Features and Specifications

WindyNation BAT-NSAP12-100 features nominal voltage of 12 volts, nominal (20h) capacity of 106 Ah and 10h capacity of 100 Ah - since it is intended for solar/wind applications and it is expected to provide power during the night for '10 hours', WindyNation BAT-NSAP12-100 is labeled with its actual '10 hours' capacity.

Since the WindyNation BAT-NSAP12-100 is sealed AGM battery, it may be operated in any position except upside down.

Physical dimensions of the WindyNation BAT-NSAP12-100 are (L x W x H) 13.0 x 6.8 x 8.7 inches (33 x 17.3 x 22 cm) and as such, it belongs to the BCI 31 battery group with a maximum allowed battery size of ~13 x 6.8 x 9.44 inches.

WindyNation BAT-NSAP12-100 battery weighs around 67 pounds (~30.4 kg), which is in range with other similar group 31 batteries.

WindyNation BAT-NSAP12-100 internal resistance is ~4.9 mΩ, and although it is not designed as a starting/cranking battery, it is nonetheless able to provide 1200 Amps for 5 seconds.

The manufacturer doesn't state actual Reserve Capacity value, but according to the battery's discharge tables, Reserve Capacity is slightly over 180 minutes (3+ hours). Cold Cranking Amps (CCA) and Marine Cranking Amps (MCA/CA) values are not given - after all, this is NOT starting/cranking battery.

WindyNation BAT-NSAP12-100 features T11 terminal posts (positive to the left side of the battery).

When the WindyNation BAT-NSAP12-100 battery is being used in standby/float applications (UPS battery, security systems, etc.), its charging voltage should be in the 13.5 - 13.8 volts range, with a temperature coefficient of -20mV/°C.

When the WindyNation BAT-NSAP12-100 battery is used in deep cycle applications (solar/wind off-the-grid applications, electric vehicles, etc.), charging voltage should be in the 14.4 - 15.0 volts range, with a temperature coefficient of -30mV/°C.

Note: Regardless of the actual use, the maximum charging current should be kept below 30 Amps, in order to prolong the battery operating life, avoid overheating, and even gassing. That means that if the battery was discharged below 50% DoD (~53 Ah), it will take at least 2 hours to recharge the battery using 30 Amps charging current.

Personally, don't charge it with 25+ Amps currents - preferably, keep the charging currents below 20 Amps and the battery will last for a long time. Battery features pure lead plates and extra-long float life (10-12 years), so keeping the charging currents in check can achieve really extra long operating life.

WindyNation BAT-NSAP12-100 Discharging Charts

Constant current discharge features of the WindyNation BAT-NSAP12-100 are given in the following chart - values are given in Amps, at 77°F/25°C:

End Battery Voltage	End Cell Voltage	10 min	15 min	20 min	30 min	45 min	1 hour	2 hours	3 hours	5 hours	10 hours	20 hours
10.8	1.80	167.6	143.7	123.5	92.1	68.7	55.1	33.1	24.6	17.2	10.0	5.2
10.5	1.75	186.3	154.0	130.8	96.5	71.3	57.1	34.4	25.4	17.6	10.1	5.3
10.2	1.70	199.5	165.1	138.9	101.8	74.6	59.5	35.3	26.0	17.9	10.2	5.3
9.9	1.65	215.1	178.5	146.6	106.7	77.4	61.9	36.3	26.7	18.3	10.3	5.4
9.6	1.60	232.5	188.5	154.3	112.3	80.5	63.8	37.5	27.6	18.6	10.5	5.5

As one can see, WindyNation BAT-NSAP12-100 is able to provide large currents for short periods of time, making it useful even as starting battery for small internal combustion gas engines, commonly found at smaller boats, power generators and similar AND be used as deep cycle battery when the main engine is turned off (as trolling motor battery, as power inverter battery and similar).

But, if possible, use it in two battery electrical systems - crank the engine with smaller cranking/starting battery and use WindyNation BAT-NSAP12-100 as a deep cycle battery.

Constant power discharge features of the WindyNation BAT-NSAP12-100 are given in the following chart - values are given in watts, at 77°F/25°C:

End Battery Voltage	End Cell Voltage	10 min	15 min	20 min	30 min	45 min	1 hour	2 hours	3 hours	5 hours	10 hours	20 hours
10.8	1.80	1872.0	1626.0	1410.6	1060.8	796.2	643.2	382.8	286.2	201.6	118.8	61.8
10.5	1.75	2069.4	1732.2	1486.8	1105.8	823.8	664.8	396.0	294.6	205.8	119.4	62.4
10.2	1.70	2199.0	1846.2	1570.8	1161.6	858.0	690.0	405.6	300.6	208.8	120.6	63.0
9.9	1.65	2348.4	1981.2	1647.0	1211.4	886.2	714.6	415.2	307.8	211.8	121.8	63.6
9.6	1.60	2509.2	2070.6	1719.6	1266.6	917.4	734.4	426.6	316.2	215.4	123.0	64.2

As one can see, WindyNation BAT-NSAP12-100 can provide plenty of power for short periods of time, but the best results are achieved when the battery is drained for 2 or more hours - when being discharged for 2 hours down to 10.5 volts, it can provide 396 watts, and when combined with high-efficiency 500W pure sine inverter, it can be used to power a broad range of loads during these 2 hours.

Of course, this is just an example - WindyNation BAT-NSAP12-100 can be connected in series and parallel to increase capacity/voltage of the battery pack and combined with various solar/wind/generator charge controllers and power inverters, and provide power levels as required.

When the WindyNation BAT-NSAP12-100 battery is being used as a deep cycle battery, the number of charging/discharging cycles depends on the Depth of Discharge (DoD) of each cycle.

On average, WindyNation BAT-NSAP12-100 battery can withstand:

- 30% DoD: ~850 cycles with the capacity loss down to 80% capacity, ~1120 cycles with the capacity loss down to 60% capacity,

- 50% DoD: ~380 cycles with the capacity loss down to 80% capacity, ~460 cycles with the capacity loss down to 60% capacity,

- 100% DoD: ~190 cycles with the capacity loss down to 80% capacity, ~280 cycles with the capacity loss down to 60% capacity.

Obviously, avoiding too many too low DoD discharges can significantly increase the number of charging/discharging cycles.

In order to avoid too deep discharges, it is good to know the actual battery State of Charge (SoC) or Depth of Discharge (DoD) voltage at 77°F/25°C:

State of Charge (SoC %)	Depth of Discharge (DoD %)	Open Circuit Cell Voltage	Open Circuit Battery Voltage
100	0	2.14	12.84
75	25	2.09	12.54
50	50	2.04	12.24
25	75	1.99	11.94
0	100	1.94	11.64

For example, if the battery is kept at room temperature (77°F, 25°C) and it is NOT discharged below 50% DoD (keeping the battery open-circuit voltage at least 12.24 volts), the battery should withstand ~380 charging/discharging cycles with the capacity loss down to 80% of nominal capacity and ~460 charging/discharging cycles with the capacity loss down to 60% of nominal capacity.

WindyNation BAT-NSAP12-100 vs. Other BCI Group 31 Batteries

The following cross reference chart lists some of the most popular BCI Group 31 Batteries with their most important features and specifications:

WindyNation BAT-NSAP12-100 is a performance-wise mid-range group 31 battery. But, it is a reliable battery, tested in various real-life situations by many users.

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Long Story Short: If you are looking for well balanced deep cycle BCI Group 31 battery, consider WindyNation BAT-NSAP12-100 battery.

Although it features very low internal resistance and is able to provide 1200 Amps for 5 seconds, it is a true deep-cycle battery used for various cyclic and float applications.

As such, it is one of the most popular Group 31 deep cycle batteries.

For more reviews and recommendations, feel free to check WindyNation BAT-NSAP12-100 Deep Cycle AGM Battery Amazon link (link opens in the new window).