Universal Power Group UB12750 12V 75Ah Sealed Lead Acid Battery

Universal Power Group UB12750 is 12V 75Ah Sealed Lead Acid (SLA) Absorbent Glass Mat (AGM) general-purpose, deep cycle battery.

UPG UB12750 belongs to very popular BCI Group 24 batteries and is one of the most popular batteries in its class, commonly used in off-the-grid applications, as a small trolling motor battery, as a UPS battery, in security and medical applications, etc.

Published: February 24, 2021.

Universal Power Group UB12750 Features and Specifications

UPG UB12750 is a spill-proof, maintenance-free battery, with increased resistance to mechanical impacts and vibrations. Also, if features a low self-discharge rate, affordable price, and good charging and discharging characteristics.

Note: Universal Power Group UB12750 is designed as a deep cycle, general-purpose battery and although it can provide rather strong currents, it should not be used as starting/cranking battery, except for smaller internal combustion engines requiring 200-300 Amps max. starting currents - UPG UB12750 battery features internal resistance of 8mΩ.

UPG UB12750 battery comes in two versions: UPG UB12750-45821 (also sometimes labeled as UPG UB12750-46082) with Z1 terminals and UPG UB12750-45822 (also sometimes labeled as UPG UB12750-46009) with I4 terminals.

All other features of these two batteries are practically the same. Nonetheless, all further data in this article are given for the UPG UB12750-45821 model (Z1 terminals) - if you need UPG UB12750-45822 (photo below), before purchasing the battery check actual data for that model (again, they are practically the same, but just in case...).

UPG UB12750-45821 features physical dimensions of (L x W x H) 10.24 x 6.61 x 8.27 (9.13 with terminals) inches (~260 x 168 x 210/232 mm) and it weighs 49.1 pounds (~22 kg) - it is BCI Group 24 battery.

UPG UB12750 features a very low-self discharge rate. When the new, fully charged UPG UB12750 battery is stored at 77°F/25°C, its charge level after 3 months of storage is at 91% of full charge, after 6 months is at 82% and after 12 months of storage, it is at 64% of full charge.

So, if the UPG UB12750 battery is being stored at 77°F/25°C, be sure to recharge it after 6 months or when the charge drops down to 80% - when storing this and other similar batteries, it is highly recommended to store them in a dry and cool area, fully charge them with smart AGM battery charger and leave them connected to smart AGM battery charger/maintainer that will monitor the battery and keep it fully charged during storage.

UPG UB12750 is used for both cycle and float applications. When the UPG UB12750 battery is used for float/standby use, maximum charging voltage should be around 13.6 - 13.8 volts, and for cycle applications, maximum charging voltage should be limited to 14.5-14.8 volts.

Note: The maximum allowed bulk charge current is 22.5 Amps. Also, the battery should not be charged with 15+ volts - such charging voltage may damage the battery.

UPG UB12750 Discharging Charts

Constant current discharge features for the UPG UB12750 battery are given in the following chart - values are given in Amps, at 77°F/25°C:

Nominal 20h capacity of the UPG UB12750 is 75 Ah, but as the discharge current is increased, the actual capacity is decreased - this is typical behavior of lead-acid batteries. For example, the actual capacity of UPG UB12750 is given in the following list:

- 20h, 3.75 Amps: 75 Ah,

- 10h, 6.98 Amps: 69.75 Ah,

- 5h, 12.75 Amps: 63.75 Ah,

- 1h, 45 Amps: 45 Ah.

Note: as the battery is being discharged faster, lower end-voltage is acceptable.

Constant power discharge features for the UPG UB12750 battery are given in the following chart - values are given in watts, at 77°F/25°C:

As one can see, UPG UB12750 is able to provide 2750 watts for 5 minutes (~260 Amps) when being drained down to 9.6 volts - if you actually discharge the battery in 5 minutes, first of all, let the battery cool down a little bit and then recharge it using smart AGM battery charger.

Also, if you regularly discharge your AGM battery in 5 minutes or less, consider getting several times larger battery :)

UPG UB12750 As Standby Battery

UPG UB12750 is designed to withstand 3-5 years of use in standby applications like UPS battery, in security systems, in medical systems, and similar.

Actual standby life depends on the battery charger/maintainer that keeps the battery fully charged (again, when the battery is used for standby applications, maximum charging voltage should be around 13.6-13.8 volts) - if in doubt, it is a good practice to periodically (every few months), discharge the battery down to 70% SoC (30% DoD) and again to fully charge the battery using smart AGM battery charger with a maximum charging current not more than 22.5 Amps, preferably 15 or so Amps.

Also, it is good practice to let such an AGM battery charger equalize the battery cells.

Note: storing the battery in the area with high temperature (above 86°F/30°C and especially above 104°F/40°C) can significantly shorten its storage/operating life.

UPG UB12750 As Cycle Application Battery

When the UPG UB12750 is used as deep cycle battery, its operating life is expressed as the number of charging/discharging cycles that the battery may withstand with a certain capacity loss and it depends on the Depth of Discharge and is given in the following list:

- 100% DoD: ~200 charging/discharging cycles down to 80% of nominal capacity, ~230 charging/discharging cycles down to 60% of nominal capacity,

- 50% DoD: ~470 charging/discharging cycles down to 80% of nominal capacity, ~500 charging/discharging cycles down to 60% of nominal capacity,

- 30% DoD: ~1180 charging/discharging cycles down to 80% of nominal capacity, ~1220 charging/discharging cycles down to 60% of nominal capacity.

Note: these values are given for the battery being used at 77°F (25°C).

So, when the UPG UB12750 is used as a deep cycle battery, its operating life (number of charging/discharging cycles) may be increased by avoiding too deep discharges.

UPG UB12750 As Electric Trolling Motor Battery

UPG UB12750 is commonly used as a battery for powering electric trolling motors, especially small and medium-size electric motors on small boats, pontoon, and even kayaks.

Operating time on the single battery charge depends on the motor's current - if the current is kept below 25 Amps, one may expect even up to 2 hours of operation.

However, if some larger electric trolling motor is used, with a current draw of 50-60 Amps, one may expect 30-35 minutes of operation, with some energy left in the battery for safety reasons.

Note: If the battery is going to be used on small boats, pontoon, and kayaks, it is good practice to place the battery in the battery box that protects the battery from water splashes, sun, wind, and similar.

Such battery boxes range from simple plastic boxes to complete power centers that can be used for charging the batteries, too. Also, such power centers usually feature automatic circuit breakers, USB charging ports, and similar - if you are spending a lot of time on the water, consider one of these power centers. If not, a simple battery box will do just fine.

Long Story Short: UPG UB12750 battery is a very popular BCI Group 24 general-purpose, deep cycle battery.

If you need good, reliable, and affordable AGM 12V 75 Ah battery for your applications, and UPG UB12750 fits your needs, consider it as your next battery.

For more reviews and recommendations, feel free to check Universal Power Group UB12750 12V 75AH Sealed Lead Acid AGM Battery Amazon link (link opens in the new window).