Battery Equivalents and Replacements

Trojan T-1275 GC12 Deep Cycle Flooded Lead Acid Battery

Trojan T-1275 is a lead-acid flooded 12V 150Ah deep cycle battery commonly used in electric vehicles, off-the-grid applications, backup systems, security systems, trolling motor battery and similar.

Trojan T-1275 battery is still a very popular deep cycle battery, thanks to its performance and acceptable price, despite AGM/Gel-Cell lead-acid and lithium batteries being more and more popular.

Published: October 6, 2021.

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Trojan T-1275 Battery Features and Specifications

Trojan T-1275 battery belongs to the BCI GC12 Battery Group which is one of the most popular battery groups for use in electric vehicles like golf carts, forklifts, and similar.

Also, it is a very popular choice for larger battery packs in off-the-grid applications, where it is used to make 12V, 24V, 36V, 48V, or battery packs with even larger voltages.

Trojan T-1275 battery feature physical dimensions of 12.96 x 7.13 x 11.13 inches (329 x 181 x 283 mm) and weighs 85 pounds (~38.5 kg).

When the Trojan T-1275 battery is compared with the deep cycle lithium batteries, it is pound-for-pound, 2-3x heavier than the lithium batteries of a similar capacity.

But, when the Trojan T-1275 battery is compared with deep cycle and dual-purpose AGM and Gel-Cell batteries, it is some 25-40% lighter.

Trojan T-1275 battery features 6 (six) flooded/wet cells, a nominal voltage of 12V, and a nominal (20h) capacity of 150Ah.

The actual capacity of the battery depends on the discharge time/current:

- 5h capacity: 120 Ah (24A),

- 10h capacity: 134 Ah (13.4A),

- 20h capacity: 150 Ah (7.5A),

- 100h capacity: 166 Ah (1.66A).

Similarly, the Trojan T-1275 battery features a Reserve Capacity of 280 minutes - it is able to provide 25 Amps for 280 Amps.

Also, the battery is able to provide 56 Amps for 102 minutes, and 75 Amps for 70 minutes.

Note: all these values are given for the new, fully charged Trojan T-1275 battery @77°F (25°C).

Trojan T-1275 battery should be mounted vertically in a well-ventilated area.

Also, the battery features a relatively low self-discharge rate, but when the battery is stored for a longer period of time, it should be watered properly, fully charged, and stored in a cool, ventilated area. And when the battery charge drops below 70-80% of nominal charge, cell water levels should be checked, after which the battery should be fully recharged.

When the Trojan T-1275 battery is properly maintained, it can last 5-8 years in a typical golf cart application.

Similarly, in many off-the-grid, automotive and light-industrial applications, the Trojan T-1275 battery can outperform most sealed AGM and Gel-Cell batteries, but it MUST be maintained properly - for example, water levels should be checked every 2-4 weeks.

Note: For exact maintenance procedures, check the instructions/Owner's Guide that comes with the battery.

State of Charge (SoC%) of the Trojan T-1275 battery can be verified by measuring the specific density ("specific gravity") of electrolyte in each cell, by checking the voltage of each cell, or simply by checking the voltage of the whole battery.

Note: Since this is a wet/flooded battery, its cells should be regularly equalized as recommended by the manufacturer - this prevents imbalances among the battery cells and prolongs the battery lifetime.

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How to Charge Trojan T-1275 Battery?

Trojan T-1275 battery can be recharged as part of the battery pack or as an individual battery.

The charging current should be kept at most at 20-25 Amps, although the battery can withstand even stronger charging currents which can shorten the charging time but can also shorten the battery lifetime.

When the battery is charged at 77°F (25°C), the voltages should be:

- Bulk Charge: 14.82V,

- Float Charge: 13.50V,

- Equalize Charge: 16.20V.

Again, equalization of the cells and charging with gassing (to avoid stratification) are important for proper maintenance of Trojan T-1275 and similar wet/flooded batteries.

Note: Equalization means that the voltage/capacity of the cells in the battery are equalized. Stratification or "Acid Stratification" is the accumulation of sulfuric acid at the bottom of the battery cells, leading to imbalances within the individual cells and shorter battery life.

When charging Trojan T-1275 battery the use of a smart, microprocessor-controlled wet/flooded lead-acid battery charger with temperature compensation is highly recommended - or a similar smart AGM battery charger with wet/flooded battery charging mode.

Long Story Short: The Trojan T-1275 battery is an excellent lead-acid battery in terms of its performance, but it is a wet/flooded battery and the water levels should be checked regularly.

trojan t 1275 mAlso, periodic equalization and cells gassing are also part of the maintenance procedures.

And the battery MUST be positioned vertically and placed in a well-ventilated area.

If You are looking for a durable deep-cycle lead-acid battery and You don't mind all the maintenance procedures of the Trojan T-1275 battery, and it fits your needs, consider it as your next deep-cycle lead-acid battery.

And if You are looking for a GC12 wet/flooded lead-acid battery, the Trojan T-1275 battery is one of your best possible choices.

For more reviews and recommendations, feel free to check the Trojan T-1275 Flooded Deep-Cycle Lead-Acid Battery Amazon link (link opens in the new window).