Group GC2 and Group GC2H - 6 Volt Golf Cart Batteries

BCI Group GC2 and Group GC2H batteries are heavy-duty, deep cycle batteries commonly used in golf carts and other automotive applications.

Also, they are often used as deep cycle batteries in marine applications, off-the-grid applications, for powering medical and security systems, and similar.

Although they are by definition 3-cell 6V batteries, GC2 and GC2H batteries are sometimes offered as 12V batteries (mostly lithium 4-cell batteries) for building 24V, 36V, and 48V battery packs with fewer batteries.

Published: May 10, 2021.

BCI Group GC2 and Group GC2H Batteries Features and Specifications

BCI Group GC2 and Group GC2H batteries are very similar batteries, differing practically only in dimensions (L x W x H):

- Group GC2: 10 3/8 x 7 3/16 x 10 7/8 inches (10.375 x 7.1875 x 10.875 inches, 264 x 183 x 277 mm),

- Group GC2H: 10 3/8 x 7 3/16 x 11 5/8 inches (10.375 x 7.1875 x 11.625 inches, 264 x 183 x 295 mm).

Note: Groups GC2 and GC2H feature very similar physical dimensions as Groups GC8 and GC8H respectively, except that GC2 and GC2H batteries feature nominal voltage of 6V and GC8 and GC8H feature nominal voltage of 8V.

As one can see, GC2 and GC2H batteries feature the same length and width, but the GC2H group is 1 inch (25.4 mm) taller than the GC2 group.

However, in real life, many manufacturers label their batteries as 'GC2' batteries, although they are as tall as GC2H batteries - golf cart battery compartments and other similar battery compartments are "almost always" tall enough in order to accommodate GC2H batteries with some room left. And because of this "almost always", it is recommended to always check the actual size of the battery compartment and the size of batteries before ordering a new set of batteries.

GC2 and GC2H Battery Types and Chemistries

Most GC2 batteries are 3-cell 6-volt lead-acid batteries, although Lithium Iron Phosphate (LiFePO₄) batteries are also being offered as 4-cell 12-volt batteries.

Traditionally, lead-acid GC2 batteries are heavy-duty, deep-cycle wet/flooded batteries - since they are required to cycle a lot during use, they are build using heavy, thick plates which can often withstand 1000+ cycles down to 50% DoD, which is an excellent result for lead-acid batteries.

But, wet/flooded lead-acid batteries are not maintenance-free batteries and are being replaced by spill-proof, maintenance-free AGM and Gel-Cell lead-acid batteries, although wet/flooded are still being used very often.

AGM and Gel-Cell batteries are often designed to allow recombination of up to, sometimes even more than 99% of generated oxygen and hydrogen into water, and as such don't require periodical checks.

However, wet/flooded GC2 batteries generally still hold the edge regarding the number of supported charging/discharging cycles.

Lithium Iron Phosphate (LiFePO₄) GC2 batteries support 3000-4000 cycles down to 90-100% DoD and offer other benefits, including:

- much lighter battery pack (30-50% by weight, when compared with similar lead-acid battery packs), leading to weight savings and less strain on motors and batteries in general,

- faster recharging than lead-acid batteries,

- more stable output voltage,

- they are maintenance-free batteries that can be mounted in any position,

- they don't release any gasses,

- very low self-discharge rate, etc.

However, lithium batteries are initially more expensive, but they save money and effort in the long run.

Number of Required Batteries

The number of required batteries depends on the required voltage:

- 12V systems: 2 (two) 6V batteries or 1 (one) 12V battery,

- 24V systems: 4 (four) 6V batteries or 2 (two) 12V batteries,

- 36V systems: 6 (six) 6V batteries or 3 (three) 12V batteries,

- 48V systems: 8 (eight) 6V batteries or 4 (four) 12V batteries.

Note: when connecting the lead-acid batteries in series or parallel, it is highly recommended to connect the very same batteries from the same manufacturer, preferably from the same batch.

Similarly, when connecting lithium batteries in parallel and/or series, always use the very same batteries from the same manufacturer, preferably from the same batch, IF and only IF such connections are allowed and explicitly written by the manufacturer of those lithium batteries!

GC2 Batteries Comparison Chart

The following comparison chart lists some of the most popular GC2 batteries, with their most important features and specifications:

As one can see, lead-acid GC2 batteries feature a nominal voltage of 6 volts and 20h capacity in the 200-260 Ah range. Also, they are able to provide 25 Amps for up to 500 minutes and 75 Amps for up to 130 minutes.

Lithium GC2 batteries are offered as 12V batteries that feature 100-175 Ah capacity, but with new models emerging on the market rather quickly, one can expect these numbers to change very soon.

Lead-Acid vs Lithium GC2 Batteries

We have already mentioned several advantages and disadvantages of the lead-acid and lithium GC2 batteries, but we have to write one example to further explain the similarities and differences of these battery types.

In this example, we will compare 'classic' Trojan T-105 flooded lead-acid batteries with VMAX LFPGC-12175XTR lithium battery - both batteries connected in series to create 48 volts golf cart battery pack:

- number of batteries: 8 (eight) Trojan T-105, 4 (four) VMAX LFPGC-12175XTR batteries,

- weight of the battery pack: 512 lbs (~232 kg) Trojan T-105, 154 lbs (~70 kg) - weight saving 358 pounds (~162 kg),

- rated capacity @25A: ~186 Ah Trojan T-105, ~175 Ah VMAX LFPGC-12175XTR. When the current draw is increased, the actual capacity of Trojan T-105 is decreased much faster.

- rated capacity @75A: Trojan T-105 battery pack can provide 75A for 115 minutes (almost two hours) with an average power of 3.4-3.7 kW. VMAX LFPGC-12175XTR battery pack can provide 75 Amps slightly more than 2+ hours - the exact number is not provided by the VMAXTANKS.

Note: VMAX LFPGC-12175XTR can provide continuously 100A and 350A for 3 seconds, setting the maximum output power of such battery pack to ~5 kW continuously, and ~17 kW for 3 seconds.

- number of charging/discharging cycles: VMAX LFPGC2-12175XTR battery supports up to 4000 cycles down to 90% DoD (@35A, 25°C) and 6000 cycles down to 80% DoD (@35A, 25°C), while Trojan T-105 can withstand 1200 cycles down to 50% DoD and "premium line" Trojan T-105 RE can withstand 1600 cycles down to 50% DoD and 1000 cycles down to 80% DoD which are both exceptional values for the lead-acid battery.

- charging: Trojan T-105 battery pack can be recharged using any suitable lead-acid battery charger, although an intelligent battery charger with temperature compensation and wet/flooded battery charging mode is highly recommended. VMAX LFPGC2-12175XTR battery pack requires a dedicated lithium CC/CV (Constant Current/Constant Voltage) battery charger or a lead-acid battery charger with the dedicated charging mode for lithium batteries.

Note: If You are considering switching your golf cart from lead-acid to lithium batteries, check the battery charger You already have - maybe You will have to replace it as well.

As one can see, switching from lead-acid to lithium batteries can lead to some serious weight savings, extended golf cart range, and offers the battery pack that can withstand much more charging/discharging cycles. But, the price is initially higher ...

---

Long Story Short: GC2 and GC2H batteries are commonly used as heavy-duty, deep cycle batteries in marine, automotive, and light industrial applications where a strong and reliable power source is required.

Thanks to the advancements in technology, lithium GC2 batteries are slowly replacing lead-acid batteries in light vehicle applications, but lead-acid batteries are still being used thanks to their lower price (at least initially) and simplicity.

For heavy-duty applications, if the lithium batteries are too expensive, consider wet lead-acid batteries with heavy and thick plates, if their maintenance is not of an issue.

For the maintenance-free lead-acid batteries, consider AGM GC2 batteries, just be sure not to discharge them below 80% DoD, preferably not below 50% DoD.