As more South Africans turn to solar power and backup energy solutions to combat load shedding and rising electricity costs, choosing the correct deep-cycle battery is crucial for ensuring reliable and long-lasting power storage. But with so many options available—AGM, gel, lead-carbon, lithium, and tubular batteries—which is best suited for your needs?
Deltec Energy Solutions specialises in providing high-quality solar and backup power solutions. In this guide, we’ll break down the different types of deep-cycle batteries and help you make an informed decision.
What Is a Deep Cycle Battery?
A deep-cycle battery is designed to provide steady power over an extended period, making it ideal for solar energy storage and backup power. Unlike car batteries, which deliver short bursts of high current, deep-cycle batteries can be discharged and recharged (cycled) multiple times without significant performance loss.
Types of Deep Cycle Batteries for Solar and Backup Power
1. AGM (Absorbent Glass Mat) Batteries
Pros:
- Maintenance-free (sealed, no water refilling needed)
- Spill-proof and vibration-resistant
- Fast charging capability
- Performs well in cold temperatures
Cons:
- Lower lifespan compared to lithium
- Sensitive to overcharging
Best for: Backup power systems, UPS, and off-grid solar applications where cost and maintenance-free operation are essential.
2. Gel Batteries
Pros:
- Longer lifespan than AGM (up to 5-7 years)
- Excellent deep discharge recovery
- Completely sealed and maintenance-free
- Performs well in high temperatures
Cons:
- Slower charge rate compared to AGM and lithium
- More expensive than AGM
Best for: Solar energy storage in warmer climates or areas where battery maintenance is complex.
3. Lead-Carbon Batteries
Pros:
- Extended cycle life compared to AGM and gel
- High charge acceptance rate (better performance in solar applications)
- Resistant to sulfation (a common battery failure issue)
Cons:
- More expensive than traditional AGM and gel batteries
- Bulkier than lithium
Best for: High-demand solar applications where longevity and reliability are crucial.
4. Tubular Batteries
Pros:
- Exceptional lifespan (up to 10+ years)
- High efficiency and deep discharge capabilities
- Ideal for long-duration power storage
Cons:
- Requires maintenance (water refilling)
- Heavier and bulkier than AGM or lithium
Best for: Heavy-duty solar storage where long life and deep cycling capabilities are needed.
5. Lithium-Ion Batteries
Pros:
- Most extended lifespan (up to 15 years)
- Lightweight and compact
- Fast charging and higher efficiency
- Maintenance-free
- Higher depth of discharge (DoD) without performance loss
Cons:
- Higher initial cost
- Requires a Battery Management System (BMS) for safety
Best for: Premium solar energy storage where high efficiency, longevity, and zero maintenance are key factors.
Which Deep Cycle Battery Is Best for You?
| Battery Type | Best For | Lifespan | Maintenance |
| AGM | Backup power, off-grid solar | 3-5 years | No |
| Gel | High temperatures, deep discharge use | 5-7 years | No |
| Lead-Carbon | Solar applications with frequent cycling | 5-10 years | No |
| Tubular | Long-duration storage, heavy usage | 10+ years | Yes |
| Lithium | Premium solar systems, efficiency-focused users | 10-15 years | No |
If you need a cost-effective backup battery for load shedding, an AGM or tubular battery may be the right choice. If you want maximum efficiency and lifespan, lithium-ion is the best investment.
Need Help Choosing the Right Battery?
Deltec Energy Solutions offers a wide range of solar and backup power batteries designed to suit different budgets and energy needs. Whether you need a budget-friendly AGM for occasional load shedding or a high-performance lithium system for long-term solar energy storage, we’ve got you covered.
Contact Us Today!
Website: www.deltecenergysolutions.co.za
Phone: 011 864 7930
Email: sales@deltec.co.za