What Is a Deep Cycle Battery?
A deep cycle battery is designed to be regularly discharged to 50–80% of its capacity and then recharged — unlike a car starting battery, which delivers brief high-current bursts and stays near full charge. This fundamental difference in design determines which applications each battery type suits.
Standard starting batteries use thin positive plates with a large surface area — ideal for delivering 300–600A for engine cranking. Deep cycle batteries use thick solid plates with denser active material — designed to withstand repeated deep discharge without degrading rapidly.
Key Differences: Deep Cycle vs Starting Battery
| Feature | Deep Cycle Battery | Starting Battery (Car Battery) |
|---|---|---|
| Plate design | Thick solid/pasted plates | Thin expanded metal plates |
| Active material density | High | Low |
| Discharge depth | Designed for 50–80% DoD | Designed for <5% DoD |
| Cranking amps (CCA) | Low to moderate | Very high (300–1000A) |
| Cycle life | 600–1,500 cycles | Not rated for cycling |
| Float life | 8–15 years | 3–5 years |
| Typical applications | Solar, traction, marine, UPS | Engine starting |
Using a starting battery for deep cycle applications — or vice versa — causes premature failure and is a common and costly mistake.
Types of Deep Cycle Lead-Acid Batteries
Flooded Lead-Acid Deep Cycle
The original deep cycle technology. Requires periodic watering maintenance but offers the lowest cost per cycle when properly maintained.
| Specification | FOB Price (CNY) | Best Application |
|---|---|---|
| 6V 200Ah deep cycle | ¥320–480 | Golf carts, marine |
| 6V 225Ah deep cycle | ¥380–560 | Golf carts, solar |
| 12V 100Ah deep cycle | ¥280–420 | Small solar, buffer storage |
| 12V 200Ah deep cycle | ¥480–720 | Solar storage, industrial |
| 48V 200Ah (4×12V) | ¥1,200–1,800 | Forklifts, EVs |
AGM Deep Cycle (VRLA)
Absorbed Glass Mat batteries are sealed, maintenance-free, and offer better vibration resistance than flooded units. More expensive upfront, but no maintenance cost over life.
| Specification | FOB Price (CNY) | Best Application |
|---|---|---|
| 12V 65Ah AGM deep cycle | ¥180–280 | UPS backup, solar buffer |
| 12V 100Ah AGM deep cycle | ¥280–420 | UPS, solar, telecom |
| 12V 150Ah AGM deep cycle | ¥380–580 | Commercial solar, marine |
| 12V 200Ah AGM deep cycle | ¥520–780 | Large UPS, industrial solar |
Tubular Gel OPzV Deep Cycle
The premium deep cycle option. Gel electrolyte provides the best PSOC performance and highest cycle life of any lead-acid technology.
| Specification | FOB Price (CNY) | Best Application |
|---|---|---|
| 2V 200Ah OPzV | ¥600–900 | Commercial/industrial solar |
| 2V 500Ah OPzV | ¥1,200–1,800 | Utility-scale solar storage |
| 2V 1000Ah OPzV | ¥2,200–3,200 | Telecom, grid storage |
How to Choose: A Practical Decision Framework
Choose flooded deep cycle when:
- Budget is the primary constraint
- A maintenance team is available for quarterly watering
- Battery will be discharged to 50–80% DoD daily
- Application is off-grid solar with long design life
Choose AGM deep cycle when:
- Zero maintenance is required
- Installation is indoors or in a confined space
- Battery needs to be installed in any orientation
- Application involves frequent partial discharges with occasional deep cycles
Choose OPzV tubular gel when:
- Batteries will be subjected to partial state of charge (PSOC) operation
- Ambient temperatures regularly exceed 30°C
- System design life exceeds 10 years
- Total cost of ownership is the key metric — not upfront cost
Understanding Cycle Life: What the Numbers Really Mean
Battery manufacturers state cycle life at specific test conditions. Real-world performance depends on how your actual use matches those conditions.
| Battery Type | Rated Cycles (50% DoD) | Realistic Cycles (80% DoD, PSOC) |
|---|---|---|
| Flooded deep cycle | 600–800 | 300–450 |
| AGM deep cycle | 700–900 | 350–500 |
| OPzV tubular gel | 1,200–1,500 | 800–1,000 |
A battery rated at 1,000 cycles at 50% DoD tested under ideal lab conditions will deliver fewer cycles in a real-world solar installation where PSOC operation is the norm.
Common Mistakes When Buying Deep Cycle Batteries
Mistake 1: Buying a car starting battery instead of a deep cycle battery
Starting batteries cannot handle deep cycling — they will fail within months in solar or traction applications.
Mistake 2: Comparing prices without comparing cycle life
A ¥400 battery that lasts 400 cycles costs ¥1.00 per cycle. A ¥700 battery that lasts 1,200 cycles costs ¥0.58 per cycle.
Mistake 3: Ignoring the battery’s C20 vs C5 capacity rating
Battery capacity is stated at a specific discharge rate. A 200Ah battery rated at C5 may show 180Ah at C20. Always compare batteries at the same discharge rate.
Mistake 4: Not verifying PSOC performance for solar applications
Standard cycle test data (IEC 60896-21) does not reflect real-world solar operation. Ask for PSOC cycle test data.
CHISEN Battery Deep Cycle Range
CHISEN Battery manufactures the complete range of deep cycle lead-acid batteries:
- Flooded EVF deep cycle series: 6V, 12V, 48V configurations, 150–400Ah
- AGM VRLA deep cycle series: 12V, 24V, 48V configurations, 40–250Ah
- OPzV tubular gel series: 2V single cells, 100–3000Ah
- Custom voltage configurations: 24V, 36V, 48V, 60V, 72V, 80V systems built to specification
- Certifications: CE, ISO9001, UKAS, TUV Rheinland
- MOQ: 20 units for standard specs; custom configurations from 50 units
Request specifications and FOB pricing for your application:
📧 jack@chisen.cn | WhatsApp: +86 131 6622 6999 | www.chisen.cn
