What Is a Deep Cycle Battery?

A deep cycle battery is designed to be regularly discharged to 50–80% of its capacity and recharged repeatedly. This contrasts with starter batteries (like car batteries), which deliver brief high-current bursts. For solar systems where batteries cycle daily, deep cycle batteries are essential.

Types of Deep Cycle Batteries

Flooded Lead-Acid (FLA): Lower upfront cost but requires maintenance. Best for budget installations.

AGM (Absorbed Glass Mat): Sealed, maintenance-free, spill-proof. Limited deep cycle life. Best for UPS and emergency backup.

GEL Batteries: Sealed VRLA with silica gel. Better cycle life than AGM. Ideal for solar cycling and remote installations.

OPzV Tubular GEL — Premium: Tubular plates prevent shedding. 1,200–1,500 cycles at 80% DoD. Operating temp: -40°C to +60°C. Best for professional solar.

Understanding Depth of Discharge (DoD)

  • 50% DoD: ~2× the cycles of 80% DoD
  • 80% DoD: Standard for most solar applications
  • 100% DoD: Use only in emergencies — significantly reduces life

Battery Sizing Formula

Battery Bank (Ah) = (Daily Consumption Wh ÷ System Voltage ÷ DoD) × Days of Autonomy

Example: 8,000 Wh/day, 48V, 2 days, 80% DoD:
8,000 ÷ 48 ÷ 0.80 × 2 = 417 Ah → Round to 500Ah (CHISEN OPzV2-500)

Top 10 Questions About Deep Cycle Solar Batteries

Q1: How long do deep cycle solar batteries last?
A: OPzV tubular GEL: 8–15 years. AGM: 4–7 years.

Q2: Can I use a car battery for solar?
A: No. Car batteries are starter batteries — they fail quickly if deep cycled.

Q3: Best brand for deep cycle solar batteries?
A: Leading brands: CHISEN, Hoppecke, GNB (Exide), Trojan, Rolls. CHISEN offers equivalent quality with OEM customization at competitive prices.

Q4: Series or parallel connection?
A: Series increases voltage; parallel increases capacity. For systems over 5kWh, use 2V cells for efficiency.

Q5: Best temperature for battery storage?
A: 20–25°C. Every 10°C above 25°C roughly halves battery life.

Q6: Lithium vs lead-acid for solar?
A: Lithium offers 3,000–5,000 cycles at 3–4× the cost. For most off-grid solar, OPzV lead-acid offers the best value.

Q7: What is equalization charging?
A: Controlled overcharge to equalize cells. For flooded batteries; not needed for sealed VRLA.

Q8: 12V vs 2V battery systems?
A: 12V are pre-assembled. 2V cells allow flexible sizing and easier replacement.

Q9: Self-discharge rate?
A: AGM/OPzV: 1–3% per month. Recharge every 3–6 months.

Q10: Best DoD for solar?
A: 80% is standard. Use 50% for maximum lifespan.

CHISEN Deep Cycle Battery Range

  • OPzV Tubular GEL Series (2V): 100Ah–3,000Ah — premium solar storage, telecom, UPS
  • EVF Series (6V/12V): 32Ah–150Ah — electric vehicles, solar, industrial
  • DZF/DMF Series (12V): 12Ah–24Ah — e-bikes, solar street lighting
  • AGM VRLA Series: 7Ah–250Ah — UPS, emergency backup

All CHISEN batteries are CE, ISO9001, ISO14001, and TUV Rheinland certified.