Crown CR-350 350Ah 6VDC Deep Cycle Flooded Lead Acid Battery

Frequently Asked Questions

What is the Crown CR-350 battery?
The Crown CR-350 is a 6VDC deep cycle flooded lead acid battery rated at 350Ah at the 20-hour rate. It is designed for repeated charge and discharge applications such as solar energy storage, renewable energy systems, backup power, RVs, marine equipment, electric vehicles, floor machines, and industrial equipment.

Is the Crown CR-350 a good choice for an off-grid solar system?
Yes. The Crown CR-350 is designed for deep cycle use and provides 350Ah of capacity at the 20-hour rate. It can be used in off-grid solar battery banks where flooded lead acid batteries are appropriate and regular maintenance can be performed.

How much energy can the Crown CR-350 store?
The Crown CR-350 provides approximately 2.04 kWh of rated energy at the 20-hour rate. Actual usable energy will vary based on discharge rate, depth of discharge, temperature, battery condition, and the way the battery bank is operated.

How many Crown CR-350 batteries are needed for a 12VDC, 24VDC, or 48VDC solar battery bank?
Because the Crown CR-350 is a 6VDC battery, common series configurations are:

• Two Crown CR-350 batteries in series for a 12VDC battery bank
• Four Crown CR-350 batteries in series for a 24VDC battery bank
• Eight Crown CR-350 batteries in series for a 48VDC battery bank

Additional parallel strings can be used when more amp-hour capacity is needed. The final battery-bank size should be based on daily energy use, backup requirements, inverter load, solar production, and allowable depth of discharge.

What charging settings should be used for the Crown CR-350?
Use a solar charge controller configured for flooded lead acid batteries and follow Crown's recommended charging requirements for the specific installation. The charger must be compatible with the total battery-bank voltage. Avoid chronic undercharging and unnecessary overcharging because improper charging can reduce battery performance and service life.

Does the Crown CR-350 require regular watering?
Yes. The Crown CR-350 is a flooded lead acid battery and requires periodic electrolyte inspection and watering. Use distilled or de-mineralized water and maintain the electrolyte at the proper level. Watering frequency depends on cycling, charging, temperature, and battery age.

When is the best time to add water to the Crown CR-350?
Watering should generally be performed after charging. If the electrolyte is below the top of the plates, add enough distilled or de-mineralized water to cover the plates before charging, then complete the watering procedure after charging. Avoid overfilling the cells.

How can I maintain the Crown CR-350 for solar use?
Regular maintenance should include checking electrolyte levels, keeping the battery and terminals clean and dry, inspecting cables and connections, and monitoring charging performance. The battery should also remain properly ventilated and installed upright.

Does the Crown CR-350 need ventilation?
Yes. Flooded lead acid batteries can release hydrogen gas during charging. Install the Crown CR-350 in a properly ventilated location and keep it away from sparks, flames, cigarettes, and other ignition sources.

Crown Battery Comparison

How does the Crown CR-350 compare with the Crown CR-330?
The Crown CR-350 and Crown CR-330 are both 6VDC Group 902 deep cycle flooded lead acid batteries with the same listed dimensions. The Crown CR-350 provides 350Ah compared with 330Ah for the Crown CR-330, increasing rated 20-hour energy storage from approximately 1.92 kWh to 2.04 kWh. The Crown CR-350 is also slightly heavier, making it a better choice when additional capacity is more important than minimizing battery weight.

What is the difference between the Crown CR-350 and Crown CR-370?
The Crown CR-350 and Crown CR-370 are both 6VDC deep cycle flooded lead acid batteries, but they use different BCI group sizes. The Crown CR-350 is a Group 902 battery rated at 350Ah, while the Crown CR-370 is a Group 903 battery rated at 370Ah. The Crown CR-370 provides approximately 2.15 kWh of rated 20-hour energy storage compared with 2.04 kWh for the Crown CR-350, but it is also larger and heavier. The Crown CR-350 may be preferable when its Group 902 footprint fits the battery compartment.

Solar Application & Battery Life

How deeply should I discharge the Crown CR-350 in a solar system?
For regular solar cycling, avoiding unnecessary deep discharges can help extend battery life. A properly sized battery bank with sufficient capacity for the expected daily load can reduce the need for excessive discharge.

How long can the Crown CR-350 last in a solar application?
There is no single lifespan that applies to every Crown CR-350 installation. Service life depends on depth of discharge, charging, temperature, watering, maintenance, cycling frequency, and other operating conditions. Using shallower daily cycles and maintaining proper charging and electrolyte levels can help support longer service life.

How does temperature affect the Crown CR-350?
Temperature affects flooded lead acid battery performance and service life. Cold conditions can reduce available capacity, while prolonged exposure to high temperatures can accelerate battery aging. Proper ventilation and temperature management are important in solar battery installations.

Can the Crown CR-350 be used for RV, marine, and backup power applications?
Yes. The Crown CR-350 is a deep cycle battery that can be used in applications requiring repeated charge and discharge cycles, including RVs, marine systems, backup power, and other equipment. The battery-bank voltage and available capacity must be matched to the specific application.

Is the Crown CR-350 maintenance-free?
No. The Crown CR-350 is a flooded lead acid battery and requires periodic electrolyte inspection and watering. Customers who want less routine maintenance may consider AGM or other sealed battery technologies, but the replacement must be compatible with the system's charging equipment and electrical requirements.