Frequently Asked Questions
What is the Crown 27MDC battery?
The Crown 27MDC is a 12VDC marine deep cycle flooded lead acid battery with a rated capacity of 95Ah. It is designed for repeated charge and discharge use and can serve marine, RV, renewable energy, solar, and other deep cycle applications.
Is the Crown 27MDC a good choice for solar energy storage?
Yes. The Crown 27MDC can be used in solar systems designed around flooded lead acid batteries. It is especially useful for smaller off-grid systems where a 12VDC battery and Group 27 meet the installation requirements.
How much energy can the Crown 27MDC store?
The Crown 27MDC has a rated capacity of 95Ah. The amount of energy that can actually be used by a solar system depends on factors such as discharge rate, depth of discharge, temperature, battery condition, and system losses.
Can the Crown 27MDC be used in a 24VDC or 48VDC solar system?
Yes. Multiple Crown 27MDC batteries can be connected in series to increase the battery-bank voltage.
- Two Crown 27MDC batteries in series create a 24VDC battery bank.
- Four Crown 27MDC batteries in series create a 48VDC battery bank.
Parallel battery connections can be added when additional amp-hour capacity is needed, but the complete bank should be designed with properly matched batteries, cables, protection, charging equipment, and inverter capacity.
Charging & Maintenance
What charging settings should be used for the Crown 27MDC in a solar system?
Use a solar charge controller configured for a flooded lead acid battery and follow Crown's recommended charging requirements for the application. The charging system should be matched to the voltage and capacity of the complete battery bank.
Does the Crown 27MDC require watering?
Yes. The Crown 27MDC uses flooded lead acid technology and requires periodic electrolyte inspection and watering. Distilled water should be used when water needs to be added.
When should water be added to the Crown 27MDC?
Water should normally be added after the battery has been fully charged. If the electrolyte level is too low before charging, add only enough distilled water to cover the exposed plates, then complete charging before bringing the electrolyte to the proper level.
Can the Crown 27MDC be used without ventilation?
No. Flooded lead acid batteries can release hydrogen gas during charging. The battery should be installed in a properly ventilated location and kept away from flames, sparks, cigarettes, and other ignition sources.
What maintenance helps keep a Crown 27MDC performing properly?
Regular service should include checking electrolyte levels, inspecting the battery case and venting components, keeping the battery and terminals clean and dry, checking cable connections, and confirming that the charging system is operating correctly.
Crown Battery Comparison
How does the Crown 27MDC compare with the Crown 24MDC?
The Crown 27MDC provides more rated capacity than the Crown 24MDC. Both are 12VDC flooded marine deep cycle batteries, but the Crown 27MDC is rated at 95Ah compared with 75Ah for the Crown 24MDC. The 27MDC is a better choice when additional storage is needed and its Group 27 footprint fits the installation.
|
Specification
|
24MDC
|
27MDC
|
|
Voltage
|
12VDC
|
12VDC
|
|
Capacity (20 Hr)
|
75Ah
|
95Ah
|
|
Reserve Capacity
|
100 min @ 25A
|
140 min @ 25A
|
|
Dimensions
|
10.19 x 6.81 x 9.5 in (25.88 x 17.30 x 24.13 cm)
|
12.95 x 6.81 x 9.38 in (30.63 x 17.30 x 23.83 cm)
|
|
Weight
|
38 lbs (17.2 kg)
|
53 lbs (24.0 kg)
|
|
Terminal Type
|
Dual post/Stud combination
|
Dual post/Stud combination
|
What is the difference between the Crown 27MDC and Crown 31MDC?
The Crown 27MDC and Crown 31MDC are both 12VDC marine deep cycle flooded lead acid batteries. The Crown 31MDC increases rated capacity to 115Ah compared with 95Ah for the Crown 27MDC and provides a larger physical format. The 27MDC is a practical choice when its smaller Group 27 provides enough capacity for the application.
|
Specification
|
27MDC
|
31MDC
|
|
Voltage
|
12VDC
|
12VDC
|
|
Capacity (20 Hr)
|
95Ah
|
105Ah
|
|
Reserve Capacity
|
140 min @ 25A
|
180 min @ 25A
|
|
Dimensions
|
12.95 x 6.81 x 9.38 in (30.63 x 17.30 x 23.83 cm)
|
13.00 x 6.75 x 9.38 in (33.02 x 17.15 x 23.83 cm)
|
|
Weight
|
53 lbs (24.0 kg)
|
58 lbs (26.3 kg)
|
|
Terminal Type
|
Dual post/Stud combination
|
Dual post/Stud combination
|
Solar Application & Battery Life
How should the Crown 27MDC be sized for a solar application?
Battery-bank sizing should consider daily energy use, required backup time, system voltage, solar production, inverter demand, and the desired depth of discharge. The 95Ah rating provides the starting point, but the complete system should be sized rather than relying on the battery's nominal capacity alone.
How deeply can the Crown 27MDC be discharged?
The battery is designed for deep cycle use, but routinely using a large portion of its capacity can reduce service life. For solar applications, using a battery bank with enough capacity to avoid unnecessary deep daily discharges can help reduce battery stress.
Can the Crown 27MDC be used for RV and marine power?
Yes. The 27MDC is designed as a marine deep cycle battery and can provide sustained power for compatible RV and marine electrical loads. It can also be used in other systems when its electrical and physical specifications meet the application requirements.
Can the Crown 27MDC be connected to other battery models?
It is best to build a battery bank with batteries of the same model, capacity, age, and condition. Mixing different battery models or substantially different capacities can create charging and balancing differences that may reduce overall battery-bank performance.
What should I check if my Crown 27MDC is losing capacity?
Check the charging profile, charging voltage, electrolyte level, terminal connections, operating temperature, and discharge pattern. Long periods of undercharging, excessive discharge, poor connections, high temperatures, and battery age can all contribute to reduced capacity.
Read Less