Specifications are subject to change. See bluesea.com/P12 for current information.
The Blue Sea Systems P12 Battery Charger is dry mount device designed for use in marine applications and other harsh environments where reliability, ease of
use, and high performance are of primary importance. To this end, the P12 is designed, assembled, and tested in Bellingham, Washington, USA. Critical
components, including all electronic circuitry, are of US manufacture.
The P12 is designed to charge three electrically independent batteries or battery banks. The P12 has the unique capability to individually move each battery
out of the Absorption charging stage. This ensures batteries near their full charge do not continue to receive high constant voltages necessary in the Absorption
stage. This is optimal treatment for long battery life. Charge Coordination integrates with the Blue Sea Systems family of Automatic Charging Relays (ACR) to
force separation of the battery banks while the P12 is operational, to allow the batteries to individually exit the absorption stage. After fourteen days of
continuous Float, the charger will repeat the normal charge cycle to assure good battery health.
For reliability, the P12 has a rugged cast aluminum housing with high heat dissipating capability for minimum cooling fan run times. The electronic design has
given special consideration to operation in areas of inconsistent AC power quality. The P12 has a Power Factor Corrected nominal AC input range of 90V to
265V AC within which it will produce its full rated DC charging output. It will continue to produce reduced DC output to as low as 75V AC. After a shut down
below 75V AC or when there is interrupted switching between AC sources, like switching between generator and shore power, the P12 will automatically perform
an orderly restart.
Central to the P12’s ease of use is the large plain-language full graphics control screen capable of displaying in French, English, Italian, German and Spanish.
The plain language display enables clear communication with the operator for setting precise charging parameters and providing a broad range of easily under-
stood fault communications and operating history. An optional remote display brings much of this functionality to a secondary location away from the charger.
The P12 contains charge profiles for most batteries available today, including Flooded Lead Acid (FLA), Gel, Thin Plate Pure Lead (TPPL), and Absorbed Glass
Mat (AGM). In addition, a user configurable charge profile is available for other battery types.
The P12 has built-in safety features including: ignition protection, over and under temperature protection (sensed internally and at the batteries), DC reverse
polarity protection, DC over voltage protection, and surge and short circuit protection.
The definitions of the P12 charging stages are defined below. The charging stage LEDs on the front of the charger will indicate the current stage.
Absorption (Constant voltage)
In the Absorption charging stage the batteries complete their charging by being “topped off”. This is a less aggressive charging stage than bulk where the current going into a
particular battery bank will significantly reduce with time. The conditions for a battery bank to be considered “full” vary based on many different factors. In order for a battery
bank to leave the Absorption stage a number of different parameters must be met. The main parameters are the Absorption Timers which can be seen on
page 14. Outputs move individually from Absorption to Pre-Float. When all batteries have completed Absorption, the charger will move them into the Float stage.
Float (Constant voltage)
Float is the final charging stage for fully charged batteries. Batteries in this stage are being maintained at their defined float voltage. Typically his Float voltage
commonly has a 1.0V or greater difference from the Absorption voltage.
Pre-Float (Constant voltage)
The Pre-Float charging stage is unique to the P12. Since the size of battery banks typically vary from one output to the next, there is a need to charge each bank independently.
Once all batteries are in Absorption battery banks may finish charging at different rates. Once a battery bank has met its unique Absorption parameters the P12 Charger will
independently move it into the Pre-Float stage. Pre-Float is the initial stage to maintain a fully charged battery. Batteries in Pre-Float can have up to a .5V difference
between batteries in Absorption. Up to two outputs can be in Pre-Float simultaneously.
Bulk (Constant current)
The Bulk charging stage is the first stage in the battery charging process. It is where a majority of the charging actually takes place leaving batteries at approximately
75% to 80% of their final capacity. The goal of the Bulk stage is to drive current into the batteries quickly to increase their voltage. Once all the batteries have reached the
defined Absorption voltage then the charger will move them into the Absorption stage.
14.4V
13.9V
T I M E
Absorption
Absorption
Absorption
PreFloat
Bulk
13.2V
Battery 1
Battery 2
Battery 3
PreFloat
Float
Example of Flooded Lead Acid Battery
14.4V
T I M E
Absorption
Bulk
13.2V
Battery 1
Battery 2
Battery 3
Float
Forced Absorption: A period when batteries are potentially over charged.
Example of Flooded Lead Acid Battery
Absorption
Absorption
Forced Absorption
Forced Absorption
Conventional Three Stage Battery ChargingFour Stage Battery Charging
Four Stage Battery Charging
P12 Battery Charger Overview3
7521 AND 7522 BATTERY CHARGERS
P12
7521 AND 7522 BATTERY CHARGERS