Can I connect the charger to only one battery?
What do I do with the unused terminals?If one battery bank should be connected please use the terminal DC1.
On a DOLPHIN, you will NOT need to jumper the unused positive terminals to one of the positive terminals that you are using so that the charger will “read” a battery on each lead.
Where can I mount the charger?Anywhere except gas engine room as the unit is not ISO 8846 certified. Due to high level of electronic performance the DOLPHIN battery charger can provide full power without derating up to 65 degrees C.
Can my charger be left on for an extended period of time?Yes without problem. On DOLPHIN PRO charger a specific winterizing charging program is available in order to keep-up the battery.
What charger setting do I have to use for AGM batteries?DOLPHIN charger includes different battery specification program. On DOLPHIN PRO up-to 10 charging programs are available. For example in case of AGM batteries select the AGM charging programs.
Can I charge a lead-acid battery and a gel-cell battery together?Our chargers charge and float lead-acid batteries at a different voltage than gel-cell batteries. You should not mix battery types because you are going to compromise a battery if you charge it at the wrong setting.
How long will it take to charge my batteries?The following equation will give you a good idea of how long it will take to charge batteries.
Total Amp Hour capacity of the batteries
Total amperage output of charger
= Total Hours To Charge Batteries
Example: 100 amp hour battery / 10 amp charger = 10 hours
If you drain your battery half-way (50%) then you would need to put 50 amps back into it. Based on the above equation it would therefore take you 5 hours to charge the battery.
If you have more than one battery, you will have to add up the amp hour capacity of all the batteries and then divide it by the total amp output of the charger to get the charge time.
How areEach of these terms describes the same function of the charger where the charger temporarily elevates the battery’s voltage above the float level. There are different uses for elevated charge voltage, as shown below:
Commonly understood meaning of the term
- Equalize : Periodic "topping up" of battery capacity, and correct cell capacity differences
- Boost : Can refer to "equalize," "fast charge," and sometimes both
- Fast charge : Faster recharge of a discharged battery
What doesAll batteries, even those assembled into unitized blocks, are all built of individual battery cells connected in series to obtain the required DC voltage. Like all manufactured products, there is variation between the capacities of each cell in the battery. As the battery ages this variation increases. Since the battery is a chain of cells that is only as strong as the weakest link some scheme is required to ensure that all cells stay at peak capacity.
A scheme called "equalizing" is commonly used in both lead-acid and nickel cadmium batteries. Equalizing temporarily elevates the charging voltage of the entire battery string above the normal "float" voltage. The elevated charging voltage allows all cells, including the weak ones, to accept more current from the charger than they would at float voltage. A consequence of the elevated equalize voltage is that all cells in the battery are overcharged. This is acceptable for short periods provided the battery has sufficient electrolyte.
Overcharging greatly increases the rate at which the water in battery electrolyte is electrolyzed into oxygen and hydrogen gas. Since low electrolyte level will permanently damage the battery it is important to limit when, and for how long, the battery is charged at the equalize voltage.
What isBatteries, like all electrical conductors, suffer from resistance in their conductive metals. Ohm’s law says that resistance increases in proportion to current flow through the battery (or any other imperfect conductor). This means that the more amperes of charge we attempt to apply to the battery the more will be lost due to internal heating.
"Fast charging" temporarily increases the charger’s output voltage to compensate for the battery’s internal resistance. This allows the battery to continue accepting maximum current from the charger for a longer time – instead of reducing its charge acceptance early as it would if charged at normal float voltage.
What is the correct charging voltage?The value of both float and equalize/boost/high rate voltages is determined by the battery manufacturer, and depends on the chemistry and construction of the battery. Deviating from the recommended values, except where needed to adjust for temperature, will under or overcharge the battery – both of which will reduce the battery’s life and performance.
DOLPHIN charger includes different battery specification program. On DOLPHIN PRO up-to 10 charging programs are available. For example in case of AGM batteries select the AGM charging programs.
Do Dolphin chargers offerYes. Most DOLPHIN chargers employ an automatic system that provides four distinct charging phases. This provides providing the fast recharge and low possible water consumption.
Constant current phase: Upon startup the charger operates at maximum possible output in the fast charge mode.
High-rate taper charge phase: The charger stays at the fast charge voltage level while battery current acceptance falls to 75% of the charger’s rated output.
Finishing charge phase: The charger switches to the lower voltage float setting and completes the battery charge. Charger current continues to taper off to near zero as the battery charge reaches 100%.
Maintaining charge phase: The charger supplies only the very few milliamps required by the battery to maintain full charge. This small float current prevents battery self-discharge.
When is battery temperature compensation needed? How important is it?It is well known that all storage batteries – vented or VRLA lead acid or nickel cadmium – require different charging voltage at different temperatures. When cold, the battery requires higher than normal charge voltage in order to deliver maximum possible performance. When warm, charging voltage must be reduced to prevent overcharging and consequent loss of electrolyte.
When the battery is located in a well-controlled environment temperature compensation adds little value. In contrast, temperature compensation is absolutely essential when batteries are located in outdoor cabinets or other areas subject to extremes of temperature. These facts illustrate the value of temperature compensation:
- When a battery that is 32 degrees C / 90 degrees F in temperature is charged at the correct voltage for 10 degrees C / 50 degrees F it will be boiled dry in three months.
- When a battery -7 degrees C / 20 degrees F is charged at the correct voltage for 10 degrees C / 50 degrees F it will fail to charge – and thus fail to deliver its specified performance.
Using a charger equipped with automatic temperature compensation can prevent both of these problems.
Is it alright to run a 50 Hz charger on 60 Hz AC and vice-versa?Yes without any problem, exept on the Dolphin Premium 10A and 15A where there is a manual switchover. This will not affect the performance of your DOLPHIN charger.
What is Microprocessor-Controlled Charging?A microprocessor-controlled battery charger is designed to provide fast, safe and efficient charging to a wide variety of battery types and sizes. Advanced microprocessor-controlled algorithms monitor the charging process to avoid battery damages caused by overcharging. Simply put, the charger collects information from the battery and adjusts the charge current and voltage based on this information. This allows the battery to be charged quickly, correctly, and completely when using a microprocessor-controlled battery charger. Because of this, fast charging does not have negative effects on the capacity of the battery and on battery cycle-life. The multi-phase charging process ensures that each battery gets the power it needs in a manner that is best for the health of the battery ensuring that all of the energy is properly absorbed by the battery whether it’s a Conventional, AGM, Gel Cell, Marine or Deep Cycle battery. Microprocessor-controlled battery chargers can remain connected to the battery indefinitely and will not overcharge or damage it. Microprocessor controlled battery chargers are faster, safer and certainly more efficient than "old school" transformer type battery chargers.
What is Automatic Charging?When an automatic charge is performed, the charger stops charging and switches to the Maintain Mode (Float-Mode Monitoring) automatically after the battery is fully charged. Automatic chargers are more forgiving on the battery than manual chargers but are not designed for indefinite or maintenance use. Automatic chargers use a cycling process (see Maintain Mode) to prevent overcharging the battery.
What is Maintain Mode?When the CHARGED LED is lit; the charger has started Maintain Mode. In this mode, the charger keeps the battery fully charged by delivering a small current when necessary. If the battery voltage drops below a preset level, the charger will go back in to Charge Mode until the battery voltage returns to the full charge level, which at this point the charger will return to Maintain Mode. The charger automatically switches between Charge Mode and Maintain Mode as necessary. The CHARGED LED will cycle on when the battery is at full charge and off when the voltage drops below a preset level and the charger goes into Charge Mode. The cycle will continue, and the CHARGED LED will stay on for longer periods of time as the battery becomes more fully charged. The voltage is maintained at a level determined by the BATTERY TYPE selected.
What is multi-stage charging?The term multi-stage charging means that the voltage differential changes throughout the charging cycle. We’ll use the typical 12-volt liquid lead acid battery as an example.
The first charge stage would be the BULK stage which gets as much current into the battery as fast as possible without damage. The charger will attempt to discharge 14.4 volts at its maximum current in order to achieve the charge. Anything higher can cause heat build-up; lower will slow the charge rate. With this in mind, once the voltage differential equalizes (battery voltage meets the charger voltage, approximately 85% charged), we enter the absorption stage.
In the absorption stage, the charger maintains the 14.4 volts, but the current will slowly drop as the battery increases in resistance (caused by an increase in charge level). Absorption stage will top off the battery state of charge. Once the battery is “full”, the charger will drop its voltage to 13.4 and transition to the float stage. The float voltage level is high enough to keep the battery “full”, even if DC loads are turned on, but low enough to prevent persistent gassing of the battery which can cause long term damage.
Why do some chargers have a battery temperature sensor?The examples I have used are for the absolute ideal scenarios using a liquid battery, a proper sized charger, and a moderate temperature.
However, the battery’s reactions to voltage differential changes with different temperature levels. When a battery is warmer, it has an easier
time accepting current, but when it’s colder, it has a higher resistance to current. So, more complex chargers utilize a battery temperature sensor to determine the ability of the battery to accept a charge and will adjust the voltage (higher voltage when cold, lower voltage when warm) to give an optimum charge, and to regulate the temperature of the charging battery. The voltage difference is minimal (typically .03 volt for every degree variance from moderate temperature), but makes a difference in the battery’s longevity.
How large of a charger should I have?With limited knowledge of battery charging, one might believe that a 400Ah battery bank, charged by a 400-amp charger, should fully charge from a completely discharged status in about an hour.
However, a charger that large would cause so much heat build-up in the battery that it would be completely destroyed before too long.
On the other side of the spectrum, a 5-amp charger would not damage the battery, but would take over three days to charge! So … what’s the optimum charger? The general rule of thumb is C/5, or Capacity (in amp-hours) divided by 5. So an 80-amp charger is the right size for a 400Ah battery bank (400/5=80). When rounding is necessary, always round down because your battery bank will degrade over time and your C/5 rule will eventually meet.
How do I match my battery to my charger?Actually, in a new installation, the battery should be specified first, before even considering the charger. Why? If the charger is determined first, it may limit your battery choices. On the other hand, there are so many charger types that you can always find one (or stackable charger units) to match your battery bank.
First consideration is the size, next is battery chemistry. If you decide
on a gel battery or an AGM, ensure your charger has the algorithm to match the battery type, and the temperature compensation to effectively charge the bank.
Another consideration is input voltage. If you plan on using the charger in a worldwide environment, ensure you select a charger that can operate on a worldwide voltage range. A US-only charger (120V 60Hz input) would certainly be damaged by plugging into European (230V 50Hz) power. However, DOLPHIN Charger can take a wide window of input voltages and still function as designed.
How do I know if my battery needs charging or not?Most people use battery voltage as an indicator as to the battery state of charge. This gives a broad indication, but is far from accurate. For instance, a battery under little loads that measures 11.5 volts would be considered heavily discharged. However, a battery under heavy loads measuring 11.5 volts would rebound to a much higher voltage when the load turns off. The only truly accurate way to confirm the state of charge is to measure total amperage being drawn from -- and charged back into -- the battery. The best device to use is a shunt-based battery monitor which measures the amperage and uses voltage readings and complicated equations to
accurately display a state of charge of the battery. Once the monitor
shows the battery around 50% charged, it’s time to charge your battery bank (batteries should not be discharged below 50% State of Charge).
What should I consider when planning a charger installation?The first and most important thing to consider is the location of the
charger. Higher voltage AC travels better over long distances, where the DC does not. Due to this situation, the charger should be mounted as close to the battery as possible. If the AC source is 9 meters / 30 feet from the battery, your voltage drop of 9 meters / 30 feet of AC wiring will be much less significant than the voltage drop of 9 meters / 30 feet of DC wiring.
Next on the priority list for consideration is the charger size. Your
maximum charger amperage should be 20% of your battery bank size (in amp-hours). If you have a large bank, you can use one of the chargers on the market that are ‘stackable’. This means that you can install two 40-amp chargers to get 80 amps of charge. The most effective way is to have the chargers synchronize (or stack) with each other so the charge algorithm works efficiently. This prevents one charger from assuming a fully charged battery because it mistakenly ‘reads’ the voltage of the other charger.
Next you must consider the future of the system. If you plan to
eventually add an inverter, you might consider the benefits of an
inverter/charger combination unit. Since an inverter and a charger
share many of the same components, installing a combination unit in your system allows cost savings realized from duplicating redundant components. When using separate units, one will always be idle while the other is in use. So for hardware weight and size efficiencies, a combination unit is recommended.
What is Power Factor Correction, and how is it important?While challenging to explain, Power Factor Correction (PFC) and PFC
chargers require less incoming energy to provide the same output of
their non-PFC counterparts. PFC is measured by how efficiently the
AC sine wave is used. In a non-PFC charger, the circuitry has a delayed reaction to the alternating current in the incoming sine wave. When PFC is utilized, the circuitry ‘anticipates’ the rise in voltage, eliminates the delay and allows the circuitry to use the incoming AC more effectively.
Here’s an example to try and clarify this concept. When two 80-amp
chargers were compared at full output, the non-PFC charger was drawing over 14 amps where the PFC charger was just over 9 amps.
The end result of the PFC advantage is more amperage available for the other AC devices installed in the system