battery charger, buyfast -

Manual for Multi function battery charger MP777

Dear all:

we have received lots of request from our clients who interesting on Battery Charger MP777. pls hv a look of the following Manual, hope you gonna hv a better understanding of this product.

thank you

User’s Manual for Multi-function Charger MP-77 


Product Introduction:

The product suits for charging lead-acid secondary cell with 17 Ah to 120 Ah rated capacity.  The charging voltage can be selected according to the actual cell voltage.

The product also has functions such as adjustable charging current and output short circuit protection.


Operation Method:

  1. Ensure that electrolyte of the secondary cell is sufficient, or else it must be replenished before charging.
  2. Clamp the red clip of the charger to the cell anode (+) and the black clip to the cathode

          (-).  Make sure that clips and electrodes are contacted well.

  1. Turn “Current Regulator” to “OFF” and select the corresponding charging voltage (6V or 12V) of the secondary cell
  2. Insert the power cord plug of the charger to commercial electricity socket and regulate the “Current Regulator” clockwise. The “Power” lamp is lit at the moment.
  3. Observe the ammeter, regulate the “Current Regulator” until obtaining the charging current you need. After charging for a period of time, the hand of the ammeter will drop to about 2A and you may regulate the “Current Regulator” several levels higher.  Repeat so until the “Current Regulator” is regulated to “10” level with the hand of the ammeter dropping to about 2A.  Then the secondary cell is fully charged.  You can also finish charging for lengthened 1 to 2 hours.
  4. When charging is finished, turn the “Current Regulator” to “OFF”, and then remove the power cord plug and cell clips.


Protection Functions:

  1. Overflow protection: when charging current exceeds 5A for a long time, the built-in protection switch will cut off the output voltage, and then “PROTECT” lamp is on and the hand of the ammeter returns to “0”. Now, the charging current must be regulated to below 5A and then press the “protection switch” button returns to charging state after 1 minute.
  2. Short circuit protection: when there is a short circuit in the wires of the red or black clip, the protection switch cuts off the output voltage in seconds. Then, “PROTECT” lamp is on, and hand of the ammeter returns to “0”.  Now, ensure power supply is cut off and charging is done after eliminating the short circuit.



  1. The charger is only allowed to be connected to the socket with earthling contact and must be used in places with excellent ventilation and protected from rain.
  2. If the supply cord damaged, it must be replaced by the manufacturer, its service agent or similarly qualified persons in order to avoid a hazard.
  3. Do not use it to charge primary batteries and use voltage not corresponding with cell voltage to charge the cell. For example, use 12V to charge the 6V cell, and so on.
  4. During charging, the secondary cell must be kept in places with excellent ventilation and protected from flame or spark.
  5. The charging current is generally selected as 1/10 of the secondary cell rated capacity, and the cell will be fully charged in 10-12 hours. For example, keeping the charging current for storage battery with 30Ah rated capacity at about 3A will be the best.  Too powerful charging current will shorted the service life of the cell.
  6. Due to the unsteady commercial electricity voltage, the hand of the ammeter will swing lightly in charging course and this is a normal phenomenon.
  7. When protection occurs, please check whether the charging current is too powerful or there is short circuit in the output clips. Eliminate the malfunction firstly and then go on charging.


Main Technical Parameters:




Input voltage

AC 200V-240V

Input frequency


Output voltage

DC 6/12V

Max output current