The opus BT-C3100 V2.2 is an intelligent 4 slot lithium-ion battery charger with a easily readable backlit LCD display. This charger supports up to 2Ax2 or 1Ax4 charging current. The BT-C3100 is a great choice for charging multiple 18650s at once and especially testing different cell’s capacitys with its numerous functions.
This charger can be found on amazon for $37.99
Specifications Listed by Manufacturer
The charger integrates the minus delta voltage for NiCd or NiMh battery charging termination, and for Li-ion batteries charging to 4.2V with pre-selected constant current. ( 3.7 Li-FeO4 and 4.35 type high voltage batteries charging mode can be selected through switch on board )
Easy to read LCD with back light Showing Battery Voltage, Charge / Discharge Current, Charging Time, Battery Capacity etc.
Operating temperature: 0 - 40 deg.C
Max charging capacity: Up to 20000mAh
Power adapter: DC 12V, 3.0A ( Output ), 100 - 240V, 50 / 60Hz ( Input )
- Voltage update rate is 30s instead of 60s.
- 4.35V charging time can be very long because charging current is regulated in entering the CV stage at 4.12V, which is same as 4.2V type. Now
3.35V charging algorithm is changed to 4.27V.
- New fan cover make better protection for cooling fan.
- Charging current range ( mA ): 200, 300, 500, 700, 1000, 1500, 2000
- Discharge current range ( mA ):200, 300, 500, 700, 1000 ( li-ion cell battery only )
- Max. charging capacity: 20000mAh
- Voltage deviation: max 0.03V 4.2V
- Current deviation: max 5%
Model: BT-C3100 V2.2
Rechargeable Battery Qty: 4
Input Voltage: AC 100~240V 50/60HZ
Output Voltage: DC 12V, 3.0A
LCD Screen: YES
Auto Circuit Detection: YES
Built-in Protected Circuit: YES
Over Voltage Protection: YES
Short-Circuit Protection: YES
Over-Charging Protection: YES
Over-Discharging Protection: YES
Battery Quantity: 4
Package weight: 0.558 kg
Product size (L x W x H): 14.4 x 9.8 x 3.9 cm / 5.66 x 3.85 x 1.53 inches
Package size (L x W x H): 16 x 22 x 5 cm / 6.29 x 8.65 x 1.97 inches
1 x Opus BT - C3100 Battery Charger
1 x US Power Adapter
1 x English User Manual
Included AC-DC adapter outputs 12v 3A Max
The Opus BT-C3100 is made out of ABS plastic and feels like is has a very sturdy structure and is built well. The buttons below the LCD feel very solid and have a nice click to them when used. The charging bays adjustable negative poll is attached via spring which also is very strong and holds the battery in place very well.
This charger holds 4 18650 cells comfortably and is very easy to extract them from the bays when they are done charging. Protected versions of all compatible cells fit snugly inside the charger except for protected 26650’s.
The negative end of the cell is just barely not connecting thus the problem with this charger and holding protected 26650’s
Cooling The unit
The charger has a cooling fan built in to cool down the internal components when charging at high currents
The fan is somewhat loud but not loud enough to be bothersome when in listening vicinity
The unit is approximately 4”x 5.75” or 10cm x 14.5cm
Display and Selectable Modes
The BT-C3100 has multiple different modes (Charge, Discharge, Test, Quick test, Refresh) and charging currents to choose from including 200,300,500,700,1000,1500,2000 mAH
Operating the Unit
Pressing the mode button will cycle you through the 5 selectable modes (Charge, Discharge, Test, Quick test, Refresh)
Pressing the display button will cycle you through the 4 different informational displays (Voltage, Current, Capacity, Charge time)
Pressing the current button will allow you to select the desired charging/discharging currents
Pressing the slot button will cycle through the 4 slots in the charger
The unit has 5 selectable modes including Charge, Discharge, Test, Quick test, and Refresh.
Charge Mode: The rechargeable battery is charged up to its maximum capacity. Accumulated charging capacity is displayed at mAH display mode.
The charger will charge 4 cells at once charging each at 1 amp. But if you are charging only 2 batteries you should put them in the outer slots (slots 1 and 4) to increase the charging rate to 2 amps a piece. This is especially good for charging 2 26650’s at the same time
Discharge Mode: Discharge mode is used to reduce memory effect, The rechargeable battery is discharged to a preset battery voltage (0.9v for Ni-Cd & Ni-Mh, 2.8v for Li-ion batteries). Once discharge is finished, total accumulated discharging capacity is displayed at mAH display mode.
Refresh Mode: The rechargeable battery is charged and discharged repeatedly to optimize to its maximum capacity. Old rechargeable batteries or rechargeable batteries that have not been used for a long period of time can be restored to their rated capacity
Test mode: Checks the present capacity of a rechargeable battery. The maximum capacity is determined by discharging the rechargeable battery after it was fully charged.
Quick Test mode: The charger will analyze the dynamic internal battery resistance by applying a load and the current reading is referred to the voltage drop detected on the battery. Within 10s, the tested battery resistance will be displayed in the unit of milliohm.
Supported Batteries/ Technical Data
This charger can only hold 2 26650’s in the outer slots
The Opus BT-C3100 V2.2 is a great all around charger option for all those who want to charge multiple cells at a time and for those who want to test the capacities of their cells. This charger can be used by anyone with any experience level due to the simplicity of the operation of the device. My favorite aspect of this charger is its ability to discharge your cells to get the exact readout of mA to see if your cells capacity is infact true to what the label says. The charger also fully charges all cells to a even voltage of 4.2 volts and trickle charges them to keep the cells topped off if you leave them on the charger after they are done charging.
The only thing I would have liked to see in this charger would be a higher charging current when charging 4 cells at a time, especially for high capacity 18650s it will take about 3.5 hours for them to fully charge at 1A
All in all I highly recommend this charger to anyone who wants a well built, multi mode charger that will act true to its specifications.