Test/review of Dlyfull M8 Battery Charger

Dlyfull M8 Battery Charger


This is 8 channel charger from Dlyfull that can charge most battery types.




The charger arrived in a brown cardboard box with a drawing of the charger and a list of supported batteries.

The box included the charger, a 12V power supply and a manual.

The charger is powered from the supplied 12V supply.

The power adapter is rated for 12V 3A.

The user interface contains 2 buttons and a LCD display.
When a LiIon battery is put into a slot a short press on the MODE button will select voltage.
Holding down MODE during operation allows selection of current, this make is a bit cumbersome to change current.
SLOT is used to select battery.
Holding down SLOT will restart slot with a new LiIon voltage selection.

All segments

Charging a LiIon battery in slot #2.

Charging a NiMH battery in slot #5.

The back has the usual specifications, but is rather hard to read.

The connection are the common slider style that can handle from 31mm to 77.8mm, this handles all normal sizes of LiIon and NiMH cells, protected or not.

There is also connectors for two 9V batteries. They do not use the display, but have a red/green led each. It shows red while charging and green at all other times.





Measurements charger
    Charging LiIon 4.2V
    Charging LiIon 4.35
    Charging LiIon 3.6V
    Charging NiMH
    Charging 9V

• When not powered it will discharge a LiIon battery with about 1.2mA
  
• When powered the charge will charge with about 1.0mA when finished.
  
• Between 0.0V and 1.5V the battery is assumed to be NiMH.
  
• Between 1.5V and 2.0V the charger will report Err
  
• Above 2.0V the battery is assumed to be LiIon.
  
• Charger will not restart if battery voltage drops.
  
• Voltmeter do not show correct below 0.9V
  
• Voltmeter is within 0.02V when in range.
  
• Slot #1 & #8 can charge with 0.2A, 0.5A, 0.8A, 1A & 2A for LiIon, but only up to 1A for NiMH
  
• Slot #2, #3, #4 & #5 can charge with 0.2A, 0.5A, 0.8A & 1A
  
• LiIon can charge two batteries at 2A, 6 batteries at 1A or 8 batteries at 0.8A
  
• NiMH can charge 8 batteries at 1A
  
• Background light will reduce brightness when no buttons are used, but display is still readable.
  
• Power consumption when idle is 0.32 watt (Power supply is 0.07 watt)
  

Charging LiIon 4.2V

The charger has a nice CC/CV charge curve and about 100mA termination current.
Display shows: 3119mAh

Display shows: 3096mAh

Display shows: 3066mAh

Display shows: 3110mAh

Display shows: 3095mAh

Display shows: 3078mAh

Display shows: 3212mAh

All slots look similar.
Display shows: 3191mAh

Display shows: 2626mAh

Display shows: 2853mAh

Other capacities looks fine.
Display shows: 2158mAh

The 14500 cell also looks fine.
Display shows: 1005mAh

Any cell can be charged with 0.2A, but it can take a long time.
Display shows: 3119mAh

No problem with my old and very worn down cell.
Display shows: 74mAh

Increasing the current to 1A works fine.
Display shows: 3168mAh

2A also works fine, the termination current is unchanged.
Display shows: 2976mAh

With 8 cells the maximum charge current is 0.8A
Display shows: 3010mAh, 2746mAh, 2938mAh, 3062mAh, 2948mAh, 3044mAh, 3041mAh, 3084mAh

And the charger can use up to 3A from 12V
Display shows: 2872mAh, 2879mAh, 3061mAh, 2620mAh, 2967mAh, 2963mAh, 3077mAh, 2974mAh

HS1: 52.2°C

M1: 35.9°C, M2: 36.5°C, M3: 38.3°C, M4: 38.4°C, M5: 36.8°C, M6: 36.6°C, M7: 34.9°C, M8: 31.9°C, M9: 41.2°C, HS1: 43.8°C

The charger needs about 10 seconds to turn on, partly because it waits for user input.

A full LiIon battery will be discharged with 1.3mA when the charger is without power.
Charging LiIon 4.35

Using 3.8V setting will charge to 4.35V
Display shows: 2971mAh
Charging LiIon 3.6V

The LiFePO4 setting charges to 3.65V
Display shows: 1225mAh
Charging NiMH

This NiMH charging looks like a voltage termination, there is a small trickle charge.
Display shows: 1880mAh

Display shows: 1992mAh

Display shows: 2158mAh

Display shows: 2127mAh

Display shows: 1930mAh

Display shows: 1949mAh

Display shows: 2046mAh

The other slots looks like -dv/dt termination
Display shows: 1975mAh

Display shows: 2649mAh

Display shows: 2556mAh

With the high capacity cells there are tow -dv/dt and one voltage termination and all batteries looks full.

The AAA cell is handles nicely on 0.5A
Display shows: 778mAh

The charger also terminated A AA NiMH with a 0.2A charge, but was a bit slow to do it.
Display shows: 2586mAh

Oops, for some reason the termination do not work this time around. Using 0.2A for a AAA cell is on the low side, there is no -dv/dt signal on the charge curve.
Display shows: 5696mAh

Termination on a full cell can be a bit slow.
Display shows: 259mAh

Using 1A works fine.
Display shows: 1894mAh

Charging 8 cells at 1A also works fine.
Display shows: 1825mAh, 1791mAh, 1841mAh, 1910mAh, 1821mAh, 1892mAh, 1854mAh, 1838mAh

It uses nearly 2A peak from the 12V supply.
Display shows: 1765mAh, 1763mAh, 1793mAh, 1811mAh, 1800mAh, 1835mAh, 1841mAh, 1839mAh

HS1: 65.6°C

M1: 34.7°C, M2: 38.2°C, M3: 39.1°C, M4: 38.0°C, M5: 37.8°C, M6: 36.8°C, M7: 34.0°C, M8: 30.7°C, HS1: 50.0°C

The charger is considerable faster to start with NiMH, it do not have to wait for user input.

The trickle charger is current pulses. On time is 2 seconds every 20.5 seconds with an average current of 60mA, i.e. the trickle charge current is about 6mA. This is a acceptable level.
Charging 9V


The current is about 30mA.

The 9V also uses pulsing current and can deliver nearly 11V, current is fairly constant at any voltage.
Testing with 2830 volt and 4242 volt between mains and low volt side, did not show any safety problems.
Conclusion
The charger works nicely charging the different battery types and has a wide selection of current available, but it is not really a super fast charger. Changing current is a bit on the slow side, especially with LiIon where you have to wait until the voltage selection times out and then hold down the button to enable current selection.
I will rate it as a good charger, even though it failed on a single NiMH cell.
Notes
The charger was supplied by a DlyFull for review.
Here is an explanation on how I did the above charge curves: How do I test a charger