[Solved] How To Calibrate XL4015 Module Current?

[johnyradio]

Hi,

i picked up one of these cheap charger modules, based on the XL4015 chip:

Current and voltage are set with the 2 trimmer pots.

How can i calibrate the output current? Can i connect my ammeter directly to the output? Or must i connect the meter in series with a load?

thx

 

[hiuintahs]

Re: How To Calibrate XL4015 Module Current?

Place a good digital volt meter (or your ammeter) in series between this charging board and your battery that you're going to charge. Make sure that the meter is connected to its current measurement terminals. Use the 10A range if it has one. Use a battery that needs recharging so that you know that you are in constant current (CC) mode. Use the current trimmer pot to set the current to the value you want.

Having a meter in series with a charging circuit can affect the termination voltage level (ie: cause the termination to be at 4.15v instead of 4.20v) due to the added resistance of extra wires, meter, connections points giving an addition voltage drop.............but it won't affect the current.

 

[johnyradio]

Re: How To Calibrate XL4015 Module Current?

Awesome answer, @hiuintahs!

More info to help others:

In constant-current mode, the boost will deliver a constant-current, no matter the load (hence the name).


The current pot sets the current only for constant-current mode. Once the charger switches to constant-voltage mode, the output current drops to a lower, slower charging-current. You have no control over the current during constant-voltage mode, which is why you must adjust the current pot when in constant-current mode.


solved!