1st 445nm build and i have problem with voltage needs

[deadshadow]

i have a 445nm diode its the A model not the M i guess(seller claimed to be 1,6w but i dont believe that) and this driver 1 8A Universal Laser Driver for 445nm 638nm 520nm 808nm Diode DIY Laser Pointer | eBay

i pressed into a module and the module on a heatsink,so this driver is supposed to work with 2 lithium batteries and output up to 1,8A,so i put 2 18650 and it was only letting me go up to around 800ma:wtf:.i was cunfused and i guessed ok that needs some more volts so i put another battery and a small heatsink on the driver also,it works but this time is limiting me up to 1,2A.what am i missing here?is the driver faulty?i wanted to use 1,4-1,5A but i cant keep putting more batteries on this thing lol.any help apriciated thanks

 

[Chrisbee]

What brand batteries are you using?
If the batteries aren't up to par, it could cause similar issues.

 

[deadshadow]

batteries are ok,i have some used sony on good condition and some new sanyo,the driver can be fried if i use 4 batteries right?

 

[Pman]

That driver says it is good to 9V so you should not be using anything more than 2 batteries. Taking a big chance on frying the diode, driver or both.

 

[deadshadow]

you are right but how can i increase the current then?with 2 batteries i can only go up to 800ma,btw i tried with a 12v battery those 1,3A,i messured it and it was almost empty(i was reading 12,1v without load)and the results in output current was higher(the 3 lithiums have around 12,5v with no load).maybe the volt of the batteries just drop when the diode draws 1+A out of them?

edit:just messured the current under the diodes load and the volts droping to 10,3 and the output voltage(the voltage on the diode)is 5,53

 

[Cyparagon]

How are you measuring the current? Also, what is the voltage across the current sense - the part that reads "1R0"?

 

[deadshadow]

i measuring the current with the multimeter in series in one of the 2 cables that goes from the driver to the batteries or the same for the diode(im just messuring hom much current passing through the diode or driver).the voltage on the 1R0 is 0,73,i from what i can see the driver has 2 1R0 and i only messured the one near the pontetiometer,do i have to mesure the other one also?

 

[Hibro]

The pot on the driver are for adjusting the current. Have you try that? I have one driver look exactly the same will go 1.8A with no problem

 

[deadshadow]

yea thats what my problem is,the pot locks on certain ma per cell no matter how much ill turn it

 

[Cyparagon]

Both of the 1ohm resistors (1R0) are in parallel. A voltage of 0.73V means the current through them is 1.46 amps. I suspect you are measuring current wrong, since the internal measurement of the driver looks fine as you've outlined it so far. Maybe your leads are chinese garbage that drop too much voltage to measure current properly.

I would trust the voltage across a current sense before I would trust some random ammeter setup.

 

[deadshadow]

that could be the problem,you mean the leads that goes from the batteries to the driver or the leads from the driver to diode?btw i tried a 12v 1,3A battery and its working fine,also i set the curent to 1,4A but still that thing isnt very portable so i still need to use smaller battery


EDIT:thanks for the help problem solved and it was the bad leads from the batteries to the driver,now its working great with 2 18650