There is a resistor that sets the current limit to 1.0 amp the way it comes. It is possible to change that resistor value to reduce the charge current. The thing is, I have never changed a SMD resistor. How do I heat it to remove it? Also, since the resistor ohms is increased to lower the charge current would it be as easy, or easier to stack another? At least it seems that should work. Any thoughts from any experienced hands would be appreciated. (The last resistor I soldered had wires coming out the ends of a tube that is huge compared to these SMD’s…. I date myself…. ) Good thing I have magnifiers.
Hotplate / stove top reflow makes it much easier. Get a spare food thermometer to keep an eye on the temp. Also do you have solder paste? Makes smd easier. Fasttech carries an inexpensive jar of solder paste.
Stacking resistors lowers the ohm value.
You don’t have to remove the resistor. Its value is 1.2k (first link) so if you want about 500mA charge current, solder a 1.2K ohm (1/4W) resistor across the SMD resistor and you’ll be fine.
If you want to remove the resistor with a soldering iron put a drop of flux on the resistor and some solder on the tip and set the tip alongside the SMD resistor so the solder touches both ends. The blob will allow both ends to melt and then just wipe the tip sideways to remove. To replace with another value hold the part in place with tweezers and solder first one end and then the other. Again use flux.
I did some research; resistors in parallel (stacked) increases the wattage and reduces the ohms. Two of the same value means the ohms would be halved. So it appears I would have to change the resistor if I want to increase the resistance tolower the amperage of the charge current.
Yes. Thats how I understood the mod to go; increase the resistance to lower the output. For really small cells like 10180-10280 it’s a really good idea.
I remove and replace the SMD resistors just as Rufusbduck describes using a 25 watt pencil tip iron. Fortunately these resistors are quite tolerant of heat and hard to damage even if you take too long with the iron.
) Good thing I have magnifiers.