I purchased an e-bike which was advertised as just needing the batteries replaced. The li-ion batteries had been sitting dead for months. Once I got the battery removed it was clear that was not the case. You can see the hole where the plastic melted from this component overheating on the board. The burnt one is the same as those in the center of this photo.
What is it and how do I determine the correct replacement?
looks like a surface mount chip resistor, 22 ohm?
As Altima said, it’s a 22ohm SMD resistor. You’ll need to measure it to get the package size.
Unfortunately resistors don’t really just burn out. If the resistor did cause damage from overheating, it’s because something drew too much current. My guess is there’s a short somewhere else, but there’s almost certainly more damage than that resistor.
Good luck!
I was thinking the same. How the heck does a resistor cause that much damage? Definitely not the resistors fault alone.
This right here. It’s likely not the resistor itself even though it’s showing the most symptoms of the overall problem.
Somewhere along that circuit branch is a short or something causing too much current to be drawn through the resistor here.
I dont think the resistors are faulty but the design. Resistors (especially low-ish value 22Ohm ones) are meant to dissipate energy as heat. Putting them in a cramped housing made of plastic, then using them to dissipate high power is going to build up heat in there. There could also be another component faulty that puts too much current into the resistors. They are probably part of the balancing circuit.
This is my first post here. Have I attached the photo correctly?
I can see the photo. Can’t offer help though.
They are 22ohm resistors. You can see they are resistor by the marking R on the pcb. The first two digit is the value (22), the last is the multiplier (0), so it would be 22*10^0 =22 ohm
Looks like a 22 ohm resistor
Clearly R27 is installed backwards 😹 oh yeah also you can guess that they’re resistors because the label (screen print) uses an R to identify them
As a resistor, there isn’t a forward or backwards. Diodes and some capacitors perhaps, but resistors have no forward or reverse bias. Upside down might be a problem because all the electrons will fall out. /s
Maybe I’m looking at the wrong thing, but I don’t see melted plastic. I see a collapsed bubble (a “fisheye”) in the conformal coating that is providing moisture resistance to the components.
You can replace it with any resistor with the same resistance and power rating. It may be easier to solder a larger through hole resistor onto the pads. I think other posters have figured it out, but you can search for resistor code information to decode it yourself. You can buy resistors lots of places, RadioShack was the go to place but I think hardware stores sometimes have them. If you’re not in a rush I recommend ordering a kit with a few different kinds.
