One of the stranger issues that I’ve seen with a Milwaukee charger is when it starts flashing red and green without a battery even on it. It’s not exactly common, but still concerning.
So, if you’re one of the few unlucky people in this mess, hopefully, I can help you today! I’ll go through a few troubleshooting tips to try out for this problem to get your charger working right again.
Related: Milwaukee M12 Charger Not Working No Light: Solutions I Recommend
3 Tips To Fix Milwaukee Charger Flashing Red and Green Without A Battery
- “Reset” The Charger
Most of the time something like this happens, it’s just a technical bug with the Milwaukee charger. That’s something you can fix by “resetting” it instead of simply restarting it.
Unplug the charger from the power outlet to do this. Let the light on it stop flashing entirely after cutting power to the device. Keep it in this state for a few minutes, like I’m doing in the picture below.
Let some time pass, but don’t plug the charger back after that. While it still has no power, insert a battery inside. Make sure that it’s a healthy battery that your Milwaukee charger can charge.
Confirm that the battery is seated properly. If it is, you can now turn the charger back on. When you do this, it should recognize the healthy battery immediately after powering on.
The green and red lights flashing on your Milwaukee charger usually signal a bad/dead battery. However, they shouldn’t pop up if you’re using a healthy battery, should they?
In case you’re curious about the different meanings of the lights on the charger, I’ve also made a video on this topic. You can watch it below.
A solid red means it’s charging the battery and this turns into a solid green once the battery is fully charged. And as mentioned earlier, a flashing red and green means a bad battery while a flashing red only means a hot/cold relay.
When you turn the Milwaukee charger on with a good battery inside, that will take away any time for the green and red flashing lights to start, since the charger should sense the healthy battery.
For some unlucky users though, it might not end here. It can sometimes be a real problem instead of a simple bug. So, let me tell you what to do in case that’s what’s happening!
Related: How I Solved My Milwaukee M12 Battery Shows Green but Not Charging to Full Problem
- Internal Corrosion or Rusting
Your Milwaukee charger may have a fault with its connection points/sensors. If the last fix didn’t work for you, this is likely the case. This can happen because of corrosion/rusting.
A Milwaukee M12 charger with a problem on its sensors would cause it not to work properly including its lights. You can read this article I wrote about how to fix a Milwaukee charger which doesn’t work and also has no lights.
Problems such as these result in unreliable readings for the sensors inside the charger. Even without a battery on, it thinks that there’s one there regardless.
As such, the charger tries to send power to this battery that it thinks is there. But, the power doesn’t flow through, as there’s no battery really there at all.
Do you get where I’m going with this? Because of everything I mentioned so far, it thinks it is sensing a bad battery, and shows you the red and green flashing lights.
Most of the time, issues like this are found on the prongs on the charger. They’re the most exposed metallic component and can develop problems like this when you set the device aside for too long.
I want you to try and confirm if that’s the case or not by checking inside the device. Remove all covering, as I have in the image below, and check all the components for rusting or corrosion.
Noticing something like rusting is super easy. Milwaukee chargers aren’t exactly that big. If there’s any rusting or corrosion, you’ll see it clearly most of the time.
Once you confirm there’s rusting/corrosion, the next part is to clean it up. Now this is where things get hard. Because of the small size of its internal components, cleaning a Milwaukee charger isn’t easy.
Be careful so that you don’t move any components around and damage them. I suggest using a rust removal chemical and a cloth to carefully apply it all over the problematic parts.
- The Charger Isn’t Fit For Use Anymore
I mentioned earlier how the red and green lights flashing on your Milwaukee charger signal a bad battery. But, that’s not the case right now since there isn’t any battery there.
So, if the other two fixes I told you about didn’t work, maybe the charger you’re using is the bad one. Just like batteries, their chargers can die as time goes on too.
It’s bound to happen sooner or later. If you’ve been using this specific Milwaukee charger for a few years now, or bought a used one, that could explain why you’re facing this problem.
I think it’s definitely what’s going on if your charger is no longer powering any batteries and always just shows the red and green flashing lights. The answer is to purchase a new one in its place.
While this doesn’t “solve” your problem exactly, it still gets rid of it entirely. A new Milwaukee charger won’t have these complications and you can use it without worry since it’ll function for a long time!
