When you see your charger’s solid red light, there’s a problem. It means the voltage has become too low for the system to identify. And you’re not certain what happened. Your battery just quit functioning.
At first, you think maybe it’s a loose connection somewhere. But often times, the pack require help getting up and going. Here are three ways to revive it.
Revive With A Matching Battery
One is simply a second Fein 18V battery. Reach up on the shelf and pick out a good one. Be careful to identify positive and negative terminals. They is easily identified by molded symbols.
Attach the leads from both packs together. Positive to positive, negative to negative. Leave attached for about fifteen seconds. This will help to increase voltage enough.
Keep an eye on that connection here. Don’t let anything get warm. There is never any smoke around those contacts and the wires remain cold throughout the process.
What it does is share a little bit of charge. That’s what fools the charger into thinking there is some power still left. The result is your dead battery wakes up. Then it’s ready to be charged normally again.
Afterwards, remove the clips carefully. Inspect for any residue at the terminal area. All components should of being intact and clean. Set each battery aside temporarily.
If you’re lucky enough to have spares, this is a tried and tested solution. It is worth a try without having to resort to anything else. It is simple yet effective in practice.
You could also try a battery from a different brand. Try a DeWALT 20V pack as it is roughly the same voltage level most of the time. Hook it up based off the terminals. Again, positive hooks to positive; negative hooks to negative. Keep it connected for fifteen seconds. It just may shock you how well they work together across different brands.
It is the same deal as above. DeWALT gives up its juice as well. Fein battery takes the boost and becomes ready for normal charging once more. And we all know, it doesn’t care who made it.
What matters is the polarity and the voltage. This makes it a nice option if you don’t have a matching pack. This will end up saving you money in long haul.
The side has some info about labels. You’ll see the certification icons right away. That’s fine because they’re more or less for safety standards, so they don’t really impact the process. At this stage it’s just background data.
What you’re focused on is restoring power. The labels won’t get in the way and they do their job quite nicely.
If you look at the bottom of the DeWALT pack, it has vents to control heat while in use. You can see the connector pins clearly because they align perfectly with your setup. I found that connecting was easier then expected. Not only does it give you a little more flexibility here but there is a good chance others will connect like this. Remember that when looking later.
Finally, you need a DC power supply. This can be anything that puts out DC voltage but should have an exact output of 18 volts. Be sure to limit the amperage to only one ampere (this will cause the battery to recharge gently over time).
Again, connect your probes directly to the battery terminals. The positive probe goes on the positive side; the negative probe goes on the negative side. Leave it alone for fifteen seconds.
As you go through the process, numbers appear on the screen and they change. They hold steady at eighteen volts so we know that’s where the voltage sits. But the current keeps inching up as you go. That means that the battery is receiving power properly. It’s responding well to what you’re doing to it.
Because it’s in a controlled environment, there are no spikes whatsoever, only a safe manner of reviving your low-voltage batteries. Every time. No exceptions.
Be careful with your knob twiddling on the unit. This is not one of those things you do by feel or guesswork. You want to be precise here. Input the numbers, check them twice then hook it up. This avoids any risk of damage.
The power supply delivers steady voltage, but current readings increases slightly over time. Most of the time it duplicates a standard charge cycle, though it has some additional tweaky things you can do too. It’s a handy gadget for maintaining batteries.
All looks good; displayed readings say so. The voltage holds at eighteen all along and the current begins low and builds up slowly. Sounds just right, which is exactly what you’d expect.
Everything goes well from beginning to end. Nothing smells funny or sounds odd. Your Fein pack takes in the juice like a champ. You feel more confident after every right move.
Three methods to fix a red light on your charger
They come in contact with the probes snugly. If there is any loose contact, this will not work. So make sure there is always a solid electric connection between probe and contact.
Make sure grips are tight enough. A lot of people miss that one. It makes a big difference in how effective it is. Attention to details pays off. You take care with this and nothing goes wrong.
The numbers on the screen visibly change. Now it shows current numbers. It’s showing active charging now. This validates a fix for the low-voltage issue. The battery starts accepting current without any resistance.
Your charger knows there’s a pack. Soon enough you see green lights indicating that the unit has been brought back to life successfully. The problem is completely solved.
Red lead remains on the dock terminal.
The key here is that it never lets go, and keeps holding until it’s necessary to do so, allowing you to get maximum energy transfer. There are no interruptions at this stage. Patience rewards you for your efforts. And finally, the battery successfully returns to life. All is well; it’s good as new again.
But then the values change a little bit on the display screen. And that’s fully normal here. These slight changes indicates exactly what is happening in real time.
This means the system works fine. The Fein battery gets better and better over time. There are no unexpected error messages popping up. Everything goes smoothly according to plan. So you’re happy about the entire process.
When you’re testing, everything stays in order on your bench. All the tools are kept handy so that nothing will accidentally tumble or trip you up. Even with a casual atmosphere, safety is most important. Good habits always make for better results. This project shows that principle well. Make it a point to continue these standards.
Place the rejuvenated battery on the charger. Observe as the lights turn green. Green with a blink indicates it’s charging appropriately.
There’s something satisfying about seeing results from your work. It’s not just in your head. You’ve got a functioning pack now. You have one you can use. You won’t have to troubleshoot anymore. You did a good job.
Press that status button gently only once. The system knows there’s a battery in place and registers this information. Now the steady green LED illuminates, meaning the whole repair process is complete.
Your Fein tools can go back to work. These repairs will get you on your way and make you happy with the end results.
