I have been using my Battery Tender Charger for quite sometime now and it has always been a reliable and portable little charger to handle all my lithium batteries. Recently, I plugged the battery in as usual but nothing happened, no charging and no light, indicating an issue.
At first, I thought it was a charger issue but after some trial and error, I figured out some common reasons why it happens.
But before you continue reading this article, you may first watch the short video I made about this topic. You can watch it down below.
On the video I showed the 4 reasons why your Battery Charger won’t charge and what you can do in each situation to fix the issue.
4 Reasons Why Battery Tender Not Charging
Here are a few common errors that occur with Battery Tender, read along to make troubleshooting easier:
Case 1: No Light Flashing
A couple of days ago, I plugged in my lithium battery as usual but the charger showed no light and no charge. The first thing I thought of is that maybe it’s a connection issue, but the plug was not damaged and the power was on.
Next, I decided to check on the charger fuse, for that, I opened the black fuse casing by gently pulling it open. Then, I turned on my multimeter to test the continuity of the connection and it turns out it was an internal short circuit that damaged the fuse.
I replaced the dead fuse with a fresh one and just as I expected, the battery started charging again.
Case 2: Flashing Red and Green
Usually when this error happens, it’s mostly me plugging the battery clips in the reverse polarity, but this one time, the indicator kept displaying red and green lights even with the correct polarities.
I inspected the battery again to find out that the battery was swollen and couldn’t charge anymore. Sometimes, an inner short circuit also makes the Battery Tender flash red and green lights, that might be an indicator for checking for damage and discarding the battery if necessary.
I also made a short video about this topic which I uploaded on YouTube but you can also watch it below.
Case 3: Flashing Red
Once, while charging my 12V lithium battery, the Battery Tender kept flashing a red light so I let it charge for a while but the flashing light did not stop blinking.
So I decided to check the battery with a tester to see if it is dead, the tester did not show any power so next I checked the voltage of the battery.
The voltage of the battery had drained below 3V, which meant the battery wasn’t dead, it just needed a jump start. To do that, I took a charged battery with a voltage of 11V and connected the terminals of both the batteries with jump wire clips.
I let the two batteries share charge for a few minutes before checking the “dead” battery again and the voltage now was around 5V, ready to be charged again.
I also have a short video about this topic in which I showed how I reset the faulty battery and you can watch it below.
Case 4: Solid Red light not Turning Green
A normal battery changes from red to green after a few minutes but one time, I let this old battery charge for about an hour and it still did not show a green light.
Turns out, it was a faulty battery that cannot carry a charge and would keep draining. Old batteries do that sometimes, they stop charging altogether and there’s nothing you can do to fix them and the red light not switching to green is an indicator that the battery is now too old to charge anymore.
And before I end this article, I also would like to share to you the short video I made about this topic. You can watch it below.
