snap on ctc772 charger not charging

Snap On CTC772 Charger Not Charging – Why Does It Happen & How To Fix It


You have a lithium-ion battery charger. You wanted to charge your devices with it but it doesn’t work. But we know what to do.

The problem at hand is snap on ctc772 charger not charging

The problem could be both from the battery or charger. The charger could be internally damaged. For the battery, lower voltage & unfavorable temperature can be the cause too. Power source voltage fluctuation can cause temporary problems in charging too.

Now that we know the basics, let’s jump into the details. We have prepared an article for you explaining it in detail.

Let’s get started!

What Are The Reasons Behind The Problem?

The snap on ctc772 is a lithium battery charger. We use lithium batteries on most power-hungry electrical devices that require a battery. For example, we have dewalt dcl040 light which uses a lithium-ion battery.

This charger can charge 14.4 volts of lithium-ion batteries which are quite standard. 

But just like everything, problems occur in these devices also. The most basic and noticeable problem that happens is the battery doesn’t charge anymore.

There are a lot of factors that can cause this problem to occur. Which includes both the battery and the charger.

Here we will discuss some of the common causes that can be the reason behind the problem. And later you will get to know some of the fixes that you can try.

A few common causes are 

1. Internal Wire Damage of Charger

The charger powers the lithium battery using ac current. And the internal circuit is designed to deliver the current to the battery,

If there is any kind of damage to the circuit the charger won’t work. There could be a loose wire that caused an open circuit fault. Or two exposed wires got connected, which would cause a short circuit fault.

2. Input Voltage Variation 

As you read earlier, the charger supplies AC current to the lithium-ion battery to charge. And the charger is plugged into the main wall socket. From which it draws power.

The voltage we get from the wall is uniform all over the country. And the electronics manufactured are designed to handle that kind of voltage. 

But sometimes the power delivered from the main station could vary in voltage.

If it is high voltage then the charger will likely shut itself off for safety. That’s why electrical outlets are connected in parallel. Or they might draw a huge amount of current. But low demand connection like the wiring of garage lights is done in series.

Low voltage will simply just not deliver enough power to charge your battery. 

3. Temperature of Battery

This is an interesting scenario that many don’t know about. There is a certain threshold of temperature that a battery should before it can charge or discharge.

If your battery is colder or hotter than the threshold temperature then the battery won’t charge due to safety reasons.

This happens usually on colder days when the overall room temperature falls down or it can happen due to some overheating issue with your battery.

4. Low Voltage of Battery

This is a problem that is commonly found in lithium-ion batteries,

All lithium-ion batteries have a lower limit of voltage in them. If the battery’s pre-existing voltage is lower than that voltage boundary, it will not charge. 

Battery manufacturers ship the batteries with 30-40 percent of charge. But if the batteries are unused for long then the battery voltage can drop below that limit.

Now that we’ve seen the possible reasons behind the charging problem, let us explore some solutions as well.

Solutions That Are Worth Trying 

We have seen various causes of the problem. From both battery and the charger. 

Let’s see if we have some solutions to those as well. 

Firstly, if the problem is internal from the charger, then there is very little that you can do. 

Opening and tinkering might damage it even more.

To prevent it you can use noalox anti-oxidant your conductor wires. This prevents oxidization and keeps exposed wires safe.

If the weather is extremely cold, there is a chance that it could be a temperature problem. In that case, try to warm up your battery. 

You can do that using a  warm cloth or plug it into an outlet that is near your kitchen. 

If you see that the battery is hotter than it should be, you should not try to charge that. Rather you should discard that battery.

Lithium-ion batteries can explode, and they explode if exposed to heat. Maintain caution while handling it.

You don’t have many ways to understand if the battery voltage is low. If you can measure it and see that’s the case then you can charge it up a bit. 

What you can do is, you can plus the 2 ends of your battery to a variable DC source battery and give your battery some voltage.

Here are some of our favorite variable DC source batteries:

We hope this helps you make a well-educated choice while getting a variable DC source battery.

Now give just enough to charge up your battery above its lower limit. That should get the battery to work.

That’s it for this article. Hope now you understand what to do when your Snap on Charger isn’t charging.


Question: Does overcharging cause any problem?

Answer: Yes, overcharging your battery frequently will damage your battery. 2-3 times might not affect it but if you keep overcharging for a long time the battery can swell up and get damaged.

Question: Can I charge my lithium battery with anything else?

Answer:  Yes, lead-acid battery chargers also work on lithium-ion batteries. But you have to maintain some caution while doing so.

Question: Is lithium batteries toxic?

Answer: Yes, it contains various toxic chemicals. You should never break open the battery and expose the chemical inside. And it can’t be disposed of in water bodies.


We hope you got everything you needed to know about snap on ct772 charger not charging.

Now you can take the necessary steps to check what’s the main cause. Hopefully, you’ll be able to fix it as well.

Have a great day!

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