Karcher Window Vac Not Charging? (this is why)

The karcher window vac is a great household tool. Not only does it clean windows and leave them streak free, but it can be used on mirrors too. It works well in the shower too, drying the surfaces to help prevent limescale. 

If your Karcher window vac stops charging, you’re going to be in a bind. You’re going to want to know what’s wrong with it and how to fix it. Which is where this article comes in, keep reading to find out the answer to both of those questions.

Why Is My Karcher Window Vac Not Charging?

We always find it pays to get an understanding of how a tool, in this case the window vac, actually works and charges as we can then work out exactly what’s causing the problem. With the Karcher window vac, if it’s not charging the problem is likely to be one of two things, either;

  1. The battery
  2. The charger

Karcher Window Vac Battery

Depending on the model, you’ll either have a removable battery or a battery that cannot be accessed at all. Whichever model you have, the battery will be lithium-ion. These have proved to be safe especially during charging, and hold a charge for up to 30 minutes. 

They also tend to last for quite a long time, in many cases 2 to 3 years or 300 power cycles (charges). They then tend to need replacing, it is possible to keep on using them but you run the risk of them starting to leak or even exploding in some rare cases. You’ll know if your battery is getting past its best because it’ll lose its charge faster. 

When you first purchased the window vac it would run for around 30 minutes, but as the battery gets older, you’ll find the run time on a full charge decreasing to 20 then 10 minutes.

Karcher Window Vac Charger

As with all electrical appliances, your charger will have an expected lifespan and it is possible to buy a replacement charger. However the charger will usually last far longer than the battery. The expected lifespan of the window vac charger is around 5 years, so, twice the expected lifespan of the battery.

If your Karcher window vac isn’t charging, it’s more than likely to be the battery causing the problem and not the charger.

Can My Karcher Window Vac Be Fixed?

Plug socket in UK

Just like anything electrical, it is possible to fix or in this case replace the battery. However, replacing the battery could invalidate any warranty you have on the window vac. Which means even if you successfully replace the battery without causing any damage to the appliance any further faults will not be covered by the warranty because you’ve tampered with it.

You might find someone who repairs this type of appliance but the costs involved with parts and labour would make buying a new window vac a better option. 

Sadly yours isn’t an isolated case, many users have experienced the same issue. In many cases it’s just the fact that rechargeable batteries have a certain lifespan and that has reached its end. However, there have also been a number of cases where the window vac is less than 2 years old. But on investigation the window vac was left plugged in constantly which does damage the battery and shorten its lifespan.

Removable Batteries

If your window vac has removable batteries you can buy replacement batteries from a wide range of distributors and replace them without invalidating your warranty. Don’t try this on models with batteries that are not supposed to be removable as you will need to dismantle the appliance and the battery is likely to be soldered in place.


If your window vac is still under warranty and you haven’t tampered with it in any way, there’s a good chance that you can get it repaired by the manufacturer or one of their agents. This could entail sending it back to Karcher directly or taking it to the store you bought it from.

Other Reasons The Karcher Window Vac Isn’t Charging

There could be several reasons which led to the window vac not charging, in many cases it’s often human error. Any one of the following could cause your Karcher window vac to stop charging;

  • Battery Completely Run Down
    Unlike many other rechargeable batteries, the Karcher window vac’s battery should never be allowed to fully run out of power before recharging.
  • Over Charging
    Once it’s fully charged it should be removed from the charger. Unplug the window vac once it is fully charged. Incidentally, over charging is bad for all rechargeable batteries, not just those in the window vac.
  • Damage
    If you have dropped the window vac or accidentally hit a wall etc, this could damage the battery. Always take care when using your window vac.
  • Water Penetration
    Water and electrics don’t go together, if water has penetrated the outer casing, it could cause just enough damage to prevent the battery from charging.

If you do suspect any of the above to be the case, contact Karcher and explain what’s happening and see if your window vac is still under warranty. They’ll advise you on your next steps.

Frequently Asked Questions

How do I know my Karcher Window Vac is charging?

If the light on your Karcher window vac is flashing, you’ll know that it is charging. It will continually flash until it is fully charged when the light will stay on permanently. It can take up to 2 hours to fully charge.

Can you replace the battery for the Karcher Window Vac?

There are some models which can have the batteries replaced, specifically the Karcher WV5 and WVP10. These can easily be replaced and will hold a charge for 35 minutes.

What type of battery is in a Karcher Window Vac?

The type of battery used in the Karcher window vac is a Lithium-Ion battery with a typical capacity of 2600mAh.

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