Auto Scrubber/Sweepers Battery Charger Tips

We get calls every day about problems with cleaning equipment chargers. In many cases the person is looking for information on charger replacement is shocked to learn how much they cost. The chargers for auto scrubbers are designed for large amps and have large amounts of copper in them and you're paying for these things. 9 times out of 10, we can get them working for about $150, far less costly than a new one.

The number one issue is: It doesn't come on when I plug it in.

Check all fuses with an ohms meter, visual inspection is not good enough.

Okay, let's talk about what typically is going on. When you plug the unit into the battery pack, the voltage goes backwards up the connector and triggers a relay inside the charger to activate. If the charger doesn't get enough voltage backwards up the line, the relay will not trip and the charger doesn't come on. In a quiet room, unplug the charger from the wall, plug the unit into the machine and listen. You can hear the click typically. If the click doesn't happen, check the voltage at the machine's plug. It must be within about 3 volts less than the machines operating voltage. If not then the unit will have to be manually jumped to activate the charger, see below. If the click happens, then it is time to perform the jump test anyway to confirm the relay's functioning properly.

Jumping the charger:

Most chargers have a relay inside the cover. Before removing the cover, unplug the unit. If you are not qualified to do the following test, do not attempt to open the unit. By opening the charger you assume all risk of damage to the charger, the machine, yourself, etc. Typically the relay (click to see a typical relay) is a small black box about 1-2" square and has 4 wires connected to it. Two of the wires are for 120V, and the other two are for the voltage of the machine (12V, 24V, 36V, 48V) which are coming back from the cord going to the machine. To jump the charger into operation, remove the two 120V wires from the relay. They can be identified as 120V by using an ohms tester or following the wires from the wall plug to the relay. Place a jumper between them so they are directly connected. Plug the charger into the machine, and then into the 120V wall outlet. To not touch anything inside the charger, and make sure the charger is on a stable surface, you do not want it to fall. If the charger shows a charge and is humming now, then you need to replace the relay.

My charger is humming loudly after it was dropped?

That happens because the wires in the transformer have been broken loose and are now vibrating was the electricity goes through them. There is nothing you can do except replace the charger.

The charger was dropped and doesn't work?

Okay, start checking the things on this page, fuses, relays, and diode assemblies.

The charger seems to charge, but the battery pack doesn't show full anymore?
Or:
The charger is only putting out 1/2 the amps it is rated for on a low battery pack?
Or:
The charger shows a fault after a long charging cycle?

This is typically the result of 1/2 of the diode bridge assembly not working. Replace the diode assemblies. This is typically one of three designs, call for help.

I don't want to fix it. Can you fix it?

Yup, we fix them all the time and stock most of the parts. Call the office, get and RGA#, ship the charger in a REALLY tough box (and we mean really tough, extreme packaging required) by UPS. We will repair the unit if we can, and ship it back. We strongly suggest you call us first. We see many chargers get sent in, and they work fine when they arrive here.

Do you sell replacement chargers?

Yes, they are sometimes listed with the equipment as a part. Others you will need to call us on them.