Quick Guide: Replacing Your Floor Scrubber Batteries with VMAX MR137-120

Is your floor scrubber struggling to hold a charge? It’s time to swap out those tired batteries for the heavy-duty power of the VMAX MR137-120.

This guide will show you exactly how to safely remove your old batteries and install your new ones. Because your floor scrubber requires two 12V batteries to create a 24-volt system, the wiring instructions below are critical for proper performance.

⚠️ Safety First

Before you start, please ensure you have the following:

• Safety glasses and gloves.

• A wrench or socket set (usually 1/2" or 13mm).

• Important: Remove any metal jewelry (rings, watches, bracelets) to prevent accidental short circuits.

• Ensure the floor scrubber is turned OFF and disconnected from any wall chargers.

Step 1: Remove the Old Batteries

Take a picture of the current battery setup with your phone before you touch anything. This serves as a great reference!

1. Disconnect the Main Negative: Locate the black cable that runs from the battery directly to the machine. Disconnect this first.

2. Disconnect the Main Positive: Locate the red cable that runs from the battery directly to the machine. Disconnect this second.

3. Remove the Jumper: Remove the short cable connecting the two batteries together.

4. Lift Out: Carefully remove the old batteries. Note: Group 31 batteries are heavy! Lift with your legs, not your back.

Step 2: Position the New VMAX Batteries

Place your two new VMAX MR137-120 batteries into the tray. Orient them so the terminals (the metal posts) are easy to reach.

Pro Tip: Most floor scrubbers position the batteries side-by-side. Ideally, place them so the Positive (+) of one battery is close to the Negative (-) of the other.

Step 3: Wiring Your Batteries in Series (24-Volt System)

To power your floor scrubber, we need to combine the voltage of two 12V batteries to make 24 Volts. We do this using a Series Connection.

Follow these connections in order:

1. Create the Bridge: Take your jumper cable (the short cable). Connect one end to the Positive (+) terminal of Battery A, and the other end to the Negative (-) terminal of Battery B.

   • Result: The batteries are now linked.

2. Connect Main Positive: Take the machine’s Red (Positive) cable and connect it to the remaining empty Positive (+) terminal on Battery B.

3. Connect Main Negative: Take the machine’s Black (Negative) cable and connect it to the remaining empty Negative (-) terminal on Battery A.

The Golden Rule: You should have one cable connecting the two batteries to each other, and two cables (one Positive, one Negative) going out to the machine.

Step 4: Tighten and Test

1. Secure Terminals: Ensure all bolts and nuts are tightened securely. Loose connections cause heat and reduce run-time.

2. Turn It On: Turn on your floor scrubber. The battery indicator should show a full charge.

3. Charge Up: We recommend giving your new VMAX batteries a full charge cycle before their first heavy shift to ensure maximum capacity.

Need extra help? If your machine setup looks different or you have questions about cables, our VMAX support team is here to help you get back to work. Contact us