How to reset Ryoby OP40401 40V 4AH Battery Pack

Written By: Emme

Comments: 2

How to reset Ryoby OP40401 40V 4AH Battery Pack

Difficulty

Easy

Steps

Time Required

10 minutes

Introduction

When the battery pack does not charge and the charger blinks red and green, resetting the battery may solve t problem.

Tools

Step 1

To open the battery pack you need to remove the 4 screws on the bottom of the unit.

Step 2

Flip the battery pack and remove the cap covering one of the for screw.
Use a pointed object (such as the iFixit P2 screwdriver) to remove the cap by sticking it in the middle of the cap and lifting out. Trying to grab the edge of the cap is much more difficult.

Step 3

Remove the 4 screws using a TR10 Torx Security Screwdriver.

Step 4

Using a utility knife, peel off the top half of the label covering the charge indicator lights (or you can cut the label in half).

Step 5

Be careful to not touch the board or the terminals.
Note the board part number: 280487 revision Q.

Step 6

Use a piece of insulated wire with the ends stripped to create a short between the two terminals indicated in the picture.
You may get shocked if you touch any other part of the battery pack while inserting the two wire ends into the terminals.
After a few seconds the 4 lights will turn on: the battery pack is now reset.

I assumed that the reset is a pretty safe procedure. But It looks not, at least for some failure.

Instead fixing, my reset burns the bridge next to the terminals. Some checking is necessary before reset.

My board is 280487 revision v1.3, the layout is almost like this one.

I checked a few things before reset.

The led lights, when press, light all four very shortly, then the led 4 flash 4 times. this similar to a working battery with low power. It's different from a common failure battery flash all 4 leds 4 times.

The voltage between T+ to T- is 0V, that's why it not working. The GND and BATT+ is 38.4 V, GND to T+ and T- is also 38.4 V,

The voltage between reset is 3.3v.

After the reset the two side of the bridge is 38.4 V.

Here's the link for the PBC with burned bridge.

PXL-20230916-132536732 hosted at ImgBB — ImgBB (ibb.co)

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