Bunker Hill Security 120 Lumen Solar Motion Security Light Review & DIY Modification


  • Brand: Bunker Hill Security
  • Model: 120 Lumen Solar Motion Security Light
  • LEDs: 20 SMD LED array
  • Battery: 3.2v, 600mAh Lithium Ion
  • Circuit board part number: DG606a
  • Bright Mode: 120 Lumens (motion detected)
  • Bright Mode Duration: 1 Minute +/-
  • Low Mode: 10 +/- Lumens (always-on after dark)
  • Low Mode Duration: From sunset till sun up (or till the battery is dead)

I picked up these 120 Lumen Solar Motion Security Lights from Harbor Fright on sale for $12.

  • Harbor Freight: In White, SKUs: 64732, 64733 $17.99
  • Harbor Freight: In Black, SKUs: 64736, 64735 $17.99
Bunker Hill Security > 120 Lumen Solar Motion Security Light


This light has two modes. The always-on Low-light mode seems to be around 10 +/- lumens. When motion is detected Bright-mode kicks in. 120 Lumens (about 13 watts) does not sound like much, but seems very bright in a dark back yard. Plenty bright to light up my back deck, and some of the surrounding area. Aiming the unit down at about 45 degrees from just above the door lights the door very well and out into the yard.

Motion Sensor:

The motion sensor on this unit works very well. I have the light mounted above the door, aiming down at about 45 degrees. The sensor picks up my motion as I approach, probably from 15-20 feet out.

Solar Charging:

Out of the box Solar Charging in this unit is not sufficient where I have it installed above my back door. The door faces West, and in Winter it only gets 4 hours of of sun light. That is not enough juice to run the always-on after dark low-light mode all night. The battery dies completely in just a few hours.

Always-On After Dark Mode:

This unit has an Always-On After Dark low-light feature. I think this low-light mode is around 10 +/- lumens. Always-On after dark is not mentioned on the packaging anywhere. I find the feature super annoying. I do not need or want the light to stay on all night. Even if it is just a dim light. This light would be perfect if it did not have this feature.

I went on a hunt to modify this light. My goal is to preserve the battery for what is important, to light up the door, the deck, and the stairs as family members come and go.

My DIY Modification

Why Disable the Always-On After Dark Mode?

I want to increase the battery life by permanently disable the Always-On After Dark mode. Without harming the Motion Activated mode.

With help from members of the All About Circuits forum, we’ve discovered a way to disable the Always-On After Dark mode by modifying the circuit board. Now the light stays off after dark, and the motion sensor still works perfectly.

How To Disable the Always-On After Dark Mode:

Look at the last two photos. Photo: Circuit Board DG606a layout illustrates the logical connection between Q2 and L+. This it the connection we will disconnect. Photo: Connection between Q2 and L+ is a close-up the joint. Un-soldered or cut this connection. I un-soldered mine.

Q2 is a surface-mount Transistor (M6). It has 2 leads on one side, and one lead on the other. Un-soldered or cut the lead, on the side with only one lead. Cutting the lead and insulating it from from the board may be easiest. But, I un-soldered mine.

Testing The DIY Modification

I’ve tested the DG606a circuit board modification in a real world setting for 20 days now. Motion tigers the light as it should. The sensor still detects motion 15-20 feet away. The light comes on in full bright mode (120 lumens). The low-light (6 lumens?) Always-On After Dark mode does not come on at all. The light stays off until someone approaches. Even with several back-to-back grey and rainy days the battery is maintaining enough charge to operate several times a night.

Published by


Kimball is a website designer and developer in Goffstown, NH.

6 comments on:
“Bunker Hill Security 120 Lumen Solar Motion Security Light Review & DIY Modification”

  1. I have the feeling that your schematic is wrong in a couple of spots, and it’s kind of… possibly doing more harm than good,

    The circuitry roughly matches the XY 8183 datasheet when using an external PMOS FET to primarily drive the LEDs.

    A1SHB is a P-channel enhancement MOSFET.

    Q2 appears to be a PNP transistor. It doesn’t make sense to have R2 connected to the emitter/B+. It makes more sense if that trace goes under the package and hits the base instead. So when Q1 pulls it to ground, Q2 gets turned on for “dim mode”.

    1. Thanks Alpesh. I removed the connection between Q2 and L+ as described above to disable the always on feature. That was a year ago and the motion sensor and light still works perfectly.

      I just bought another set but unfortunately the circuit board has been redesigned. The new SKU is 64736. I’ll write a new post when I figure out how to modify the new board.

      1. Just purchased a SKU# 64736 & was inquiring whether you had discovered the method to eliminating the continuous nighttime low light feature.
        The packaging does not mention that particular feature at all.

Leave a Reply

Your email address will not be published. Required fields are marked *