Bunkerhill Security Light Modification

Thread Starter


Joined Feb 18, 2013
Hi all,

I have a motion sensor security light that I purchased from Harbor Freight: http://www.harborfreight.com/36-led-solar-security-light-69644.html

The unit works fine, however it stays on when the sun goes down when the solar panel no longer receives light. It does have a motion sensor to detect that someone is moving, thus triggering the LEDs to become brighter. I do not want this to happen, I only need the light to come on if motion is detected.

My solution to this is to use a forward biased diode to only let voltage through that is in the higher setting, however I am not sure what part (or component) I should be using.

I have tested the two states and their voltage outputs are as follow:
low light: 2.57
high light: 2.69

Thanks for any help.


Joined Nov 30, 2010
This is a variable current drive, not a variable voltage drive. If you install a part that interferes with the voltage, the machine will compensate and render it useless. I need a schematic to figure how to influence the operation correctly. Can you do that?

Thread Starter


Joined Feb 18, 2013
I am not sure if there is a circuit diagram available, I could not find one on the internet. I can take a picture of the board, which is labeled TG-010 PCB V1.

If it is current drive, I am not sure how to precede.


Joined Nov 30, 2010
Photo both sides. Try to read part numbers if there are IC's on the board.
If there is a way to cancel the low drive function we have to try to trace out the circuit.


Joined Mar 4, 2011
well I only see the one controller and would be willing to bet that we are getting control off these pins one would be low and one high if you desoldered the low side it should still think it is workin right yet get you what you want.
I have a set of these also will digmine out and see about modding it too.

Thread Starter


Joined Feb 18, 2013
madman6233, if you could provide a description of the location of the controller chip, I could test the voltages coming out of it to try to determine the low control.



Joined Apr 6, 2013
I have attached pictures of the board. It is quite complex, with lots of resistors and IC chips. I quickly googled some of the numbers and they are mostly battery voltage regulators.

Thanks for the help.
Did you find a way to modify? I may be wrong but I think this does not detect light but turns on dimmer light when there is a low or no output from array.
I wish to do the same as you.

Herb win

Joined Jan 1, 2014
I just purchase the bunker hill security 36 led light and having review the chip biss0001 That was mention in you fourm and can't find the right pin to disable the light from coming all the time. Could you please review this again.


Joined Mar 26, 2014
O have the same problem.
I fixed removing R22.
The light is comming out only when somebody is in front of the. Light

Have a nice one


Joined Feb 3, 2014
The chip only is used for the motion detector part of the circuit. The solar panel enables the low light setting while the chip only increases the light. Remove R22 at your own risk.

At 6 lumen, I'd keep the low light on if it stays on most of the night. What kind of lithium battery does it have? LED's don't wast a lot of power and burglars prefer dark places.
Hi all, I had to create a new account here because this is the exact question I've been having! So, a bump to this old thread.

After looking at the board, it would seem that there should be some way to achieve only the high light setting.

Burger2227, to answer your battery question: It uses a single 14500 3.2L LiFePO4 battery that is actually replaceable!

Here's another schematic of the possible controller chip if anyone can see which legs may be smart to cut/try?

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Well, as a follow-up I removed R22 as a poster above suggested. It actually works and only has the "high" power light when motion is detected. I wonder if the charge circuit has been changed though. Only a bit of time or more in depth circuit knowledge will tell.
The Harbor freight 36 LED security light that I bought 10/1/14 now uses a different control board. I was annoyed by the always on function, it cycles the battery way more than necessary and shortens its life. I'm putting the light up at a seldom used summer cabin, and I don't want a constant glow attracting curious people to it while I'm not there.

The new board uses a power transistor to ground the LED's, which are connected to Batt+ all the time. 3 circuits are attached to the driver (base) side of the transistor. The first is the output of the motion detector IC through a diode and a resistor, which controls the full bright current. The second is a resistor bridging straight from B+, this sets the constant low light current. And the third is a smaller transistor that shorts the control circuit to ground, this is powered by the input voltage from the solar panel and is what turns the LED's off when the sun is out.

So the circuit to go after is the resistor bridging straight from B+ to the LED power transistors base terminal. It's labeled R8 on the backside of the new style board. Nip it out of the circuit and it now works as a motion only light.
I had the same desire to have the 69644 LED's turn on and off (no low level LED power) with motion so thanks the mod worked as prescribed! The battery should now have plenty of reserve capacity how do I go about installing some more powerful LED's?


Joined Mar 1, 2015
Just an FYI, the unit I got on 2/28/15 is now sealed. There are no screws on the back any more. I haven't tried, but I suspect opening the unit will be destructive.