500 Led Extreme flashlight (from 2008)

Here are the specs of the 500 led extreme flashlight.

Build specifications

  • 513x 22.000 mcd 5mm led’s (series of three)
  • 7Ah 12v lead acid battery

characteristics (at full power)

  • 3500 – 4000 lumen
  • 10 min battery power
  • 53 Watt power consumption (including 3 Watt resistor power consumption)

Controls explained

I get allot of comments “the controls are over complicated”. And nobody knows exactly what the controls are for. In this page I will explain all the controls in detail.

Some points that had to be taken into the design.

  • Different brightness settings, achieved by powering different amounts of led’s.
  • A voltage safety switch to prevent a to much discharged lead acid battery.
  • Easy to charge battery without extracting the battery.


On / off switch and safety system

First switch to use is the “system” / “charger” switch. Here you choose if you want to battery connected to a charger or to use the battery for the flashlight system. On charger mode, the flashlight is completely disconnected to the flashlight by a 6 pin switch. On this mode you can plug in a lead acid battery charger. The simple charger I use has a led on it that turns orange when charging, and turn green when it’s finished. When you want to use the flashlight you can turn the “system / charger” switch to system. At this time, the flashlight is not powered yet. You need to switch the “on / off” switch. Note that there are some led control lights on the control panel. The first green led lights up when there is power on the flashlight system. So the “system / charger” is set to system, and the “on / off” switch is set to on.

At this point you can’t use the led’s yet. I wanted a voltage safety to prevent to much discharged of the lead acid battery. So for this I created a voltage auto switch circuit. That’s the second control led called “safety ok”. When the green led lights up, the voltage is “ok” and above the minimum.. For the voltage safety system I created three buttons. Two push buttons which can activate the safety (green pushbutton), and stop the safety (black pushbutton below it). When the safety is “ok”, the front led’s will turn off when the voltage drops below a certain point. When that happens, the green “safety ok” led turns off, and the safety system stops. When you try to start the safety again it will shut down as soon as you released the safety system activate button (green pushbutton). But when holding this button you will see a fifth red led blinking called “low voltage”.

The third safety system button is called “override”. This is a switch that can be turn on or off. When on the power is by-passed by the safety system. And the flashlight can be used, even at low voltages, but you need to know what you are doing, and prevent a to much discharged battery. When the override is active, both “safety ok” and “low voltage” led’s are still working. So you still can see how the voltage of the battery is doing. The override can be handy when your battery is not fully charged but still has enough juice left in it. Because, when you use all the led’s (phase 3), because of the drain on the battery the voltage drops around 1 volt. So the safety may be ok in standby, but when used, the safety stops. As long as the safety is ok on standby, the battery is fine. And when override is active, you can see the safety automatically turns on and off without power loss to the leds. So when you use allot of full power, check reguarly if the safety still activate when turning of the leds for a second or two. But when the system don’t get active even when all leds are off, the battery is to low on juice to use safely without damaging the battery. When using the flashlight for a long time on phase 1 (3 leds) or 2 (100 leds), it’s recommended not to use the override. Because you can easily forget to turn the flashlight off in time.

When there is power on the led switches itself, the thirde led will be on “led system on”. At the image above, you can see the override is on (fourth amber override led is on). The voltage is below the minimum amount because the “safety ok” led is off. And you can also see the “low voltage” red blink led is on. Note that the “safety stop” button won’t work when override is on, the voltage monitor circuit will always show the battery voltage status.

Different brightness settings

I created three different brightness settings. Called “phase 1, phase 2 and phase 3″. Phase 1 uses only 3 led’s. That gives a very long lifetime, more than a day, but I never tried it. The brightness can be compared to a small 2x AA maglite. Phase 2 has 100 led’s, phase 3 all led’s. Those three modes can be operated with switches and/or push buttons. A combinations is also possible. With the switches you can simply turn on and of the led groups. You can switch on only phase 3, wish also powers phase 1 and 2 on. You can also switch all three groups on, and when you then turn of group 3, group 1 and 2 automatically stays on. This is achieved with relais. With the pushbuttons you can push a led group on, and when releasing the button, the led group turns off. You can signal morse code with a simple lightly to push pushbutton. Mush easier than a heavy switch. You can also combine switches and pushbuttons. For example. You can switch on phase 1 and 2. And use a pushbutton to signal with group 3. Or you walking in the forest on only group 1 or 1+2. And you want a little more light to see something hard to see on current brightness, then you only have to push group 2 or 3 for a “little” more light temporarily.

Optional external device

The last controls to be seen are for an external device. To make the flashlight a little more versatile, I added a fourth “phase like” switch and pushbutton with next to it a power plug hole. The same plug type as the charger. With this plug you can power on and off the 12v output on that plug. It may come in handy some day. The only thing I tried using the plug for is a single white led to light up the control panel. You can also plug in a external 12v source. The “charger/system” switch should be on charger to make sure the battery inside the flashlight is disconnected to the flashlight system. Every 12v source should work, even a small 9v battery will light this flashlight, but not at full power. But still an amazing amount of light from a 9v battery. A car’s sigaret plug could be used to. And will last verry long. The battery used inside the flashlight only has 7Ah. A car battery can have 100Ah.

That’s the control panel explained in detail. You can see on the youtube clip on 1:12 to 1:44 the controls being used, after you have read this page you should understand this clip fragment allot better. It may seem complicated, but it’s very useful, and make this build much more pro like (that’s my opinion). I have never build any “complicated” circuits, and I liked to take the challenge to build a fully working control panel with relails and voltage control circuit. And it works surprisingly well, no defects what so ever, very durable build circuits and control panel, I guess.