lctorana
Flashlight Enthusiast
Serious flashaholics, look away now.
I purchased a 128 LED torch from Hong Kong on eBay.
Cost was US$21.98 delivered, including 6xAA batteries fitted in 2 carriers.
Worked nicely straight out of the airmail packet, lighting up the room in BROAD DAYLIGHT.
Impressive, and almost astonishingly bright.
The casing is made of really heavy-gauge metal, and it would take real determination to damage it.
What follows is a tale of woe, and a lesson with a moral.
I hate battery carriers, so before the evening was out, I had the 6AA replaced with 2x18650, with suitable radial padding, to give me the brightest torch I have ever seen.
The 128 LED torch is a floodlight. It has a flat glass over the proverbial "shower head" configuration, which gives a satisfying flood of light in an almost cardioid pattern - no focus, no bright spot, just *lots* of illumination.
What is this useful for?
We've all either had to work on a car in the dark, or had to hold the torch for someone who is. And the task of holding the bright spot on just the right spot is very hard. But with a shower head, the problem just goes away.
So straight into the car this went. I bought it for a toy, but to say it exceeded my expectations was an understatement.
Tale of woe still coming.
Before I put it in the car, I measured the current draw at over 3 amps!
The very next night, my car broke down. In the dark. In the rain. And the 128LED stopped working.
My fault.
(Car needed a new ignition coil,FWIW)
Later that night, opened up the 128 to see...
...everything between the switch and the head a solidified lump of molten plastic.
Time to dismantle the head, and examine the circuit.
Basically, all 128 LEDs are in parallel.
That means the torch is looking for 3.5V @ 128*0.03=3.84A.
No $#&%*@! wonder that:
And I replaced them with 2x18650 which would have pumped out a good solid 7V or more - DOUBLE what the LEDs required - and a fair amount of that was dropped in the connectors, hence all the heat.
And yes, it did smell.
So, what did I do?
First, how to power it. You don't treat AA batteries like that, and I don't like a solution that first stresses the LEDs and then the batteries, in normal use. We can do better than that.
The voltage requirement is for 3.5V (max 4V) which is neatly supplied by 3 NiCd batteries, which provide 3.75 initially, falling to 3.6V for most of the discharge period.
Perfect, especially as there will be a few milliohms in the wiring. I did consider a (very) low-value resistor in the head, but not for long. Remembered that the LEDs are rated to handle 4V input anyway, and NiCds won't reach that off-charge and under load.
The barrel is wide enough for C cells, but not long enough for three of them, but 3 sub-C cells are *exactly* the right length. A bit of radial padding (some woollen plaid material rolled up) around 3 brand-new 2000mAh sub-C NiCds, and that's sorted.
Why NiCd? Because this will be a standby for breakdowns, and I want low self-discharge.
The rest was easy. Soldered a long wire from the head to a standard spade lug, suitably insulated, joined up, and voila! My shower head torch restored!
Current draw is now just over an amp, so the LEDs are each doing it easy at a mere 8mA each, and I should be able to expect a 2-hour runtime, enough for most roadside fixes.
Brightness, despite the drop in current, is more than adequate.
I believe the mods (sub-C rechargables and hard-wiring the head to the switch) have both greatly improved the torch, and with these done, I would recommend it.
It has a well-made head, with all 128 LEDs giving equal brightness on my example, and a really good casing.
Plus, I have shown it can stand some electrical abuse.
But in its standard form, with 6AA batteries and flimsy connectors between head and switch, it's a bit dodgy.
The moral of the story?
1. When buying a no-name brand LED torch, don't assume the supplied battery configuration is optimal, or even correct!
2. Before modding a torch to different batteries, dismantle the torch and see what makes it tick. Don't just assume, like I did!
I'll try to post beamshots when I figure out how to do it.
I purchased a 128 LED torch from Hong Kong on eBay.
Cost was US$21.98 delivered, including 6xAA batteries fitted in 2 carriers.
Worked nicely straight out of the airmail packet, lighting up the room in BROAD DAYLIGHT.
Impressive, and almost astonishingly bright.
The casing is made of really heavy-gauge metal, and it would take real determination to damage it.
What follows is a tale of woe, and a lesson with a moral.
I hate battery carriers, so before the evening was out, I had the 6AA replaced with 2x18650, with suitable radial padding, to give me the brightest torch I have ever seen.
The 128 LED torch is a floodlight. It has a flat glass over the proverbial "shower head" configuration, which gives a satisfying flood of light in an almost cardioid pattern - no focus, no bright spot, just *lots* of illumination.
What is this useful for?
We've all either had to work on a car in the dark, or had to hold the torch for someone who is. And the task of holding the bright spot on just the right spot is very hard. But with a shower head, the problem just goes away.
So straight into the car this went. I bought it for a toy, but to say it exceeded my expectations was an understatement.
Tale of woe still coming.
Before I put it in the car, I measured the current draw at over 3 amps!
The very next night, my car broke down. In the dark. In the rain. And the 128LED stopped working.
My fault.
(Car needed a new ignition coil,FWIW)
Later that night, opened up the 128 to see...
...everything between the switch and the head a solidified lump of molten plastic.
Time to dismantle the head, and examine the circuit.
Basically, all 128 LEDs are in parallel.
That means the torch is looking for 3.5V @ 128*0.03=3.84A.
No $#&%*@! wonder that:
- the torch is BRIGHT
- the connections melted.
And I replaced them with 2x18650 which would have pumped out a good solid 7V or more - DOUBLE what the LEDs required - and a fair amount of that was dropped in the connectors, hence all the heat.
And yes, it did smell.
So, what did I do?
First, how to power it. You don't treat AA batteries like that, and I don't like a solution that first stresses the LEDs and then the batteries, in normal use. We can do better than that.
The voltage requirement is for 3.5V (max 4V) which is neatly supplied by 3 NiCd batteries, which provide 3.75 initially, falling to 3.6V for most of the discharge period.
Perfect, especially as there will be a few milliohms in the wiring. I did consider a (very) low-value resistor in the head, but not for long. Remembered that the LEDs are rated to handle 4V input anyway, and NiCds won't reach that off-charge and under load.
The barrel is wide enough for C cells, but not long enough for three of them, but 3 sub-C cells are *exactly* the right length. A bit of radial padding (some woollen plaid material rolled up) around 3 brand-new 2000mAh sub-C NiCds, and that's sorted.
Why NiCd? Because this will be a standby for breakdowns, and I want low self-discharge.
The rest was easy. Soldered a long wire from the head to a standard spade lug, suitably insulated, joined up, and voila! My shower head torch restored!
Current draw is now just over an amp, so the LEDs are each doing it easy at a mere 8mA each, and I should be able to expect a 2-hour runtime, enough for most roadside fixes.
Brightness, despite the drop in current, is more than adequate.
I believe the mods (sub-C rechargables and hard-wiring the head to the switch) have both greatly improved the torch, and with these done, I would recommend it.
It has a well-made head, with all 128 LEDs giving equal brightness on my example, and a really good casing.
Plus, I have shown it can stand some electrical abuse.
But in its standard form, with 6AA batteries and flimsy connectors between head and switch, it's a bit dodgy.
The moral of the story?
1. When buying a no-name brand LED torch, don't assume the supplied battery configuration is optimal, or even correct!
2. Before modding a torch to different batteries, dismantle the torch and see what makes it tick. Don't just assume, like I did!
I'll try to post beamshots when I figure out how to do it.
Last edited:
