I have a quark 123 in which I use BS rechargeable 3.6v. The light and batts are only a couple of months old. Recently I noticed that after about thirty seconds of continuous on high the light shuts off. I tried it with four different BS rechargeables and the problem remained the same. When used with a duracell primary the problem resolves. Is this a problem of the battery getting too hot and the protection circuit shutting down? I can turn the light off then back on and it does the same thing again. This occurs whether the batteries are freshly charged, allowed to sit 24 hours after charging or slightly drained. The batteries are not hot to the touch when removed immediatelyh after the malfunction. I'm fairly new to rechargeables so is this a battery or a light problem? I appreciate any help, thanks.
problem with quark 123
- Thread starter ishmael
- Start date
Help Support Candle Power Flashlight Forum
Billy Berue
Newly Enlightened
Almost certainly a battery issue. You might try measuring the voltage of the cell under load. A simple way to do so is to use a small resistor that simulates the load of your light.
Billy Berue
Newly Enlightened
If you have a Radio Shack nearby, you can pick up resistors in various shapes and sizes from there. I don't recall off hand the current draw of the Quark 123 on high, but let's assume it's 675mA. You can easily measure it for yourself with a decent DMM using the method that HKJ explains here.
Assuming a current of 675mA and a voltage of ~4.1v (with a healthy cell, there should be some modest voltage sag under load), then the light is providing ~6 ohms of resistance, and the cell is providing ~2.75 watts of power. You can check the math for yourself using an online Ohm's Law calculator like this one.
So, you could wire your cell to a 6-ohm resistor like this one to simulate the load imposed on the cell by your light, and then measure the voltage across the resistor using HKJ's guide, which I referenced earlier. For a freshly charged Li-Ion cell, it should stay near 4v. Try leaving the circuit connected for more than 30 seconds, and watch the meter readout over time. Is the voltage steadily dipping, or is it holding fairly constant? If dipping, then you have a bad cell.
Assuming a current of 675mA and a voltage of ~4.1v (with a healthy cell, there should be some modest voltage sag under load), then the light is providing ~6 ohms of resistance, and the cell is providing ~2.75 watts of power. You can check the math for yourself using an online Ohm's Law calculator like this one.
So, you could wire your cell to a 6-ohm resistor like this one to simulate the load imposed on the cell by your light, and then measure the voltage across the resistor using HKJ's guide, which I referenced earlier. For a freshly charged Li-Ion cell, it should stay near 4v. Try leaving the circuit connected for more than 30 seconds, and watch the meter readout over time. Is the voltage steadily dipping, or is it holding fairly constant? If dipping, then you have a bad cell.
Last edited:
Billy Berue
Newly Enlightened
I should hasten to add that, if the voltage of your cell is in fact dipping, then don't let it dip below 3.0 volts for more than a couple quick seconds. Disconnect the circuit to avoid potential meltdown of the cell. I'd hate to rely solely on the cell's on-board protection circuit.
oo:
Billy Berue
Newly Enlightened
OK, so it turns out that the Quark 123 draws a good bit less current from a freshly charged RCR123a on high. I just measured mine (which is the neutral white version) at ~270mA using a not-so-freshly charged RCR123a (w/ open voltage of 3.98v). You would need ~15 ohm resistor to simulate that load. I happen to have a 15-ohm resistor sitting around, so when I connect that to my RCR123a, I measure a voltage of ~3.78v across the resistor. So the voltage sag is ~0.20v with that load.
