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Is there a problem?

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boswell3782

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Hi, I have a 200mw green focusable laser bought from Dailyshop (Dinodirect Subsidiary).

Received it yesterday morning and had a little play with it. Tried it again this morning, about 20-30 mins of pointing it outside was going good until I came back inside and started pointing it around my bedroom it suddenly started slowly going dim then it died. If I wait around 5 mins it will go back to bright then slowly die again after about 2 seconds. If I hold the button when the green light disappears the diode shows red IR (I didn't look straight at it I looked through my laptop webcam).

I have checked the battery in my multi-meter and it is pretty much empty around 2.5v (18650) and slowly creeps up to around 2.7v after a few minutes.

Is this normal for a laser to show IR when battery is low or is there a problem?

Thanks!
 





chipdouglas

chipdouglas

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An 18650 is a 3.7 volt dc battery. At full charge it is 4.2v. You cut off voltage is around 3. If your are going lower than that, then that is your problem. You probably have a damaged battery. If it is not in the 4.0 to 4.2 range at full charge get a new battery
 
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Stix62

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Perfectly normal, you've dropped below the working voltage for the laser, re-charge the damn battery!
 
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B

boswell3782

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chipdouglas said:
An 18650 is a 3.7 volt dc battery. At full charge it is 4.2v. You cut off voltage is around 3. If your are going lower than that, then that is your problem. You probably have a damaged battery. If it is not in the 4.0 to 4.2 range at full charge get a new battery
Click to expand...

It says on the battery 2.7v is the voltage it would be at when it is empty?

Stix62 said:
Perfectly normal, you've dropped below the working voltage for the laser, re-charge the damn battery!
Click to expand...

I have just ordered a charger for it because it didn't come with one.
 
B

boswell3782

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UPDATE: After about an hour the battery is now at 3.05v but if I put it back in the laser and use it, it will go back down to around 2.7v.
 
lasersbee

lasersbee

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boswell3782 said:
Hi, I have a 200mw green focusable laser bought from Dailyshop (Dinodirect Subsidiary).
If I hold the button when the green light disappears the diode shows red IR (I didn't look straight at it I looked through my laptop webcam).
Click to expand...

So... you say that you saw the "diode show red IR on your laptop webcam...:thinking:

boswell3782 said:
UPDATE: After about an hour the battery is now at 3.05v but if I put it back in the laser and use it, it will go back down to around 2.7v.
Click to expand...

Part of the problem is the operator....

I hope you have Laser Safety Goggles/Glasses for your
200mW Laser...

CHARGE YOUR BATTERY BEFORE USING IT AGAIN !!!

You are damaging the battery by depleting it again and again...

CHARGE YOUR BATTERY BEFORE USING IT AGAIN !!!


Jerry
 
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boswell3782

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lasersbee said:
You are damaging the battery by depleting it again and again...
Click to expand...

Oh. I never thought of that. With the new charger I ordered you get 2 new batteries with it anyways so I'll try/compare them to see if it is a defective battery that is causing the problem. Thanks.
 
Hiemal

Hiemal

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Buddy, Lithium ion batteries have a rough working voltage from 4.2 (fully charged) to around 3 volts completely discharged.

You cannot keep running your batteries that low. They're rechargeable for a reason, so recharge them! They're not single use batteries.

When your laser gets that low, recharge them, otherwise you run the risk of damaging your batteries.
 
bloompyle

bloompyle

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lasersbee said:
So... you say that you saw the "diode show red IR on your laptop webcam...:thinking:



Part of the problem is the operator....

I hope you have Laser Safety Goggles/Glasses for your
200mW Laser...

CHARGE YOUR BATTERY BEFORE USING IT AGAIN !!!

You are damaging the battery by depleting it again and again...

CHARGE YOUR BATTERY BEFORE USING IT AGAIN !!!


Jerry
Click to expand...


On some webcams, you can view the IR. Mine shows IR as a blueish when coming from my greens(and I block the green) and straight from a diode it's kinda red with bright white light around it.

And just to beat this dead horse some more, charge the battery!
 
jeffreythe00

jeffreythe00

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If you need an 18650 battery I could send you one for cheap. This way you could have one charging while you use the other and you are not tempted to run the battery half dead in your shiny new laser.
 
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honeyx

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Not all 18650´s are totally empty at 3.6v or 3.0 V. Some can discharge up to 2.5V but should be charged as soon as possible. For 16340´s it is normal to discharge up to 2.75V. 18650 batteries that are below 3V should be triggle charged at a low current till they reach at least 3V. Or better up to 3.6V.

Should the voltage drop below 2V you shouldn´t recharge a Li-Ion battery anymore because it´s almost demaged and may explode.

So discharging a 18650 below 3V isn´t already killing it if it´s recharged after a short while, but you need a charger that trigglecharges it at least to 3V. All the cheap chargers don´t do that and that´s killing the battery finally.
 
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