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How are cheapo 18650 chargers supposed to work?

yawnny

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I just bought a laser that included 2 "Ultrafire" 18650 batteries, and 2 single incredibly cheap chargers for the same.

Just how how are the chargers supposed to work? After running both batteries down to approx 3.7 volts, I tried to charge them in the chargers. Both of the chargers just sit there and blink red. The Killawatt thingee that I have the chargers plugged into doesn't show any current being drawn. How does charger indicate that a battery is charging, charge complete, bad battery?

I know the batteries, and chargers are crap, but I have gotten ones in the past that at least worked. I plan on returning either the chargers or batteries, but I don't know if the charger is at fault since I have no clue what flashing red means.

Looked on line for instruction, but nothing specifically said what the indicator light signified.
 
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RB astro

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I just bought a laser that included 2 "Ultrafire" 18650 batteries, and 2 single incredibly cheap chargers for the same.

Just how how are the chargers supposed to work? After running both batteries down to approx 3.7 volts, I tried to charge them in the chargers. Both of the chargers just sit there and blink red. The Killawatt thingee that I have the chargers plugged into doesn't show any current being drawn. How does charger indicate that a battery is charging, charge complete, bad battery?

I know the batteries, and chargers are crap, but I have gotten ones in the past that at least worked. I plan on returning either the chargers or batteries, but I don't know if the charger is at fault since I have no clue what flashing red means.

Looked on line for instruction, but nothing specifically said what the indicator light signified.
Yawnny, get rid of them before they burn your house down.
Don't use them.
Check out this thread and many others about the dangers of these 'ultrafire' batteries below:

http://laserpointerforums.com/f67/w...-ever-buy-ultrafire-after-seeing-87108-8.html

RB
:beer:
 

Benm

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They can be dangerous, though explosions like that are rare. I would never leave them unsupervised though, don't whack batteries in them and leave the house or even room.

As for how they usually work: The cheapest chargers often have a dual-color led that flashes between red and green. When the cell is low it's red all/most of the time, and this gradually changes to mostly green as it charges up. When full it will stay lit green.

What this indicates is the charge process: when flashing between red and green, the cell is charged with constant current from about 3.7 to 4.2 volts. When it reaches 4.2 volts it goes to constant voltage mode keeping the cell at 4.2 volts.

Good chargers can do the same thing, but they will stop charging at some point, whereas the cheap ones will keep charging at 4.2 volts forever (no time-out circuit at all). This is not good as you should not trickle change lithium cells forever like you can with nihm and nicd cells.

If you have batteries with protection circuits in them it's possible they will not charge up at all when fully discharged. This is because that circuitry cuts the connection when the cell voltage drops below a certain value (could be 3.0 volts, could be 3.5 or anything). A charger can do nothing about this. If it happs i'd recommend just setting the batteries aside unconnected for 24 hours and then try again.
 

yawnny

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Yep, they are definitely crap, and I understand why. A nice man on Youtube took one apart, reverse engineered it's simple circuitry, and sketched out a schematic revealing it's shortcomings and possible dangers, (and curiously enough, even a diode to protect against reversed polarity).

In spite of it's cheapness, it should work on some level. I don't trust it as far as i can throw it, and will likely replace it at some point. In the meantime, I am going to return it until I get one that works because I aid for one that works, regardless of how crappy it is.

But, I don't feel right messaging the seller that his charger isn't working, if in fact it's supposed to be flashing red. No Chinglish instruction sheet at all. So, we are in total agreement, it's not a good charger, but I'm going to get a not good charger that works for a while.
 

yawnny

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Weird. I hauled out an older one of the same model charger, and it seems to glow a steady red with the batteries I just received. So, either they changed something since a year or so ago, or both of the new chargers are more broken than designed. Oh well.

OK, I'm done with them. The old charger is now flashing red, same as the new ones. Nothing seems hot, or charged, but I'm giving up. Thank all y'all for the sound advice.
 
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I have a grey ultra fire that is pretty heavy and has a low voltage cut off ( i ordered it years ago domestically) but the blue one i got with my red 301 was a joke I felt like I was gonna break it. Measure the voltage with voltmeter before you use it it should be 4.18 and take it out 5 mins after the batt shows charged if it's above 4.21 don't use the charger any good charger will never even get it to 4.20. They tend to keep them at 4.18. Don't use the blue ultrafire it cant even handle 1.89 amps it might be a smaller cell. Does sodium cholride help with lithium fires. I read it helps with other metals that are on fire?

baking soda won't

it goes to sodium carbonate water , and co2

water makes it worse
 
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yawnny

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I have a grey ultra fire that is pretty heavy and has a low voltage cut off ( i ordered it years ago domestically) but the blue one i got with my red 301 was a joke I felt like I was gonna break it. Measure the voltage with voltmeter before you use it it should be 4.18 and take it out 5 mins after the batt shows charged if it's above 4.21 don't use the charger any good charger will never even get it to 4.20. They tend to keep them at 4.18. Don't use the blue ultrafire it cant even handle 1.89 amps it might be a smaller cell. Does sodium cholride help with lithium fires. I read it helps with other metals that are on fire?

baking soda won't

it goes to sodium carbonate water , and co2

water makes it worse
I have given up on the weird bogus Ultrafire batteries, and chargers.

Before I did, I determined that the single battery chargers will charge the blue Ultrafires to 4.09 volts, then shut off, but the charger indicator light remains flashing. The one double battery charger that I have will charge a blue Ultrafire to 4.21, and then shut off. The indicator light changes to a solid green.

None of the batteries or chargers even get warm while charging, but charging takes some time. The last tests I did were outside, with the chargers resting on a round patio block, surrounded by four bricks. If the stupid things were going to reach critical mass, I had no intention of trying to put them out. No clue if salt would have been more effective than baking soda. They worry me.

I am currently looking, on online sites, for a combo offer with maybe 4 name brand batteries, and a decent charger.
 
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I have given up on the weird bogus Ultrafire batteries, and chargers.

Before I did, I determined that the single battery chargers will charge the blue Ultrafires to 4.09 volts, then shut off, but the charger indicator light remains flashing. The one double battery charger that I have will charge a blue Ultrafire to 4.21, and then shut off. The indicator light changes to a solid green.

None of the batteries or chargers even get warm while charging, but charging takes some time. The last tests I did were outside, with the chargers resting on a round patio block, surrounded by four bricks. If the stupid things were going to reach critical mass, I had no intention of trying to put them out. No clue if salt would have been more effective than baking soda. They worry me.

I am currently looking, on online sites, for a combo offer with maybe 4 name brand batteries, and a decent charger.


any brand name I.E sony or samsung unprotected with the nitecore i2 is good. it cuts at 4.18.


pretty sure the lighter ultrafire is a smaller cell. i'll weigh it later.


I read salt was good for other akali metals.


beware of fakes cause of e-cig sites saying it's a sony.
 

Antharak

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Look at the thread in my sig about cheap chargers. Smash them and throw them away.
 

Crazlaser

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As everyone is saying, buy a good charger. I own this Nitecore D2 and I like it. It cost me about $17. I owned a cheapo charger and when I opened it I found the charge status led was being powered by discharging the batteries, inside there was no transformer and the plug was coated with silicone.
 

AaronT

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I have a little XTAR MC1 Plus that is a dandy little unit for the price.

XTAR MC1

I plan to pick up a XTAR SV2 at a later date.
 




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