Help!! Battery problem or charger problem?

[flying88]

I bought a pair of solarforce protected 3.7v RCR123a batteries from ebay and received them today. I tried them in my new Quark mini 123 flashlight. One battery works fine. The other one only works 0.1 second then the light goes off, what i means is that when I turned on the flashlight, there is a blink of light, then the light gradually goes off. At first, I thought I may need to charge the battery. So, I tried to put the battery into my DSD charger and then plugged in (I got the DSD charger from DX and it's the first time for me to use it, i followed the instruction of "plugging in after inserting battery" that i read somewhere from this forum). The indicator light turns solid green, but with casual blink of red, that is, there is a blink of red for around every 15-20 seconds. I am not sure whether it is charging or not. Anyway, after around 10 minutes, I get the battery out and then try it again in the flashlight, the problem still exists: there is only a blink of light, then the light gradually goes off. I really don't know what's going wrong here. Is the battery defective or does the charger have problem? Does anybody have any idea about the possible reasons? Thanks for help!

[irv_usc]

Generally a switching green/red blinking indicates a bad battery.

[flying88]

Thanks!! I also agreed that the battery may be problematic. Now, the strange thing to me is that every time I insert the "bad" battery into the flashlight, there is still a blink of light, then the light goes off. If the battery is totally dead, then there should be no light at all. That's kind of weird.

[45/70]

What is the open circuit voltage of the cell you are trying to charge? What is the voltage before and after you charge the cell. If you don't have a means to measure the cell's voltage, you should get a DMM, or some means to determine voltage. A DMM, or other way to measure voltage reasonably accurately, is a requirement before attempting to use Li-Ion cells in flashlights.

I'll also mention that fleaBay is not a good place to buy batteries. An awful lot of them are seconds, used, or just plain junk. Also, the DSD charger is one of the worst chargers available for charging Li-Ion cells. I know, I have one. This opens up the possibility that either your cell, the charger, or both are at fault, but I'm leaning towards the problem being a bad cell.

Dave

[flying88]

45/70, thanks for your suggestions. I currently don't have any device to measure the voltage, I may get one pretty soon. This is my first time to buy rcr123a batteries and charger and I don't have much experience. Next time, I will definitely buy more reliable ones.

[mfm]

. So, I tried to put the battery into my DSD charger and then plugged in (I got the DSD charger from DX and it's the first time for me to use it, i followed the instruction of "plugging in after inserting battery" that i read somewhere from this forum). The indicator light turns solid green, but with casual blink of red, that is, there is a blink of red for around every 15-20 seconds. I am not sure whether it is charging or not. Anyway, after around 10 minutes, I get the battery out and then try it again in the flashlight, the problem still exists: there is only a blink of light, then the light gradually goes off. I really don't know what's going wrong here. Is the battery defective or does the charger have problem? Does anybody have any idea about the possible reasons? Thanks for help!

1. What happens when you try to charge the other battery? You should always charge new Li-ions fully before using them, they are not fully charged from the manufacturer.
2. If it is only a quick blink every 20 seconds then it could probably be charging, the (real) WF-139 charger works like that I think.
3. Ten minutes charge is nothing, and so it will not tell you anything.

[march.brown]

If you live in the UK, then Maplins have cheap Digital Meters for five pounds ... If you live in America, they are half the price.

There is no way that you can even guess the cell voltage or charger voltage, so that makes a Voltmeter absolutely essential ... Even if you live next door to the Fire-Station, I would still recommend that you get a meter.

Listen to what Dave (45/70) says, he knows a lot more about these things than most of us.

By the way .... What happens when you charge the good battery ? ... Discharge it in the torch for about twenty minutes then put it on charge ... If the charger is OK and the good cell is OK then the red LED should come on ... This is what the other (faulty ?) battery should do.

I wonder if the protection circuit has tripped on that cell with the voltage being perhaps too low ? ... 45/70 will know the answer to this possibility.

[45/70]

I wonder if the protection circuit has tripped on that cell with the voltage being perhaps too low ? ... 45/70 will know the answer to this possibility.

Good point. It could be a faulty protection circuit, that trips as soon as the light is turned on. As I said, I'm leaning towards the cell, being the problem. If the charger charges the "good" cell, the charger is apparently working to some degree. Voltage readings before and after charging/using would really be helpful.

Dave

[flying88]

Thanks all for invaluable suggestions. For satefy, I will definitely get a digital multimeter. I am living in US. It seems Maplins only sells in UK, I will probably buy a DMM from some local electronic store.

I have tried to charge the other battery (the good one) after I used that battery in the flashlight for a few minutes. That battery seems to be charged fine in the DSD charger: the indicator is constan red.

When I put the "bad" battery into the charger and plugged in, the indicator was constant green with a blink of red for every 20 seconds. I was not sure whether it was charging or not and worried it may explode if I "charged" it too long. That's why i "charged" it for only 10 minutes. I believe I can do more experiments safely after I get a DMM and see what is going to happen.

[march.brown]

In the USA, the popular cheap DMM is from "Harbor Freight" at about five dollars.

[march.brown]

Good point. It could be a faulty protection circuit, that trips as soon as the light is turned on. As I said, I'm leaning towards the cell, being the problem. If the charger charges the "good" cell, the charger is apparently working to some degree. Voltage readings before and after charging/using would really be helpful.

Dave

Hi Dave, Do you think that putting the good cell in parallel with the bad one momentarily, might reset the protection on the bad one ?

You have a far better depth of knowledge than most of us, so I thought I would ask you first before suggesting it to the OP ... The charger probably doesn't come on at 4.2 volts initially as it should be in the constant current part of the charging cycle ... So the charger won't reset the trip.
.

[45/70]

Hi Dave, Do you think that putting the good cell in parallel with the bad one momentarily, might reset the protection on the bad one ?

march, the cell's protection circuit is resetting (if, it is even tripping at all), otherwise the cell wouldn't be able to work for the tenth of a second that it does. It could be the protection circuit tripping under load, or it could be that the cell just doesn't have any "oomph". As for what the actual problem really is, we need more information, voltage readings for starters.

Dave

[flying88]

Hi march, thanks for recommending the "Harbor Freight" store. I searched the nearest "Harbor Freight" and went there today. It looks I am lucky since they have some multimeters on sale today. I bought a "Cen-Tech 7 function multi-meter" for only 2.99 (regular is 7.99).

I tested both the good battery and the bad battery. The good one has a voltage of 4.11v. The bad one has a voltage of 3.91v. I then tried to charge the good battery in the DSD charger. The indicator was constant red. Around 7-8 minutes later, it began to quickly flash (red/green). I took the battery out and measured the voltage, it was 4.18v. I also tried to "charge" the bad battery. The indicator was still constant green with casual blink of red. (Today, i have a closer observation and found that the interval between two red blinks actually increases as the charging time increases. That is, at the beginning of "charge", there is two or three quick blink of red, then the interval of blink of red becomes around 4-5 seconds. Half minute later, the interval increases to around 10 seconds. 1 minute later, the interval increases to around 15 seconds. There is little change after that). Anyway, after charging the bad battery for around 10 minutes, I pulled it out and the measured voltage is 4.05v. I put the battery into the flashlight, the problem still exists: there is only a blink of light, then the light dims off.

[march.brown]

Hi march, thanks for recommending the "Harbor Freight" store. I searched the nearest "Harbor Freight" and went there today. It looks I am lucky since they have some multimeters on sale today. I bought a "Cen-Tech 7 function multi-meter" for only 2.99 (regular is 7.99).

I tested both the good battery and the bad battery. The good one has a voltage of 4.11v. The bad one has a voltage of 3.91v. I then tried to charge the good battery in the DSD charger. The indicator was constant red. Around 7-8 minutes later, it began to quickly flash (red/green). I took the battery out and measured the voltage, it was 4.18v. I also tried to "charge" the bad battery. The indicator was still constant green with casual blink of red. (Today, i have a closer observation and found that the interval between two red blinks actually increases as the charging time increases. That is, at the beginning of "charge", there is two or three quick blink of red, then the interval of blink of red becomes around 4-5 seconds. Half minute later, the interval increases to around 10 seconds. 1 minute later, the interval increases to around 15 seconds. There is little change after that). Anyway, after charging the bad battery for around 10 minutes, I pulled it out and the measured voltage is 4.05v. I put the battery into the flashlight, the problem still exists: there is only a blink of light, then the light dims off.

.
I think that I would give up on the bad battery and dispose of it safely ... See what Dave says though.

I would try putting the good one back on charge and remove every 15 minutes to check the voltage ... I would expect at some time, if the charger is working OK, for the green LED to come on ... If the voltage is 4.22 volts and the LED is still red then I would consider either getting another charger or at the very least check the voltage regularly and remove the cells when you reach 4.20 volts ... Don't go over 4.22 volts as the cells protection might cut in.

Can you try to measure the voltage of the charger output without a battery in ? ... Some chargers have volts present and some don't ... If you can measure a voltage then this is the maximum that the charger will bring the battery up to ... One of my chargers reads 4.22 volts when the green LED comes on but the cell doesn't seem to go over 4.21 volts ... Probably if I left it for a lot longer it would reach the 4.22 volts, but ideally the battery should be taken off at no more than 4.20 volts.

Glad you've got a meter at last.

Good luck.
.

[flying88]

I tried to measured the voltage of the charger without battery. The voltage is between 6.6 to 6.7v (I couldn't precisely read the voltage since the number changes rapidly). Does this mean there is no protection in the charger?

[45/70]

I tried to measured the voltage of the charger without battery. The voltage is between 6.6 to 6.7v (I couldn't precisely read the voltage since the number changes rapidly). Does this mean there is no protection in the charger?

As I said, the DSD is far from being a good charger, I'd pretty much rate it in the POS category. They usually have an open circuit voltage between 5-6 Volts. The reason it varies when you take a reading, is due to the electronics involved. A proper charger will never expose the cell to more than ~4.25 (ideally, 4.20) Volts, so yes, this means there is no protection built into the charger. That said, most of the "cheapo" chargers have an improper voltage, as they don't use a proper algorithm.

From your voltage tests, I would conclude that your problem cell has a defective protection circuit. It is not allowing proper current flow into, or out of the cell. I would give up on it. It may, or may not be safe, but in any case, it isn't good for anything anyway.

Now that you have a DMM, if you haven't already, you may want to give HKJ's thread a look, as it pertains to using one with flashlights/torches. Also, I don't know how familiar you are with Li-Ion cells in general, but I would strongly recommend reading the threads relevant to Li-Ion cells, in the "Threads of Interest" sticky and, the "Smoke and Fire" threads at the top of this forum. Knowledge is wisdom and wisdom is ..... I can never remember the rest of it, but you'll be safer and a lot better off, the more you know about them.

Dave

[flying88]

As I said, the DSD is far from being a good charger, I'd pretty much rate it in the POS category. They usually have an open circuit voltage between 5-6 Volts. The reason it varies when you take a reading, is due to the electronics involved. A proper charger will never expose the cell to more than ~4.25 (ideally, 4.20) Volts, so yes, this means there is no protection built into the charger. That said, most of the "cheapo" chargers have an improper voltage, as they don't use a proper algorithm.

From your voltage tests, I would conclude that your problem cell has a defective protection circuit. It is not allowing proper current flow into, or out of the cell. I would give up on it. It may, or may not be safe, but in any case, it isn't good for anything anyway.

Now that you have a DMM, if you haven't already, you may want to give HKJ's thread a look, as it pertains to using one with flashlights/torches. Also, I don't know how familiar you are with Li-Ion cells in general, but I would strongly recommend reading the threads relevant to Li-Ion cells, in the "Threads of Interest" sticky and, the "Smoke and Fire" threads at the top of this forum. Knowledge is wisdom and wisdom is ..... I can never remember the rest of it, but you'll be safer and a lot better off, the more you know about them.

Dave

Dave, thanks for recommending me the threads about the DMM and the li-ion battery. I have little knowledge about li-ion battery and those threads will definitely be helpful to me.

I will not use that defective battery any more. Again, thanks all for helping me to figure out the problem.