How to Test a Charger?

[VapourMonkey]

Following on from the events of the past 24 hours, I have seen recommendations to test your batteries and charger outputs.
I have always made a habit of checking the voltage of batteries, before and after charging but can anyone explain how i test the charger output?

My charger is a Trustfire TR001 and i use AW IMR 18490 batteries.

Apologies if there is already a thread out there but i have searched and could not find any.

Paul

 

[VapourMonkey]

bump in case anyone missed who can explain.

 

[evilferret]

You can use the multimeter to check output on the charger.

Should be 4.2 ish v's if its working properly. This reminds me to test mine.

http://www.e-cigarette-forum.com/forum/battery-issues/51621-battery-chargers-messing-my-mind.html

 

[Nomoreash]

IMR batteries don't have any protection so the max charge would depend on the chargers cut off point. If they are measuring 4.2 or slightly below fresh off a charge your Trustfire TR001 should be performing properly. Also check for heat, if the battery is getting hot when charging that would need further investigation as to whether it was a battery or charger issue.

 

[evilferret]

IMR batteries don't have any protection so the max charge would depend on the chargers cut off point. If they are measuring 4.2 or slightly below fresh off a charge your Trustfire TR001 should be performing properly. Also check for heat, if the battery is getting hot when charging that would need further investigation as to whether it was a battery or charger issue.

Just put the battery in the charger and measure in-line. If it reads 4.2ish it should be good.

If the charger is overcharging, you won't know unless you test a fresh battery.

 

[VapourMonkey]

Thanks for the responses guys.
My IMR 18490 are coming off around the 4.15v mark so I presume everything is as it should be.
Nomoreash, yes that is something I make a habit off, checking if they are getting warm while they are charging.
evilferret, sorry to sound dumb but by measuring in-line, do you mean measuring across the terminals of the charger with a battery in place that has reached full charge (green light on)?

 

[stephpd]

From what I've been reading there are 2 things to look out for with a charger.

The first is overcharging. Anything over 4.25 volts seems to be to much for the battery and can make them unsafe when they first get used.

The other is charging at to fast a rate and can cause the battery to explode while charging. From what I've been reading on the CPF forum it should never be higher then 70% of 1C (did I say that right? 1C being the mAh rating on the side of the battery, if it's actually true, many aren't.) So for smaller batteries, like the Ego 650 a 500 mAh charger would be too much. Better to use a 300 mAh charger for those. Smaller cigarette sized ones would use even lower rated chargers.

For most of the 18650 type batteries (some rated for 3100 mAh) it can be very high charge rates. But most of the chargers we are purchasing are only 500-650 mAh and shouldn't pose any problem with the large batteries.

There's also the way they charge a battery. There's supposed to be a unusual curve (cc/cv) that charges most of the way to fully charged, then the last little bit it's supposed to go much slower. Most of the cheap ones we are purchasing don't seem to be following this curve.

The Xtar do seem to follow this curve.
Super T Manufacturing, Innovative manufacturer of electronic cigarette products.

 

[evilferret]

Thanks for the responses guys.
My IMR 18490 are coming off around the 4.15v mark so I presume everything is as it should be.
Nomoreash, yes that is something I make a habit off, checking if they are getting warm while they are charging.
evilferret, sorry to sound dumb but by measuring in-line, do you mean measuring across the terminals of the charger with a battery in place that has reached full charge (green light on)?

To test the proper way, they have dummy batteries which you plug in and than measure.

I just put in the battery into the charger than measure from the batt contacts. This way you can check the voltage being applied to the battery directly.

If you got a fancy meter you can even test the mAh and see how fast it charges.

I'm not sure but I think the TR001 overcharges even when it says its done charging. Might want to read into it. I bought a Pila so I don't have to be so paranoid while charging batteries during the last battery scare.

 

[Rocketman]

So for smaller batteries, like the Ego 650 a 500 mAh charger would be too much. Better to use a 300 mAh charger for those. Smaller cigarette sized ones would use even lower rated chargers.

Most of the cheap ones we are purchasing don't seem to be following this curve.

I'm going to slightly disagree with you on a couple points.
USE THE CHARGER THAT CAME WITH YOUR EGO. Using a lower rated charger may overload the charger. Damage the charger and it may not be safe to use. I believe the name brand eGo chargers are rated @420ma. Do not get your chargers mixed up if you vape mini e-cigs and eGo (or clones).


Laptop chargers inside the laptop (the power supply adapter is outside) don't follow that curve. Neither do cellphone chargers. They do a CC/CV curve, but not the 4 step that is the cat's meow. The TR-001 that I have does not trickle charge. To determine if a charger trickle charges charge up a good cell monitoring the voltage (do not remove the cell to measure) when the green LED comes on. Let the cell remain in the charger for another hour. The cell voltage will peak, then start to fall. At some point the charger will kick back in to top off the cell. Leaving a cell in the chargers for many hours past the Green LED is not good as this repeated topping off passes a worthless small current to the cell that does nothing but 'wear out the chemistry' and make the cell old and potentially unstable when used. But that is not
trickle charging. If the cell voltage continues up after the green led comes on, that is trickle charging. You better hope it stops.


Open circuit voltage (no load on charger) is not a good way to test. This is only a test voltage on some smart chargers. Once the charger detects a cell it will go into charge mode.

 

[VapourMonkey]

...

I'm not sure but I think the TR001 overcharges even when it says its done charging. Might want to read into it. I bought a Pila so I don't have to be so paranoid while charging batteries during the last battery scare.

Thanks evilferret.
From what i have read, it seems to be the earlier models that flashed red while charging that tended to overcharge.
The batteries are coming off the charger around 4.15-4.17 volts so I don't think it's an issue with this charger.
I am looking for a Pila charger but they do appear to be as rare as rocking horse droppings at the moment (UK anyway)

 

[VapourMonkey]

Open circuit voltage (no load on charger) is not a good way to test. This is only a test voltage on some smart chargers. Once the charger detects a cell it will go into charge mode.

Thanks Rocketman, yes that was what i suspected would happen without a battery.
I make a point of fetching batteries straight off the charger when they turn green, I would do the same if it was a Pila even. I think it's best to be on safe side.

 

[Rocketman]

Checking your batteries, and chargers and watching for something to change is a good way to catch a defect.
It's like watching the temperature gauge in your car to establish 'normal'.
Something changes, something is wrong.
Vape life of a cell goes down, green LED takes forever to go off, or goes off before cell is fully charged, charges a little higher or lower than when new, something might be wrong.

Steam coming out from under the hood is TOO LATE

 

[Sad Society]

I also had some concerns about IMR 18650 batteries when I was looking into getting a new VV mod that uses those type of batteries.

ECF members recommended to use a Ultrafire WF-188 Charger for those who couldn't afford a Pila charger. I did some testing on this charger on the IMR batteries along with a cheap no name brand charger that I already had with a multimeter.

The Ultrafire WF-188 charges the battery a lot slower, but it will charge the battery all the way to 4.25 and stops (thats with leaving the battery in the charger even after it is charged).

My cheapo charger charges the battery a lot faster and even with leaving the battery past the charging point (it doesn't overcharge it), it charges it to 4.21 (the mulimeter reading)

Both chargers are 500 mah output.

Right now I use my cheap charger (some no name brand I got off Ebay) to charge my IMR's because it charges them quicker. And I have my Ultrafire WF-188 Charger as a back up.

I left the batteries in the charger even though the charger light was green just for the test to see if they would be overcharged.

Battery safety comes first. I never leave my batteries charging unattended. I unplug the charger when I'm not around. And I take the battery out when it's charged.

 

[Rocketman]

Sad,
I think it's great that you Know what your equipment is doing.
IMR cell resistance fools the termination point of some chargers.

Measuring voltages can find defective NEW items (does happen)
but establishes a BASELINE to monitor.

No need to be paranoid, but knowledge is good.

 

[Bozzlite]

Charging lithium batteries past 4.20 volts is not good. Charging to 4.25 volts is really, really, pushing it.

Not only is it hard on the battery, but creates a dangerous overcharge situation which could lead to venting with flames at the first push of the button. The IMR's are less likely to do that, but remember, they have no overcharge protection circuitry.

 

[Sad Society]

Charging lithium batteries past 4.20 volts is not good. Charging to 4.25 volts is really, really, pushing it.

Not only is it hard on the battery, but creates a dangerous overcharge situation which could lead to venting with flames at the first push of the button. The IMR's are less likely to do that, but remember, they have no overcharge protection circuitry.

Thats why I use my cheap charger. I always test a freshly charged battery before I using it and it usually reads around 4.1

 

[Rocketman]

How about taking a cell straight from the charger and vaping away?

Let the cell cool, settle down, then use it.

There will be some temperature rise when charging (hot is bad of course) but taking a 'warm' cell straight from the charger and vaping on it just heats it up more.

 

[Codrut Popescu]

To test the proper way, they have dummy batteries which you plug in and than measure.

I just put in the battery into the charger than measure from the batt contacts. This way you can check the voltage being applied to the battery directly.

If you got a fancy meter you can even test the mAh and see how fast it charges.

I'm not sure but I think the TR001 overcharges even when it says its done charging. Might want to read into it. I bought a Pila so I don't have to be so paranoid while charging batteries during the last battery scare.

I do own a Fluke 175 (don't ask why I do own one, I am not sure either) and I have measured the voltage on the TR-0001 without batteries and it reads 4.229 V. I did not test with the batteries in yet.

You have mentioned you can test the mAh. How? I have set my multimeter to read mA - DC and the charger goes from green LED to red LED for a second and then disconnects going back to green again. Should I test with the batteries in?

Does anybody else hear the TR-0001 buzzing when connected to the power grid? Is this normal?

Thanks
Codrut

 

[stephpd]

I'm going to slightly disagree with you on a couple points.
USE THE CHARGER THAT CAME WITH YOUR EGO. Using a lower rated charger may overload the charger. Damage the charger and it may not be safe to use. I believe the name brand eGo chargers are rated @420ma. Do not get your chargers mixed up if you vape mini e-cigs and eGo (or clones).

Not sure if that's true. A smaller mAh rated charger will only put out the maximum rated amperage. It just takes longer for higher mAh batteries to charge.

As an example lets look at a couple 18650 batteries and charging them on a simple multi charger like a Trustfire. I've got Imr's rated as low as 1600 mAh as well as 2400 and 3100 mAh batteries (and a couple 14500's rated @1100 mAh) . On the charger, rated at 500 mAh they all receive far below the CC/CV curve for the first stage.

The 1600 takes 3-4 hours to charge. The 3100 mAh can take well over 8 hours to get fully charged. And I've not seen anywhere that this could hurt the charger or batteries. I could be wrong, so if you have a link providing this information it would be greatly appreciated.

 

[Playa_hamm420]

Bump Cause everyone should be using a multimeter to check there stuff!