Help - blue battery dimensions

Looks like I`ve just become a serial offender. These arrived with this morning`s post, from a different supplier - 4 x 5Ah 18650 protected li-ions without tags.

1-IMG_7228.JPG

No instruction or safety leaflet with these. As you can see these are perfectly safe and reliable  ;)  ;)

"Designed to meet your need, it consumes less power and extends time so that it is ideal for long flights, outdoor activities, and business trips. Besides, it is Eco-friendly, safe and reliable enough to use. Don’t hesitate again, equip with this high quality battery."

http://www.ebay.co.uk/itm/201056896378


Rik
 
And they will send them world wide free post.... I'm keen to know if they are 5Ah....
 
Tramcar Trev said:
And they will send them world wide free post.... I'm keen to know if they are 5Ah....
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Sorry about the delay but been awaiting the delivery of the battery holders and then other things kept getting in the way. Three of the four charged up OK - couldn't get the fourth to hold a charge. Have discharged one battery so far at a steady 0.5amps (thought I'd play safe until I knew what I was dealing with) and it took 187 minutes. So, as we suspected 5Ah is somewhat of an exaggeration - nearer 1.5Ah. I will try discharging the other three to see what I get with those before I send an email to the supplier.

Rik
 
ge_rik said:
Sorry about the delay but been awaiting the delivery of the battery holders and then other things kept getting in the way. Three of the four charged up OK - couldn't get the fourth to hold a charge. Have discharged one battery so far at a steady 0.5amps (thought I'd play safe until I knew what I was dealing with) and it took 187 minutes. So, as we suspected 5Ah is somewhat of an exaggeration - nearer 1.5Ah. I will try discharging the other three to see what I get with those before I send an email to the supplier.

Rik
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Goods not as described - you should get a full refund. Dont leave it to long to open the dispute, I think 40 days is the statute of limitations...
 
ge_rik said:
. . .
Three of the four charged up OK - couldn't get the fourth to hold a charge. Have discharged one battery so far at a steady 0.5amps (thought I'd play safe until I knew what I was dealing with) and it took 187 minutes. So, as we suspected 5Ah is somewhat of an exaggeration - nearer 1.5Ah. I will try discharging the other three to see what I get with those before I send an email to the supplier.

Rik
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Just curious. How do you get a steady 0.5A discharge current? I had been thinking of an electronic load unit until I saw the prices!

And how did you time the discharge duration?
At C/10 discharge you were loading the cell at full rate (5Ah), not 'playing safe'. Or did they quote a different rate.

I 'tested' the cell in my malfunctioning flashlight (it was a problem with the focusing ring breaking connection, only - eventually - obvious when everything electrical tested OK). Over 17A through my Fluke DVM (on 10A range) so it was a very brief test! The cell is labeled 3.7V 800mAh incidentally. Anyone who thinks that it's no problem shipping these batteries by air IMHO has been watching the Dambusters movie far too often. These bombs do not need to bounce.

Don
 
Don get yourself one of these (or the generic equivalent); http://www.ebay.com.au/itm/360738305042?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_2665wt_1075
Takes all the guesswork out of the care and feeding of most rechargeable batteries, even can "rejuvenate" Nicads....
 
don9GLC said:
.......
At C/10 discharge you were loading the cell at full rate (5Ah), not 'playing safe'. Or did they quote a different rate.

I 'tested' the cell in my malfunctioning flashlight (it was a problem with the focusing ring breaking connection, only - eventually - obvious when everything electrical tested OK). Over 17A through my Fluke DVM (on 10A range) so it was a very brief test! The cell is labeled 3.7V 800mAh incidentally. Anyone who thinks that it's no problem shipping these batteries by air IMHO has been watching the Dambusters movie far too often. These bombs do not need to bounce.

Don
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Can you reread what you wrote and explain clearly what you're talking about.

The usual, accepted, manufacturers' specified, way to test battery capacity is at a current of C/10. If Rik's cells are (supposedly) rated at 5Ah, then C/10= 0.5A which is what Rik did. Absolutely 'playing safe'. And at C/10 you should get the manufacturer's rated capacity from any battery. At higher current you will get reduced capacity.

Now what is the 17A problem? Did you short circuit the cell through your Fluke? If you put a 'load' on a cell it will provide a current. Just because your load took 17A for short time, means nothing except that the cell was capable of supplying that current. Doesn't mean it was dangerous. If it is a lithium cell, it is typically rated to safely supply somewhere from 20 to 50C (manufacturer will specify) , so in your 800 mAh cell that means it should safely supply 16A minimum. (Obviously it can only supply these currents for a short time.)
 
ROSS said:
.........................and NiCad batteries are banned in the EU..
I still have about a dozen which are yonks old and think I might well get rid of ---safely..at the town dump for batteries.
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So they cant use them in cordless tools?
 
Tramcar Trev said:
Don get yourself one of these (or the generic equivalent); http://www.ebay.com.au/itm/360738305042?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_2665wt_1075
Takes all the guesswork out of the care and feeding of most rechargeable batteries, even can "rejuvenate" Nicads....
Click to expand...
Tramcar Trev said:
Don get yourself one of these (or the generic equivalent); http://www.ebay.com.au/itm/360738305042?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_2665wt_1075
Takes all the guesswork out of the care and feeding of most rechargeable batteries, even can "rejuvenate" Nicads....
Click to expand...
don9GLC said:
Just curious. How do you get a steady 0.5A discharge current? I had been thinking of an electronic load unit until I saw the prices!

And how did you time the discharge duration?
At C/10 discharge you were loading the cell at full rate (5Ah), not 'playing safe'. Or did they quote a different rate.

I 'tested' the cell in my malfunctioning flashlight (it was a problem with the focusing ring breaking connection, only - eventually - obvious when everything electrical tested OK). Over 17A through my Fluke DVM (on 10A range) so it was a very brief test! The cell is labeled 3.7V 800mAh incidentally. Anyone who thinks that it's no problem shipping these batteries by air IMHO has been watching the Dambusters movie far too often. These bombs do not need to bounce.

Don
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How did you manage to draw 17A through your Fluke Digital Multi Meter (DMM) on the 10A range without blowing the fuse or is that why the test was so short?

Any multi-meter using the ammeter function will basically connect a short circuit across a battery.

An ammeter uses a current shunt which is basically a known very low resistance (close enough to a short circuit) through which all the current flows, the voltage drop across the shunt is proportional to the current flowing through it and since its resistance is known a voltmeter (with its display scaled to display Amps) connected across the shunt is what displays the current value.
This is how the current function of a multi-meter works.

To measure the current draw from a battery a current limiting device has to be inserted into the circuit to lower the current to within the range of the meter, as an ammeter has to be connected in series for it to function.


I would seriously recommend against connecting a DMM in current mode across any battery without a current limiting device (resistor) unless you want see some interesting results (eg molten plastic lumps) or possible fireworks depending on battery chemistry.
 
Tramcar Trev said:
Don get yourself one of these (or the generic equivalent); http://www.ebay.com.au/itm/360738305042?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649#ht_2665wt_1075
Takes all the guesswork out of the care and feeding of most rechargeable batteries, even can "rejuvenate" Nicads....
Click to expand...

Thanks Trev,

I don't use Li-ions on my railway but for other portable tools, and always with the manufacturers charger.

Ive had some very good cheap electronics stuff from China on eBay and I have also had some dreadful counterfeit stuff.

If I recall correctly Apple Computer were giving away free iPhone chargers last year to protect their reputation. Cheap Chinese counterfeit chargers were catching fire. The Li-ion batteries I have seen on eBay don’t mention manufacturer or standards. If the seller is willing to be ‘creative’ with the air transport requirements I wonder just how much creativity went into the battery specification.

That's why I was interested in how closely the actual test results were to the claimed capacity. My experience with large industrial batteries from reputable manufacturers suggests that there can be a significant drop in performance particularly when commissioning takes place some time after delivery.

Don
 
gregh said:
The usual, accepted, manufacturers' specified, way to test battery capacity is at a current of C/10. If Rik's cells are (supposedly) rated at 5Ah, then C/10= 0.5A which is what Rik did. Absolutely 'playing safe'. And at C/10 you should get the manufacturer's rated capacity from any battery. At higher current you will get reduced capacity.
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Its a bit of semantics probably. 'Playing safe' to me implies less than the rated current. I'm not suggesting that it was 'unsafe' to discharge at 500mA. However, I'd be surprised if the manufacturer is known, far less a specified discharge current. I've never known a battery even from reputable Western manufacturers to perform as well in practice as claimed, and I've tested a lot of batteries. But that's a very significant reduction in capacity from the claimed 5Ah to 1.5Ah on test.


Now what is the 17A problem? Did you short circuit the cell through your Fluke? If you put a 'load' on a cell it will provide a current. Just because your load took 17A for short time, means nothing except that the cell was capable of supplying that current. Doesn't mean it was dangerous. If it is a lithium cell, it is typically rated to safely supply somewhere from 20 to 50C (manufacturer will specify) , so in your 800 mAh cell that means it should safely supply 16A minimum. (Obviously it can only supply these currents for a short time.)
Click to expand...

Then it all depends what you think is dangerous. For a single AA sized cell to be able to produce around 70W on a short is not what I would call safe. Then add another three in series to get typical G scale voltage and increase the cell capacity by 5 times. Just to make sure, squeeze the whole thing into a cramped flammable plastic container without ventilation and with a good risk of trapping a wire and causing a short. Then when it all catches fire, the cell enclosure ruptures exposing free lithium.

All I'm suggesting is that there are real dangers with such high energy densities and that extreme care is necessary. Just ask Boeing about the Dreamliner for confirmation. I have to remove the battery from my lawnmower to charge it and the charger blasts cooling air through the battery while charging. Its not from China and its definitely not 'cheap'. More like KISS prices than LGB :)

Don
 
GAP said:
How did you manage to draw 17A through your Fluke Digital Multi Meter (DMM) on the 10A range without blowing the fuse or is that why the test was so short?
. . .
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It was not a test but a 'test'. A quick and dirty way of determining if the cell had a high internal resistance. Setting up a proper test circuit would have taken quite some time for no real benefit. Yes, that's why the 'test' was short.

Provided you don't exceed the pre arcing I(squared)t for the fuse it will not operate and an industrial specification DVM such as a Fluke should cope. I would not do this on a 'hobby' multimeter. Quite right, there could be 'interesting' results!

It also helps if you have been testing large industrial batteries for many years :)

Don
 
Tramcar Trev said:
So they cant use them in cordless tools?
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I decided to have an internet search. Clear as mud, as usual. But there is a very helpful summary from Australia of the EU rules !

http://www.batteryrecycling.org.au/eu-ban-on-nicd-batteries-for-power-tools

Don
 
don9GLC said:
I decided to have an internet search. Clear as mud, as usual. But there is a very helpful summary from Australia of the EU rules !

http://www.batteryrecycling.org.au/eu-ban-on-nicd-batteries-for-power-tools

Don
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So that is why the remaining supply of Nicads are pushed of on us..... We must be the last place that allows their use....
 
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