A few questions about 14500 Li-Ion cells.

[ifoxbox]

I was wondering if someone has done a comparison on 14500 cells like SilverFox has done for other size Li-Ion cells? I read over the shootout that SilverFox has done in the sticky, but could not find any 14500 reviews.

I was curious about the capacity of the 900Mah Ultrafire cells (blue / grey) compared to the flat top Tenergy 800Mah cells that Batteryjunction has.

What is the highest known capacity for a flat top 14500 cell. All I can find is 800Mah.

Last question; does anyone know where I can find more info on a Sony flat top 14500 Li-Ion cell. It is green and the # on the sticker is:

06133320812951198

I am curious if the cell is protected or not. I searched on google, but could not find a single 14500 cell from sony. I am putting in the wrong key words. :duh2:

Thanks in advance for your help!

 

[Hitthespot]

I'm not sure if there has been a comparison review done on 14500 cells.

You must be carefull with Lithium (4.2V) batteries. Sony may carry a type, and I heard that panasonic had one available. Then there are the Saft batteries. However most of those outside of what is discussed on CPF will not take the high current drain required by modern LED flashlights. Now you never stated Flashlight applications was why you were interested in the Sony 14500 cells, just be aware of the current issue and make sure you have the specs before deciding a battery is correct for an application. Not to mention the protected vs non-protected 14500 batteries. Not all 14500, RCR123's etc... are created equal.

Most here have had very good results with AW batteries for flashlight use.

Hope this helps



Bill

 

[ifoxbox]

Hi Bill,

Thanks for your reply! The application is actually for an electric toothbrush. It has a Sony Li-Ion in it with the number I listed in my first post. I wanted to find out more about that cell so I could know the best way to proceed with finding a replacement.

I don't know the charge rate of the charger, but I know it must be low. The manual says that it takes 24 hours for it to receive a full charge. It also says that it can be kept on the charger indefinitely. With this info in mind, is there a specific brand that would do better than another? I found a couple of TrustFire (Grey) and UltraFire (Blue) 14500 cells for a good deal, but wanted to find out the specs of the Sony before buying anything.

Do you know what the highest Mah rating is for a 14500 cell is? Both flat and button top?

Thanks!

 

[marschw]

If it recharges, it's not the Saft one (that's Lithium Thionyl Chloride), and thus discharge rate won't be an issue.

 

[LuxLuthor]

Hi Bill,

Thanks for your reply! The application is actually for an electric toothbrush. It has a Sony Li-Ion in it with the number I listed in my first post. I wanted to find out more about that cell so I could know the best way to proceed with finding a replacement.

I don't know the charge rate of the charger, but I know it must be low. The manual says that it takes 24 hours for it to receive a full charge. It also says that it can be kept on the charger indefinitely. With this info in mind, is there a specific brand that would do better than another? I found a couple of TrustFire (Grey) and UltraFire (Blue) 14500 cells for a good deal, but wanted to find out the specs of the Sony before buying anything.

Do you know what the highest Mah rating is for a 14500 cell is? Both flat and button top?

Thanks!

Silverfox may know of others, but the highest I have ever seen in that size is 800mAh. I don't think in a low output/recharge scenario like a toothbrush that you would notice any difference looking for the slightly higher mAh in between brushes. I think quality branding is more important, and I'm personally not a big fan of Trust/Ultra Fire.

If it only uses a single cell, I would personally use one of AW's protected brand since I would be holding it and shoving it in my mouth. Most commercial uses of Li-Ion use cells that are contact welded to a protection circuit, so that's another consideration on safely reattaching leads if not a drop in.

 

[ifoxbox]

Thank you for the reply!

Would the protection circuit you are talking about be visible on the cell. I do not see anything on the Sony that was in there. Don't you think that the toothbrush handle's PC board would have a protection circuit to monitor the cell? This handle and charger was built specifically for a Li-ion 14500 cell. I would imagine that they would make it as safe as possible. IF that was the case, would it not be safe to go with a different brand cell?


I would really like to get more info on the Sony battery, but I can not find anything. Does anyone know where I can get specs on any Sony 14500 Li-ion?

 

[LuxLuthor]

Thank you for the reply!

Would the protection circuit you are talking about be visible on the cell. I do not see anything on the Sony that was in there. Don't you think that the toothbrush handle's PC board would have a protection circuit to monitor the cell? This handle and charger was built specifically for a Li-ion 14500 cell. I would imagine that they would make it as safe as possible. IF that was the case, would it not be safe to go with a different brand cell?


I would really like to get more info on the Sony battery, but I can not find anything. Does anyone know where I can get specs on any Sony 14500 Li-ion?

The main question is if they built the battery holder with a slot/holder that allows the cell to be freely removed, vs. having the remove welded connections to the end of the cell. They can put the protection circuit inside the toothbrush, but typically they are attached with welded contact strips to the ends of the cell. Most commercial use of Lithium Ion cells don't have the same swap out battery holders like you might find in a radio or CD playing,. It's not easy finding details on some brands such as Sony, because they ONLY intend on selling them directly to manufacturers who are agreeing to use them with protection circuits. They don't intend on selling them to the consumers like the do with NiMH cells.

 

[mdocod]

I think you would be better off concerning yourself far less with the label capacity of the cell, and far more with the build quality, safety, and longevity of the cell... The problem with numbers, is that people gravitative towards them when we don't have any other useful parameters to use as a comparison. A larger number must be better right? As it would just so happen, this is almost never the case, but all too many industries would like for you to believe that a larger number is better.

If you are brushing your teeth long enough to wear down the cell in one sitting, then you are probably drinking blood all night. If the cell is going dead in the time it takes to brush your teeth (normal, like 2 minutes or something like that), then it should be replaced as it is no longer suitable for use and is posing a safety risk.

Ideally speaking, one would find a quality name brand cell from Sony, Panasonic, Samsung, Sanyo, Molicel, LG etc... Seems that name brand loose li-ion cells have pretty much dried up as far as availability in the last few years. Picking up an AW brand 14500 will guarantee you are getting a decent quality chinese cell that should work just fine. If you want to go "all-out" and try to find a name brand cell, I have a hunch that the RCR-V3 packs from Kodak probably contain a pair of name brand 3.7V 14500s, but this is only speculation.

There is a 99.727% chance that the cell in your toothbrush is externally protected by the electronics in the toothbrush. The PCB would be identifiable as a raised "strip" along the side of the cell possibly in conjunction with a tail end that does not look to be made of the same metal as the positive end of the cell...

 

[ifoxbox]

There is nothing beside the cell. The cell is soldered in to the handles PCB. Since I believe that the cell is being monitored by the handles PC board, what are the dangers of going with an off brand cell? Wouldn't you think that the handles PCB would do the same as any other cell?

I am not looking for just the highest mAh labeled cell. I do want the handle to last as long as it did before, since I travel a lot and not having to bring the charger is a plus. I was just curious what the highest labeled cell was. I do understand that many of the off brand cells do not live up to there printed capacity. That is why I was asking if anyone had done a shootout like SilverFox for 14500 cells.

Thanks for your input.

 

[Hitthespot]

If it only uses a single cell, I would personally use one of AW's protected brand since I would be holding it and shoving it in my mouth.

After what we've seen here, Amen to that brother!

Bill

 

[mdocod]

How about a little fear-mongering....

Lithium cobalt produces it's own oxygen during a burn. It can be a very dangerous metal fire that is difficult to extinguish, all while producing toxic off-gassing. Poorly manufactured cells are likely to have an increase in impurities that could lead to microscopic internal shorting that increases the likelihood of a thermal runaway condition. It seems that many off-brand cells, especially tenergy and ultrafire (as of late) are reported as having wildly varying cell-to-cell consistency, which is a very strong indicator of poor quality control in manufacturing, or possibly the use of factory rejects or heavily aged cells with a new shrink-wrap slapped on em.

PCBs can't protect from poor build quality or cell defects.

 

[Linger]

Caution - Is the cell 1.2v (or 1.5v) OR is it 3.7v?

Can you check the old cell with a multi-meter?
All the electric tooth brushes i've seen have had 1.5v cells in the handles. It could be lithium and still 1.5v (I've picked these up from dx).

(Even an alkaline AA battery serves a long time in a tooth brush. I've had aaa alkaline batteries in a brush (bundle from costco, not my idea) that performed well.)

 

[ifoxbox]

Caution - Is the cell 1.2v (or 1.5v) OR is it 3.7v?

It is a 3.7v cell.

It seems that many off-brand cells, especially tenergy and ultrafire (as of late) are reported as having wildly varying cell-to-cell consistency, which is a very strong indicator of poor quality control in manufacturing, or possibly the use of factory rejects or heavily aged cells with a new shrink-wrap slapped on em.

PCBs can't protect from poor build quality or cell defects.

Have there been many reports of those brand batteries experiencing thermal runaway? It does not make sense that companies are able to sell these poorly manufactured cells if they are a safety hazard. Besides AW brand, are there any other decent brands of Li-ion available to purchase?

Thanks again for your thoughts!

 

[Hitthespot]

It is a 3.7v cell.
Besides AW brand, are there any other decent brands of Li-ion available to purchase?

Thanks again for your thoughts!

I do have one of the Ultrafire gray 14500 protected cells that I use with my Nitecore Defender Infinity. It is listed at 900 mah and I have not had any trouble with it in over a year of hard use. I also have (2) AW 14500's and rotate continuously between the three cells. I believe the AW 14500 cells are listed at 750 mah IIRC, but they last just as long in my experience.

Hope this helps.

Bill

 

[ifoxbox]

Thanks for the info Bill!

 

[mdocod]

It is a 3.7v cell.


Have there been many reports of those brand batteries experiencing thermal runaway? It does not make sense that companies are able to sell these poorly manufactured cells if they are a safety hazard. Besides AW brand, are there any other decent brands of Li-ion available to purchase?

Thanks again for your thoughts!

Most lithium battery explosions reported here are actually of lithium manganese dioxide primary cells (CR123s). With the majority of reported incidents occurring with chinese made CR123s. I do vividly remember a report involving a multi-RCR123 LiCo powered light using ultrafire brand cells that had a battery explosion. I haven't seen much else along the lines of LiCo explosions here on the forum and they are quite rare. When I said above that I was "fear mongering" that was indeed a proper point to make considering the very few li-ion explosions, regardless of make, that are reported here. When I know there is potential danger, i always like to point out that fact and steer people in a direction that I feel will minimize that risk. Other cell chemistries just aren't as potentially dangerous, so quality really just translates to cycle life, consistency, performance and capacity, with LiCo or Lithium primary, I think it's important that awareness is made of the potential danger.

-Eric

 

[Hitthespot]

Your words and others in this thread should be read with great care Eric. While I did state I have used an Ultrafire 14500 without incident for over a year, I believe that most of the problem cells we read about around here are Ultrafire or Trustfire.

I would like to clarify for the OP that I was just stating I personally have not had problems with AW or my Ultrafire. However, these kinds of Lithium cells are obviously more dangerous than any other consumer battery type, I am no expert, and I am in no position to recommend or advocate the use of Ultrafire, Trustfire, or even AW for that matter.

In other words if you don't know what your doing I would leave these batteries alone. Buy a new tooth brush.

Bill

 

[DM51]

Members would do well to heed the words of mdocod and Hitthespot on this subject. It is not difficult at all to get it right when dealing with Li-Ion (LiCo) cells, but at the same it is foolish not to take care with them.

This is a post I made about 18 months ago, but I think it is worth repeating:

If you:

~ Buy good quality protected Li-Ion cells
~ Use a good quality charger
~ Don't charge them at >1C
~ Don't charge them to >4.2V
~ Attend to the charge, watching out for any sign of overheating
~ Don't discharge them at >2C (runtime should be >30 mins)
~ Don't discharge them to <3.5V resting (or <3.0V under load)
~ Make sure they are balanced with other cells when used in multi-cell applications
~ Inspect them regularly for any sign of damage, dents, discoloration etc
~ Recycle them when they can no longer hold ~80% of charge (4.0V)

Then you will not have a problem with them.

 

[mdocod]

Found another one (this is not the same LiCo explosion I was referring to before)
http://www.candlepowerforums.com/vb/showthread.php?t=186165

 

[ifoxbox]

Thanks for all the input. I will give serious consideration to all that was mentioned before deciding on a replacement.

Thanks again!