eX-cell 3100mah Panasonic based protected 18650 cells. Highest capacity worldwide!

In testing dozen of cells with protection circuits, I've never seen a single one kick in at recommended cut-off voltage (typically 2.8v). I think I'm going to test a few cells to see how low you need to go.

There may be issue with the protection circuit cutting in, as many 3-4.2v divers have inbuilt protection

So what happens is the driver switches to protected mode @ 3v and you get something like moon mode or less .

If you want to trip the protection , you should consider a buck boost driver equipped light, so when the voltage drops the driver begins to boost and really begins to drain the battery .. This should trip the protection circuit without fail .

But this will be under load , and the voltage will begin to bounce back almost straight away , once the load is removed .

Yes, that is what I was thinking. But I would like to test if these cells do eventually cut-off at a safe point, otherwise I will have to remove my claim about running them until the PCM cuts in, which would be a shame.

The current has seriously dropped off in my T100C2 as well, it is at 0.06a now at 2.9v, I think I will go down to just below 2.5v this time to be sure. I really hate doing this to these cells though, I set aside two to keep for myself and now I am running one to within an inch of it's life.. It should be able to take it though, Panasonic say it can anyway.

Ok, I've had to call off the second test now as well, the light did go into a 'moon mode' type setting, and I gave up with the cell at 2.84v. I will try again as soon as possible but have to go test my new bike light out now before it's too late. I am going away tomorrow until Thursday afternoon so please don't worry if you can't get in contact with me until then.

I've yet to find a protection circuit that actually cut off on low voltage at low current drains. All of the ones I've seen thus far depended on boost drivers that would jack up the current to silly levels as the voltage dropped. If there is one out there that actually cuts off on voltage rather than current (for a price measured in pennies, not pounds), I'd get 100 of them tomorrow.

I have now edited the OP to reflect the possibility of bypassing the PCM at low currents, please bear this in mind when purchasing any protected li-ion cells. That said, with this being an almost universal behaviour of li-ion cell PCM circuits these cells which can be discharged to a lower 2.5v than traditional li-ion cells should offer safer performance still. As by the time they are discharged that low, and in fact even significantly before that, current will have dropped to very low levels and it will be obvious the cell needs recharging soon.

In any circuit where current won't drop obviously at such low voltages, the PCM should trip successfully, doing it's job of protecting the cell.

Im looking forward to your review Don. Thanks for taking them on for the team.

As far as I am aware (and after reading all the comprehensive battery reviews at the other place) there isnt a PCM fitted to any 18650 that will reliably disconnect power once a target voltage is reached unless combined with a substantial current draw on the battery to trip the circuit. Only one of my cheap 18650 lights (that I am aware of) is equipped with a constant current regulator (light does not dim as the cells become depleted. Amperage draw increases as voltage decreases). My early example TR-1200 with 3 x 18650's will trip the PCM once voltage drops to around 3.6V while under a heavy load. The rest of my cheap lights simply dim, and if left on, will kill a battery all the way down to 0.0V. On my examples I have noted that the heavier a CC draw is on the battery, the higher the cutoff voltage becomes.

Lets hope for cool running, mega low resistance, higher capacity numbers @ 3A than the other offerings.

I'll take 3 cells.

Shipping to Belgium please.

£27.99 for 3 cells + £3 postage = £ 30.99

I don’t mean to nitpick, but that’s constant power, not constant current. :slight_smile: Constant current would be just that… one current the entire time (like the battery discharge graphs above)

Right you are!

Only 9 left now until the next order, I'm off to the post office today to ship the first 3 sales. I'll not be back until tomorrow afternoon, (I am doing more than just going to the post office) so please don't worry if I don't reply to PMs right away.

Arrived this morning. That's the nice thing about stuff posted in the same country - it (usually) arrives very quickly.

You could get six protected trustfire flame 2400mah cells (with free shipping) for the price of one of these 3100mah cells and shipping.... Sorry, just not worth it, for me at least. It's not budget-light compatible with those prices, either...

--Bushytails

Like comparing Apples and oranges ...

I wont buy a Ferrari cos I can buy 10 Fords , and thats fair enough . But possibly un-necessary to point out .. I think it called flaming !

Wish you the best of luck RedForest , and good to see you @ BLF .

Can you? £9.99 + £2 = £11.99. Trustfire flames are £6 for two at DX, so you could get 4 surely? Believe me I have gone down that route before, the Trustfires are great cells for the money, they do pretty decent in low draw applications and some can even hold up to 2.5A. But the consistency and reliability just isn't there. I have had about 10 of them, and while 7 work fine, 3 of them have over time developed problems, and either can't sustain high currents (high resistance) or flicker on lower levels, or don't hold a voltage.

With li-ion cells I like to know exactly what I'm getting and be able to trust my cells to perform well and consistently for a long time. So I started moving further over to buying AW and Redliast cells, then I realised I could bring a higher capacity and equally high quality product to the market for less money. I know I will get comments about the price having listed on a forum dedicated to 'budget' options, they sure aren't 'budget' cells. But for their quality, they are actually priced noticably less than the competition.

Seems to be a few " based on the Panasonic 3100 cell" Li-on batteries popping up on the forums. I wonder what is happening that they are suddenly being marketed like they are the Ferraris of the battery world?

I see that the actual Panasonic 3100 is advertised for $6.55 per cell, why are the copies more expensive?

http://www.evvatech.com/sdp/1015379/4/pd-4967686/8681660.html

I went by US$, being as that's where I am - six at $8.38/pair is $25.14 with free shipping, while one of these is $22.99 including shipping... so I exaggerated slightly - you can only get five and a half protected trustfire flames for the same price, not six. So far I've had no problems with the trustfires, and with that price difference, I can throw four of them out and still have more mAh/$.

I've had problems with other brands, although I could get 14 of the ebay ultrafire 3000mah counterfeits for the same price as one of these....

And spending three times as much on a battery as the light I'd be putting in it seems just plain wrong. Even after the xm-l and new driver I plan on putting in several of my lights, these cells still cost slightly more than the lights and upgrade parts...

Find a way to sell them for under $10/cell including shipping (that's still over twice what the trustfires cost), and I'll consider testing one or two.

--Bushytails

While ~$20 does seem a bit high, it's not exactly outrageous. The price above for loose unprotected cells is for minimum 100 and the going rate for standard sanyo's on ebay is $10/apiece. Just because kinda crappy cells are $5 apiece doesn't mean someone who wants to try the latest and greatest is overspending when it's only $20 anyway.

First I'd like to point out that these aren't 'copies' they are protected cells, using the 3100mah panasonic as a 'base cell' based on does not mean a copy but that the actual foundation of the cell is the 3100mah cell. Like the $17.75 AW and Redilast 2900 cells are 'based on' the panasonic 2900 cell.

I see what you mean with mah per $, but remember all those mah aren't in one cell, and you're paying for reliability etc. I very much understand the price argument from a budget light perspective though. I mean if I only had a light worth $15 then I would not pay more for a cell for it, unless perhaps I was considering that the cell would last through a good few years of use as my light was upgraded over and over..

Unfortunately, if I sold them for under $10 a cell including shipping then I would actually be making a significant loss on each and every one. Remember I have to buy in bulk, and I also have to pay not for a bare cell but for a cell with a protection circuit made by seiko built in with good QC process and gold plated contact on the rear + extra wrapping and a button top and the sticker. I also have to pay postage myself, the price quoted on the websites you like to read isn't like at manafont and dx where they make their money for the shipping on the item cost. I have to pay significant real world shipping charges on top of that too. EDIT: I also forgot to mention import taxes of 17.5% when it comes into the UK.

Actually, when you factor in my time organising/designing this and shipping them out, after selling these 20 cells I would have been better off taking on extra overtime working in my local supermarket on minimum wage. I am just hoping when they get noticed over on CPF you will get a number of people coming over to this site just to buy these cells, and I will have a steady stream of sales, if that happens it will be worth my while to continue selling. If not, then the opportunity to buy these cells at this low price will be gone.

By the way, Don, I'm glad you got the cells so fast! How do you like them?

You only need to buy 100 to get that price = $6.55 that's $655 + shipping , unless you can pick up .

If you got 1000 Im sure you could get an even better price .

Then you could sell them in individual lots , so $655 + Shipping [ protection circuit ? + wrapped in your own label = hmmm wonder what that costs ] and then lets not forget something for your trouble , and the final price = ?

Sorry guys , you dont get something for nothing : and the few Jap cells I have , are better than the Chinese ones .

Im not forcing anything on anyone , but seriously , it takes a fair bit of Gumption to go out and make something happen , and I really dont see why the need to flame , if your not interested thats fine , but why this ?

This is no different than getting flamed over at the other site for mentioning budget lights !

I am surprised at the "flaming" that occurs in for sale threads at CPF. I am a member of other forums (not flashlight/knives) where comments in for sale threads that are not related to buying the item are not tolerated. I would not like to see that kind of heavy moderation here but as old4570 says if your not interested , don't comment.