# NITECORE Power – The D4 and D2 Digi chargers and NITECORE's li-ion cells



## subwoofer (Aug 26, 2014)

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Author's Statement for Transparency and Disclosure
The test sample/s featured in this article were provided for technical testing and review by "NITECORE". Test samples are retained by the reviewer following publication of the completed review for the purposes of long term testing and product comparisons.
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NITECORE were one of the first (if not the first) manufacturers to offer a serious automatic multi-chemistry battery charger with their release of the i4. Early teething problems were sorted with the i4 V2, and building on this early experience, NITECORE have just released two new 'smart' multi-chemistry chargers, each with a full informative display, the Digi charger D4 and D2.








NITECORE also offer a range of top specification li-ion cells (but no NiMh option at this time). You can go with a single brand solution, with light, cells and charger all being NITECORE, or mix and match any of these components with other manufacturers products.







This review is intended to show these products and how they work from a user's perspective with key observations but not including detailed technical analysis.


_Author's note: due to the general tendency for reviews to become ever longer, this review is presented in a different format to my previous ones, with all but a few images being animated to attempt to reduce excessive scrolling. You may need to wait for the images to load fully._



Taking a more detailed look:

Starting with the smaller of the two Digi chargers, the D2.

The photos here show; the packaging, contents, the banner label and screen's protective films being removed, the pristine D2, the screen when powered on but no cells are inserted, a single 18650 showing the voltage, then charging current, adding a second li-ion cell shows its voltage, the finished charging voltage displayed for a NiMh cell (also showing the LOW charge current setting), and the display when all cells being charged have completed.







A quick look round all sides of the D2.







Now moving onto the larger of the two Digi chargers, the D4.

The photos here show; the packaging, contents, the banner label and screen's protective films being removed, the pristine D4, the screen when powered on but no cells are inserted, a mixture of cell sizes and types showing the voltage, then charging current, using only two bays gives the maximum 750mA charge current, inserting a NiMh cell in the wrong way round shows the 'Err' error condition, the finished charging voltage displayed for a li-ion cell, the manually selectable LiFePO4 charging mode, and the display when all cells being charged have completed.








A quick look round all sides of the D4.







The new Digi chargers are slightly bulkier and heavier than the earlier Intellichargers. The D4 and D2 are shown here with an i4








Modes, Features and User Interface:

Both the D4 and D2 operate in exactly the same way, with the only differences being the number of bays and charging currents, so for the purposes of this section I will discuss the D4. Rather than simply repeat everything in the user manuals, I will stick to the salient points. For a look at the full user manuals, you can find them on NITECORE's website:

NITECORE D4 User Manual - NITECORE D2 User Manual

Firstly, the D4 and D2 support a vast array of cells which include:

Li-ion (including IMR) - 26650, 22650, 18650, 17670, 18490, 17500, 18350, 16340(RCR123), 14500 and 10440
Ni-MH and Ni-Cd - AA, AAA, AAAA and C
3V Li-ion / LiFePO4 – (in whichever of these sizes you can find) 26650, 22650, 18650, 17670, 18490, 17500, 18350, 16340(RCR123), 14500 and 10440

Of all of these, the only cells requiring any user intervention are LiFePO4 (all sizes), AAAs (if less than 4 are being charged), 10440s, and some 16430s.

All of the other cell types and sizes can simply be slotted straight in and charge perfectly in any combination.

These chargers have a very simply two button interface with a 'SLOT' button for selecting which bay the display shows detailed information for, and 'MODE' for cycling the display detail and activating a couple of special modes.


For the 'special' cells that need user intervention, it is simply a matter of selecting the LiFePO4 charging mode, or the 'Low' charge current for each bay when you load the cell.

LiFePO4 charging is selected once the cell is inserted by pressing and holding the 'MODE' button for more than 2s immediately after the initial check has completed. LiFePO4 will be shown on the display for that bay to confirm this mode has been selected.

'Low' charging current can be selected at any time, by first choosing the bay with the 'SLOT' button and then holding the 'MODE' button for more than 1s. 'Low' will be shown on the display to confirm this low charging current has been selected. This will use half the maximum charging current (so 375mA in the D4 and 300mA in the D2).


Both units display voltage and current readings. The voltmeter has a maximum reading of 4.20V, and will not display a higher voltage even if a cell slightly over this voltage is inserted. In practice, though I would prefer not to have this limit for peace of mind, but as the Digi chargers terminate li-ion cells at exactly 4.20V, as long as the cell is charged on the D4 or D2, this will show the real cell voltage. In all examples of testing, the reading on the D4 and D2 exactly matched four voltmeters I have to 0.01V.

I've not confirmed the current readings displayed, but have observed the charging current reducing once the charger enters the CV phase of the charging algorithm.

As well as the charging current and cell voltage, the total charging time is also shown and during normal charging these cycle through one after the other.

Both displays are backlit making them easy to see in daylight and quite bright when the room is dark. NITECORE have included the option to switch off the backlight, and this is done by simply pressing and holding the 'SLOT' button at any time for over 1s. Repeating this procedure switches the backlight back on. When the backlight is off, the LCD display is still visible and you can read the values using ambient light.

To get the maximum charging current with the D4 you need to use bay 1 only with bays 2 or 3, and NOT bay 4. The D4 will halve the charging current if you use bays 1 & 4 together, or 2 & 3. NITECORE say this is a design feature relating to charging larger size cells (however I'm not sure I agree).


When inserting a cell, the D4 and D2 carry out a brief cell type and condition test. If this fails for any reason, 'Err' is shown in the display which tells you to remove the cell as soon as you can.

For more details, please see the links at the start of this section for the full instruction manuals.








Wrapping-up

Since the D4 and D2 arrived, I have used them exclusively for all of my 'considerable' charging requirements. Though not the fastest chargers, so far, they have performed flawlessly. Li-ions come off the charger at exactly 4.20V (depending on the cell age, after resting this might drop off slightly), and NiMh cells at the same voltage my dedicated NiMh chargers give (between 1.47V and 1.54V depending on the exact cell used).

The ability to safely charge single smaller cells is also a boon. I have little use for 10440, but do want to charge a single cell from time to time, and likewise don't always want to charge AAAs at 750mA, so being able to drop to 375mA or 250mA is very useful.

If plugged in, but no cells are inserted, the D4 and D2 also go into an ECO mode, switching off the display and entering a standby mode to save power.

The contact sliders are amongst the smoothest I've found on any charger, but despite this I still prefer to adjust them as much as possible by hand first and then pop the cell into place.

Both units have a 12V socket to use with a car charger adapter. It is a pity NITECORE does not include one with the charger, instead you need to buy it as an accessory. However the socket is a pretty standard size so, like me, you might already have a suitable car adapter (such as the one from the i4).


NITECORE's selection of li-ion cells covers most of your needs. All of them are my preferred cell design, having button tops. Using button tops makes them more universally compatible with different lights. Many lights have built-in physical reverse polarity protection, this protection makes the use of flat top cells impossible.

Though not specifically run through capacity tests, all of the NITECORE cells have performed in accordance with their state capacity in comparative real world use.

The D4 and D2 make it a little difficult to say much more as they….. just….. work.

So in a He-Man stylee , 'By the power of NITECORE, I have the POWER!'






If you enjoyed the review, please remember to 'Like' me on Facebook






Important update - 26650 Users take note!

The D2 comfortably takes 2x 26650, however, the D4 does not. In the D4 a single 26650 sits very comfortably in either slot 2 or 3, however you cannot fit a 26650 into both slot 2 and 3 at the same time. Slots 1 and 4 in the D4 just about take a 26650, but the cell can easily pop off the positive contact pad and stop charging.


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## subwoofer (Aug 26, 2014)

Reserved for updates...

Important update - 26650 Users take note!

The D2 comfortably takes 2x 26650, however, the D4 does not. In the D4 a single 26650 sits very comfortably in either slot 2 or 3, however you cannot fit a 26650 into both slot 2 and 3 at the same time. Slots 1 and 4 in the D4 just about take a 26650, but the cell can easily pop off the positive contact pad and stop charging.

Update 18 Nov 2014:
Finally some LiFePO4 cells I ordered have arrived so I could try out the LiFePO4 charging.
All four cells terminated at 3.7V and the display held this voltage stead post termination. After 24 hours rest, all four cells are at 3.35V. If anything changes after further use I'll post an update.


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## Javora (Aug 26, 2014)

Thanks Subwoofer, this is the review I was waiting for.


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## gunga (Aug 26, 2014)

Great review! I just got my D2 a couple days ago!


Sent from my iPhone using Candlepowerforums


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## subwoofer (Aug 30, 2014)

Post 2 updated.


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## glevum (Aug 30, 2014)

Just got a D4 after your review on BritishBlades. Very happy. Thanks


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## Milo Fisher (Sep 1, 2014)

I have a D2 and was interested in the trickle issue raised in HKJ's excellent review of the i4 charger at http://www.candlepowerforums.com/vb...ew-of-Charger-NiteCore-Intellicharger-i4-2014. I charged up a partially discharged 1600 mAh Panasonic NiMH battery and was pleased to see the 500 mA output was exactly that as measured on my multimeter.






After it finished charging, there was no trickle current (compared to 100 mA as measured by HKJ).






I am pleased to see that they have removed the trickle charge feature and am very happy with the D2 charger.


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## pilou (Sep 1, 2014)

A couple of comments on the great review:

- Just a minor correction: the low current mode on the D2 runs at 300mA, not 250mA (at least on mine).
- A number of vendors are bundling the car charger cable in very cost effective packages.

I have so far charged two 18650s and a bunch of AA Eneloops. The Eneloops actually charge faster and with less heat than the simple charger Sanyo bundles with their multi-battery packs. Being able to charge LifePO4 batteries is a great feature since a I am planning on getting a few of them for my single CR123 cell lights.

*D2 vs D4*: When I ordered my D2 a couple of weeks ago, the nearly double cost of the D4 did not make sense to me. Sure, you get higher charging current capacity, but not when charging four batteries at the same time, in which case you actually end up with lower charging current. So for people whose main priority is to charge many batteries as quickly as possible, buying two D2s instead of a D4 would have made more sense. Also, the spacing between the bays is much more generous on the D2, making it a lot easier to remove batteries.

But I now see that you can get a D4 bundle for $US28 compared to $20 for the D2. The price difference now makes a lot more sense. At those prices they are both good values.


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## twin63 (Sep 1, 2014)

Very informative review. Thanks for posting it. I am new to rechargeables. I purchased a D4 and have used it so far to charge Eneloops, a couple of 18650's, and a couple of 14500's. I have a question, though. I just bought a used Quark Pro QP2L-x. I will be running the KeepPower 16650 in this light. It's not listed as a cell that the D4 is compatible with. Will I need to buy a new charger for the 16650 cells, or will I be able to charge it on the D4? I will email tech support at Nitecore, but just wondered if anyone has already dealt with this.


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## UnderPar (Sep 1, 2014)

twin63 said:


> Very informative review. Thanks for posting it. I am new to rechargeables. I purchased a D4 and have used it so far to charge Eneloops, a couple of 18650's, and a couple of 14500's. I have a question, though. I just bought a used Quark Pro QP2L-x. I will be running the KeepPower 16650 in this light. It's not listed as a cell that the D4 is compatible with. *Will I need to buy a new charger for the 16650 cells, or will I be able to charge it on the D4? I* will email tech support at Nitecore, but just wondered if anyone has already dealt with this.



No need. I also have the same question before. But the answer is yes, it can charge your 16650.


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## HKJ (Sep 1, 2014)

twin63 said:


> Very informative review. Thanks for posting it. I am new to rechargeables. I purchased a D4 and have used it so far to charge Eneloops, a couple of 18650's, and a couple of 14500's. I have a question, though. I just bought a used Quark Pro QP2L-x. I will be running the KeepPower 16650 in this light. It's not listed as a cell that the D4 is compatible with. Will I need to buy a new charger for the 16650 cells, or will I be able to charge it on the D4? I will email tech support at Nitecore, but just wondered if anyone has already dealt with this.



There is no problem charging the Keeppower 16650 in the D4. 
Generally chargers do never list all the LiIon sizes they support, there are simply to many sizes. Just with the xx650 cell you have: 26650, 18650, 17650, 16650, 14650.


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## twin63 (Sep 1, 2014)

UnderPar & HKJ - That's good news...thanks!


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## pilou (Sep 2, 2014)

twin63 said:


> I will be running the KeepPower 16650 in this light. It's not listed as a cell that the D4 is compatible with. Will I need to buy a new charger for the 16650 cells, or will I be able to charge it on the D4? I will email tech support at Nitecore, but just wondered if anyone has already dealt with this.


Yes, but with a small caveat. A 16650 is supposed to be charged to 4.3V to reach full capacity. But based on some tests (posted on this site among others), they will reach 95+% of full capacity on a regular 4.2V Li-ion chargers, which is good enough for me.


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## HKJ (Sep 2, 2014)

pilou said:


> Yes, but with a small caveat. A 16650 is supposed to be charged to 4.3V to reach full capacity. But based on some tests (posted on this site among others), they will reach 95+% of full capacity on a regular 4.2V Li-ion chargers, which is good enough for me.



And on the Keeppower the protection prevents charging to 4.3V, making a 4.2V charger perfect for the Keeppower 16650.


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## subwoofer (Sep 3, 2014)

pilou said:


> A couple of comments on the great review:
> 
> - Just a minor correction: the low current mode on the D2 runs at 300mA, not 250mA (at least on mine).
> - A number of vendors are bundling the car charger cable in very cost effective packages.
> ...



Thanks for your comments, and the correction (missed this due to not getting my normal thread update emails). Yes, of course the LOW on the D2 is 300mA (main review corrected now). I had also added a comment about the bay size and 26650 cell charging. In some ways I would prefer a 4 bay D2 the size of two D2s stuck together.


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## mwb01 (Sep 3, 2014)

> 3V Li-ion / LiFePO4 – (in whichever of these sizes you can find) 26650, 22650, 18650, 17670, 18490, 17500, 18350, 16340(RCR123), 14500 and 10440



Thanks for the review!

I'm considering buying the D2 so I can get rid of my gazillion different chargers, and was wondering if the above quotation means it can charge these 3v Li-Ion batteries. I'm guessing they use some kind of circuit to force a regular 3.7v cell down to 3v, since Tenergy says they should only be charged with their special charger. Do you know if the D2 could charge them safely and effectively?

Thanks


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## subwoofer (Sep 5, 2014)

mwb01 said:


> Thanks for the review!
> 
> I'm considering buying the D2 so I can get rid of my gazillion different chargers, and was wondering if the above quotation means it can charge these 3v Li-Ion batteries. I'm guessing they use some kind of circuit to force a regular 3.7v cell down to 3v, since Tenergy says they should only be charged with their special charger. Do you know if the D2 could charge them safely and effectively?
> 
> Thanks



The method used by Tenergy is different to the LiFePO4 chemistry in that (I think) they use a PCB to give 3V output characteristics from a standard 4.2V cell. These cells typically need the cell inside to be charged to 4.2V or they don't store the energy they should. I would suspect that these should be charged as normal li-ions making the LiFePO4 charge mode of the D2 and D4 irrelevant. However, and it is a big HOWEVER, I do not have any of these cells, nor the full understanding of how they work and what can be done safely with them. HKJ might have a better idea than I do, so my advice is to not go jumping in to this without further investigation.


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## pilou (Sep 6, 2014)

subwoofer said:


> The method used by Tenergy is different to the LiFePO4 chemistry in that (I think) they use a PCB to give 3V output characteristics from a standard 4.2V cell. These cells typically need the cell inside to be charged to 4.2V or they don't store the energy they should. I would suspect that these should be charged as normal li-ions making the LiFePO4 charge mode of the D2 and D4 irrelevant. However, and it is a big HOWEVER, I do not have any of these cells, nor the full understanding of how they work and what can be done safely with them. HKJ might have a better idea than I do, so my advice is to not go jumping in to this without further investigation.



There are two types of rechargeable Tenergy RCR123s on the market: the one you just described, which is blue and is (over?)rated at 900mAh, and then there is an actual LifePO4 Tenergy that is green and rated at 750mAh. I just bought a few of the green ones and charged them on the D2 on the LifePO4 setting. The terminal charging voltage was 3.70V. The LifePO4s retain their voltage better and therefore probably deliver as much or perhaps even more energy than the 900mAh LI-ion with PCB voltage regulation. In addition, they don't come with the warning of the 900mAh, "Initial cell voltage of 3.6V switches to 3-3.2V within 12ms", they cost 30% less, and they will likely last longer. It's a no-brainer in my view. I have already tried them in a 1-cell Inova T1 and a two-cell X5. At $3 a pop, you can't go wrong with them.

PS: it started with const current and then switched to const voltage near the end with trickling current.


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## subwoofer (Nov 18, 2014)

Update 18 Nov 2014:
Finally some LiFePO4 cells I ordered have arrived so I could try out the LiFePO4 charging.
All four cells terminated at 3.7V and the display held this voltage stead post termination. After 24 hours rest, all four cells are at 3.35V. If anything changes after further use I'll post an update.


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## Mr. Nobody (Jan 22, 2015)

DeLeTeD


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## Rick NJ (Jun 7, 2015)

Hi folks,

I am considering the D2. My 18650 cells are a bit on the long side. From tip of the button to the base is 71.2 mm to 71.5mm.

I have looked up and down and I found inconsistent comments. One "buyer review" said 70mm, another said 68mm. Can anyone with a D2 measure what is the max cell length that I can squeeze in?

If max is 72mm, life is good. If it is 70mm, I could repack my savaged laptop cells possibly down to 70mm by removing one of the two 0.3mm insulation layer I put in. But I don't think I could get it down to 68mm.

Thanks!
Rick


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## RI Chevy (Jun 7, 2015)

Welcome to the Forum! :welcome:

If fellow member HKJ did a review of this charger then read the top part of the review and he will let you know if the cells will fit or not. His reviews are extremely thorough and informative.

http://www.lygte-info.dk/info/indexBatteriesAndChargers UK.html

I do not want to take anything away from this review by subwoofer. This was also an excellent review. :thumbsup:


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## Rick NJ (Jun 7, 2015)

RI Chevy said:


> Welcome to the Forum! :welcome:
> 
> If fellow member HKJ did a review of this charger then read the top part of the review and he will let you know if the cells will fit or not. His reviews are extremely thorough and informative.
> 
> ...



Ah, I did not see see those posts! Thanks for pointing it out.

Too bad, HKJ's review has max battery length at 69.3mm long. Darn. That would mean I need to repack all my 18650 to use this charger!

All my 18650 is 71-72mm long. (extra insulation, thick wire...)

I have been using a cheap charger board and it works adequately well, but the web of gator clips to connect it up makes it "my use only". I was hoping this could be for my family's use so they can charge the 18650 themselves.

May be I will repack those old laptop batteries to make it just a bit shorter, but I really like the extra insulation I have... Darn, this would have been good had max be 72mm.

Thanks just the same RI Chevy! (and thanks HKJ for the review). While it is not the answer I like, but at least now I know.

Rick


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## RI Chevy (Jun 8, 2015)

Read through some of his other reviews and see if there is a charger that may accept the 72mm length. There may be some other options out there for you.


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## subwoofer (Jun 8, 2015)

Just to add to HKJ's excellent information, I've just measured both bays in my D2 and they were 69.6mm and 69.9mm.


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## Rick NJ (Jun 8, 2015)

subwoofer said:


> Just to add to HKJ's excellent information, I've just measured both bays in my D2 and they were 69.6mm and 69.9mm.



That is encouraging...

After reading RI Chevy's reply, I was about to give up, stick with my charger boards until I find another charger; or figure out a way to "package" my charger board with a good UI for family so they don't have to fiddle with gator clips.

My extra long 18650 is because I have been liberal with insulation.

I did some calculation, even if I repack my 18650, I still can't squeeze it down to 69.3mm, but 69.9mm is a possibility.
Top side: Flat top cover 1.5mm + insulation 0.3mm + wire 0.7mm = 2.5mm
Bottom side: protection board 1.7mm + insulation 0.3mm + wire 0.7mm = 2.7mm
Total = 5.2mm added, plus 65mm for the cell, that is 70.2mm.

That is just 0.3mm over the 69.9mm. I know I can strip the cell's factory shrink cover and get 0.3mm, but I prefer to leave that on. If I can somehow do the bottom side wiring within the protection board's vertical space, that would work. Going with minimal insulation really makes me nervous but it could work.

I already ordered some of the thin 1.5mm top-cover. I am going to repack one of my 18650 and see if I can indeed squeeze it to <=69.9mm, and also see if I feel comfortable with taking out my extra insulation.

Hey, THANKS RI Chevy & Subwoofer! Without your help, my only solution would be to cross my finger, order the darn thing and hope for the best; and sometimes, the best doesn't work out. So thanks for the trouble and info. Now I know what I am getting into.

With thanks,
Rick


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## HKJ (Jun 8, 2015)

You could also get a charger that could handle long cells, some of them are:

http://lygte-info.dk/review/Review Charger Xtar VC4 UK.html
http://lygte-info.dk/review/Review Charger Opus BT-C1000 UK.html
http://lygte-info.dk/review/Review Charger Opus BT-C3100 V2.1 UK.html


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## RI Chevy (Jun 8, 2015)

Thank you Henrik. :thumbsup:
Options. We always have options. 
Much better than messing with all the cells. Just get a charger that fits your needs.


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## Rick NJ (Jun 8, 2015)

HKJ said:


> You could also get a charger that could handle long cells, some of them are:
> 
> http://lygte-info.dk/review/Review Charger Xtar VC4 UK.html
> http://lygte-info.dk/review/Review Charger Opus BT-C1000 UK.html
> http://lygte-info.dk/review/Review Charger Opus BT-C3100 V2.1 UK.html





RI Chevy said:


> Thank you Henrik. :thumbsup:
> Options. We always have options.
> Much better than messing with all the cells. Just get a charger that fits your needs.



Indeed, HKJ! Much THANKS for those links and the hard work in doing the review. Very informative. I begun considering Nitecore because of its low cost - it is not much more than what I would need to spend on parts if I am to "repackage" my charger boards into something more user friendly for family to use. Some of this chargers are so feature rich it makes them very tempting even though they are 2x-3x the price of Nitecore D2.

I will look at the links reviews carefully and see if I want to spring for one of them - quick looks is, very attractive, but I will look closer.

Back to length for a moment:

I must not be alone with this problem with salvaged laptop batteries. I suppose most of the manufacturers are targeting non-fiddling consumers using manufactured batteries instead of salvaged batteries. However, this really puzzle me some. The 18650 users are different from users of AAA or AA batteries. I would guess (without any supporting data) that for the 18650 users including the e-cig folks, "salvagers" like myself could be a larger share of the the user base comparing to "manufactured-battery" users.


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## Rick NJ (Jun 8, 2015)

Thanks for all your input, RI Chevy, Subwoofer, and in particular, HKJ for your detail reviews.

I've looked all HKJ's review pointed out by RI Chevy and some from web search. Right now, I am leaning towards the BT-C3400. From various sources, the BT-C3400 is the BT-C3100 with newer firmware. And thanks to HKJ's review, the BT-C3100 takes battery from 32mm to 72.5mm and has over-temperature shut down.
http://www.candlepowerforums.com/vb/showthread.php?389732-Test-Review-of-Charger-Opus-BT-C3100-V2-1

I am expecting the max length didn't get shortened when it was rebranded BT-C3400. I emailed the eBay seller and ask if he could check -- same seller whom I purchased my LaCross BC700 NiMH charger 1-2 years ago, and some of my Eneloop supply also came from this gentleman. I hope he can check and came back telling me 72mm battery is no problem.

The BT-C3100 will accomplish the "user-friendly" aspect for my family. They have been using the BC700 for the NiMH for over a year. It has almost the exact interface as the BT-C3400. The "REFRESH", "CHARGE-TEST"... options are familiar ones. Some minor differences in the way the options work, but by-and-large the same. I don't even have to "retrain" them or myself.

I am eagerly waiting the seller's reply. I see no reason why the max battery length would reduce from BTC3100 to BT-C3400. I probably wont order right the way but chew on it a bit to avoid buyer's remorse.

What do you think? Good choice?

With thanks,

Rick


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## Rick NJ (Jun 9, 2015)

Rick NJ said:


> Thanks for all your input, RI Chevy, Subwoofer, and in particular, HKJ for your detail reviews.
> 
> ...
> The BT-C3100 will accomplish the "user-friendly" aspect for my family. They have been using the BC700 for the NiMH for over a year. It has almost the exact interface as the BT-C3400. The "REFRESH", "CHARGE-TEST"... options are familiar ones. Some minor differences in the way the options work, but by-and-large the same. I don't even have to "retrain" them or myself.
> ...



Oh, well... My impatience got the better of me. I was going to wait a bit to avoid buyer's remorse. The eBay seller RDANA replied to my question and he measured the BT C3400 max battery length at 71.4mm. 71+ is a green light for me. I got my LaCross BC700 from him a couple of years back, and some of my NiMH-LSD cells came from him, so he is a known quality and I feel comfortable.

The BT-C3400 has almost exactly the same user interface as the BC700. The UI was the deciding factor. Same supported modes, same names for the same function, etc. makes the transition easy.

With his reply at hand, my limited patience started chewing on my ears, I hear the voice from somewhere: "Hey, you are not that young any more, do you want your charger before your first pension cheque or what? Forget the battery's expiration date, look at your own expiration date!" So, in panic, I hurried over to eBay and ordered hoping that would not be the last thing I would ever do...

So now it is a done deal - Opus BT-C3400.

Joking aside... Thanks folks. You guys have been helpful and I feel I made a good decision with your help.

With thanks
Rick


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## RI Chevy (Jun 9, 2015)

Glad you figured it out!


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## subwoofer (Jun 10, 2015)

Rick NJ said:


> I hear the voice from somewhere: "Hey, you are not that young any more, do you want your charger before your first pension cheque or what? Forget the battery's expiration date, look at your own expiration date!"



Glad you have come to a decision.

However the thought that comes to mind is if you have had this revelation, why do you bother harvesting old laptop cells and building protection onto them? Buy new ones.


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## LeafSamurai (Jun 10, 2015)

subwoofer said:


> Glad you have come to a decision.
> 
> However the thought that comes to mind is if you have had this revelation, why do you bother harvesting old laptop cells and building protection onto them? Buy new ones.




Lol. Good advice subwoofer. We only live once. Why not enjoy the good things in life if we still can and if we can afford it? It doesn't just apply to flashlights of course


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## Rick NJ (Jun 10, 2015)

subwoofer said:


> Glad you have come to a decision.
> 
> However the thought that comes to mind is if you have had this revelation, why do you bother harvesting old laptop cells and building protection onto them? Buy new ones.





LeafSamurai said:


> Lol. Good advice subwoofer. We only live once. Why not enjoy the good things in life if we still can and if we can afford it? It doesn't just apply to flashlights of course



That was how I got into 18650's to begin with. I salvaged them as an experiment and I ended up deploying them for very low power emergency lights during power outage. They supplement the Eneloops for low-power lights. For higher power, I already have SLA/old-car-battery driven 12V (LED 1-3Watt) RV lights for things like dinner, shower, etc. So the demand on the 18650's and Eneloops are for just a bit of light to avoid total darkness. So I am looking at about 100mA draw.

I am considering a bright flash light to look for our cats at night. Other than that, I can't think of anything I really need a 18650 for yet. With the "cat finder" light, I may consider a new 18650 - depending on how my old 18650 works out with the cheap flashlight I just ordered from FastTech.

Now that I can dump my home-brew chargers, the 18650's should be as easy to handle as the AA's. What do you suggest good application for a new/fresh 18650? I am itching to use it for something else, but don't really have anything in mind.


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## CelticCross74 (Jun 11, 2015)

I have used the d4 and i4 since they both came out. Both performed admirably well. Just got an Xtar VC4 though that I believe eats the D2 and 4 for breakfast. As to the above poster a great cat finding light in 18650 would be the new Nitecore MH20 which I believe Subwoofer just reviewed. Got one of those on order. Going the 4xAA route could be very wise as well for cat finding and for that you just cannot go wrong with a $50 Thrunite TN4A


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## Rick NJ (Jun 11, 2015)

CelticCross74 said:


> I have used the d4 and i4 since they both came out. Both performed admirably well. Just got an Xtar VC4 though that I believe eats the D2 and 4 for breakfast. As to the above poster a great cat finding light in 18650 would be the new Nitecore MH20 which I believe Subwoofer just reviewed. Got one of those on order. Going the 4xAA route could be very wise as well for cat finding and for that you just cannot go wrong with a $50 Thrunite TN4A



$50 for a cat-finder flash light is too much for me. I will let him get wet from the rain next time. May be he will eventually learn.

This cat has a funny habit. Normally, when you call him, he comes. But when we look for him frenetically, he actually enjoys watching. He would sit on or by the tree, and just watch us frenetically search for him before a storm.

After I tested out my new charger, I will check out the MH20 and do some flash light hunting.


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## bykfixer (Mar 5, 2016)

Thanks for another great review.

I bought an i4 a while ago thinking I'd never use LifePo4 batteries, but recently discovered they are great for a project I'm doing. 
D4 it is then. And it'll be nice to have the display as well. 

It'll be a bonus to charge 1 cell at a time.

Few days later edit:
The bundle came with a pair of D cell adapters and a car cord. 
It was a few days before I used it. I discovered a pair of C size IMEDIONS arrived completely discharged on the same evening a pair of Lion cells ran out of steam. 
Side by side C cells was out. Slots are not far enough apart for that. So it was 18mm, c size, 18mm, c size. With each slot being indepenent I could've done the order differently unlike my i4 where it likes 1,3, and 2,4 for matching cell pairs. 

Not a rapid charger for sure. The depleted batteries took about 3 hours for the 2600 mah and about 4-1/2 for the 5000mah cells, yet everything remained nice n cool. Charging 4 cells on my i4 caused concern due to all the heat. 

Next evening I decided to top up some LifePo4's, which requires a manual switch to be used to tell the machine to shut down at a lower voltage. Easy enough. You activate the slot that contains that cell, push on the mode switch to get to LifePo, done. Stab in another to activate next slot and again switch the mode. 
I'm a novice at all this modern day rechargeable stuff. But the NiteCore D4 simplicity and form of function made charging various battery sizes and chemistry a confident experience after biting my nails for the first 30 minutes of the first use. 

As I type this a pair of new eneloops just completed a top up and some new 18650's are nearly done being topped up. 

I use mainly primaries so this machine will not be used very often. However when the times comes to recharge a few rechargeables here n there I feel pretty good about using a NiteCore D4 for all the cells I own...even C size. 

Again, thanks for the review Subwoofer.


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## Milw light (Mar 6, 2016)

My D-2 lasted about 3 months & one of the slots failed to charge. This is not an uncommon problem as I've read on searches. Onward to the Opus 3400 & hopefully better luck.


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