Nitecore vs Opus C3100 charger

As @Siam Diesel said, they are excellent flashlight batteries but not suitable for vaping.

 

I got a Nitecore D4 when I started vaping. All the flashing numbers look good, but after the first ten minutes, I never looked again, except to check if finished. Then it died. So I got an i2 from one of our vendors. Same safety, much cheaper.

 

The opus additional functions look useful for troubleshooting and testing mah etc, but not sure the average vaper would need those that often.

I use xtar and nitecore, currently more nitecore. I specifically bought the xtar (after chatting to @Siam Diesel on here) as they advertise being able to wake up sleeping lions. Not that I was able to wake the lions I wanted to, because they seem to be hard rather than soft fused, but at least there's a chance I would be able to do it in the future, if I needed to.

If you like things neat (and don't like extra expenses) then nitecore D4 includes the mains wall wart in one box and will charge an RX200's batteries in one sitting.

Xtar's require additional wall warts (available from Amorn in Thailand), my VC2's needed 2A or 3A 5V to charge at full tilt.

Lastly always try to buy from a reputable vendor, and do check the authenticity of the product, fakes are out there.

 

Looks like all xtars need external wall warts and don't have capacity to use mains direct, VP2 is a 12V 1A wall wart according to the specs. nitecore d4 and i4 have mains tranny inside the box, so can be operated sans wall wart, I didn't check the whole range for direct mains to charger, the OP can do that for himself when he makes his choice.

And, yeah, I remember you saying about your LGs. My conclusion was/is that overdischarge protection varies from manufacturer to manufacturer, so mine didn't wake up even with xtar charger. Xtar specifically talk about waking up sleeping lions as a feature, whereas I don't think nitecore do.

 

The power supply located outside the unit has some advantages when it comes to heat. Units with external power supplies generate less heat close to the batteries. The Nitecores generate more internal heat because of the internal power supply. You see a lot of info at Flashlight information

 

This is possibly true with D4, however tranny is well ventilated, and doesn't seem like it could heat the batteries as its a distance away from them. Not noticed any issues with hot batteries, using day in day out for 6 months, if anything the opposite because max charging current on D4 on 18650s is 750mA and this reduces with multiple cells being charged at the same time. Obviously the lower the amps of charging current, the less potential risk of overheating bats.

I'm not aware of a charger that's available for retail pricing, that includes any temperature monitoring of the kind that's in laptop battery packs (sensors adhered to cells and a monitoring chip). So, there's always a slight risk of overheat problems with any of these chargers, whether wall wart or internally mains to DC.

Also, a thermal runaway on the battery is more likely caused by an internal fault with the battery, rather than the charger. The charger couldn't be ruled out if it had been charging incorrectly for that battery, lion charging has limits and different phases and even good quality electronics can develop faults.

Presumably a DIY safety shutdown device that monitors temperature of cells could be built with arduino or raspberry pi, temp sensors and a relay to shut down the charger, for not much money and a little hard work. But, I am yet to be convinced that when using authentic relatively new trusted name bats, with authentic trusted name brand chargers that this is neccessary for safety.

The only downside I could find with D4 is an above mentioned advantage, that is current is limited in charging which leads to a potentially slower charge than some others. But that's an advantage in safety terms. Oh, and the D4 won't charge 4x 26650s at the same time, but I don't think any of the 4 bay chargers I've seen are able to do that. Best for 4x 26650s is to charge them on 2x 2 bay chargers.

Within that my xtars work flawlessly too, only bugbear was the wall wart not being included in the box, which could be solved as SD pointed out by spending more money on VP rather than VC series.

 

It's really up to each person to decide what they want in a charger and I think all the well made name brand chargers are safe. The only point I was making is about the internal heat and how it affects the batteries. Here are some thermal pics for comparison.


The Nitecore i4 has the Hot Spot at 71.4 C. The batteries themselves are around 40 C.




The Nitecore D4 has the Hot Spot at 53.3 C. The batteries are around the same as the i4 at ~40 C



The Xtar VC4 has the Hot Spot at only 37.1 C and the batteries are running ~30 C. That's 10 degrees C cooler than in the Nitecores. Is it a safety issue? No. Do the batteries run cooler? Yes.


You can clearly see from the above images where the internal power supply is and the heat that it adds to the charger.

 

Source for photos ? I'm sure it's reputable, and tests where carefully scientifically conducted over many charging cycles with different brand batteries in an environmentally controlled situation, with like for like charging current, etc, but, without a source and description of testing carried out etc, then generally I dunno ... Maybe conclusive, maybe not, who knows ...

Agreed, totally, each person should buy whatever charger they want and listen to their own personal opinion. However the OP asked for our opinions, hence sharing them here, mostly which people like you and I do in the spirit of vapers helping vapers, with positive intentions.

None of these scenarios are 100% safe without continuous monitoring of temperature like in laptop battery packs or similar. So there isn't really a safer, and not so safe, as far as I can see, in what we're discussing, as even with your temperature photos from the unknown source, all temperatures are presumably within manufacturer's normal operating tolerances for batteries and within charger manufacturer's tolerances. I don't think thermal runaway occurs because "it's a hot day", otherwise we'd have lions exploding all over Thailand all the time and they couldn't be sold in some countries at all.

 

Source is from the link I posted before. Flashlight information Very reputable and unbiased reviewer.

His comments on the Xtar VC4 even mention the fact the cell temperature stays low.

Conclusion

The charger is very good at both LiIon and NiMH charging and keeps some impressive low cell temperature during charge (Like the VC2).
For charging at full current the charger is fairly demanding of the used usb power supply. It is possible to use weaker supplies, but the charging will be slower or sometimes much slower. With the current dial it is easy enough to see when that happens and it is time to get a better usb power supply. I would have liked slightly better performance with weak usb power supplies.

This type of charger is what I will call a family charger. Nearly anybody in the family can use it, just put the batteries into the charger and wait. Only caveat is that small batteries go into the two center slots or, for sets of four, in all four slots.

Final conclusion must be that it is a good charger.

 

Thanks @Lotta , I've heard of this guy and is definitely one of the better sources out there, who does seem to weed out fakes etc, and is doing extensive testing, within limits of his resources. So thanks for sharing

Checking his page for D4 he doesn't indicate test conditions things like ambient temperature, what stage in charging cycle, number of tests performed, etc etc. (perhaps this is documented elsewhere on his site/page ?) So, personally, I'd take these photos with a pinch of salt, and dunno whether they are suitable for direct comparison charger vs charger for worry about differing test conditions influencing any conclusion. I mean ambient temperature can vary as much as + or - 40 degrees C in UK, seasonally, for instance, Thailand range I've seen locally was maybe between 20 to 55 deg C. Just one factor.

More accurate data would be obtained by nailing down as many of the variables as possible so they are the same between tests, and repeating tests many times to reduce the likelihood of one offs occurring. And obviously same between test subjects.

Already agreed with you early on that mains tranny probably generates heat, but interesting discussion nevertheless. I'll do some more tests my end, who knows I might be fully converted to the xtar evangelist's flock ...

 

I am speculating here but I would assume this is done in his "lab" and the ambient temperature would be consistent. Again, speculation but I would also assume that with the number of products he tests, he has a pattern to his methods and tests should be consistent from one product to another. With the amount of data he supplies about the chargers and all of the measurements he takes in addition to the temperature testing, I feel confident in his reviews. He obviously has very sophisticated equipment to supply this data and I don't think he would vary from a set test plan or allow an obviously different method to be used.

 

LOL, you're funny ... Well I'm speculating here but could be a guy in his underpants in his mom's basement with equipment off of eBay. Overall, I didn't concur with your conclusions from the source data provided, and explained why. I don't think either of us has access to facilities to do the required accurate and scientific testing, therefore we may never know anything conclusive other than opinions. So we'll have to agree to disagree, nothing personal.

Oddly enough I just converted a spare PC power supply into a wall wart graveyard for DC 12v/9v/5v gadgets and USB charging, so I'll likely run my lion charging off of that going forward, also as a bonus, should be more efficient as only using power on demand. It'd be DC12v into the nitecore D4, thus mains tranny inside D4 would be dormant, so less heat near the batteries as we were discussing. Happy Days