3400mAh Panasonic NCR18650B

[Mooreshire]

Re: Panasonic NCR18650B

Very exciting news about the 3400mAh technology announcement.

As for Orbtronic, the key is to wait and watch. Even the Amazon price for a pair of 2900mAh cells direct from them has fluctuated nearly 100% over the last two weeks (I just scored four cells for $24, suddenly that is less than the price for only two - same amazon listing, ten days apart)!

 

[tobrien]

Re: Panasonic NCR18650B

Very true, HKJ. This is the reason that for me and my applications, I favor the Samsung 30A and LG 4.35 Volt cells over the Panasonic 4.20 Volt cells. I must say I was a bit disappointed that these new "B" cells are actually 4.20 Volts. I really need the extra voltage available under load. Also, the capacity below 3.00 Volts (under load), of any of these cells, doesn't do me any good.

Dave

wait, so having a higher voltage rated battery, like a 4.35v ones, is better and perhaps yields more voltage available to the emitter when under load and at a lower capacity left in the cell? am I correct? does it matter if you only charged a 4.35v cell to 4.2 volts on a standard li-ion charger?

Very exciting news about the 3400mAh technology announcement.

As for Orbtronic, the key is to wait and watch. Even the Amazon price for a pair of 2900mAh cells direct from them has fluctuated nearly 100% over the last two weeks (I just scored four cells for $24, suddenly that is less than the price for only two - same amazon listing, ten days apart)!

that's a good point

 

[HKJ]

Re: Panasonic NCR18650B

wait, so having a higher voltage rated battery, like a 4.35v ones, is better and perhaps yields more voltage available to the emitter when under load and at a lower capacity left in the cell? am I correct? does it matter if you only charged a 4.35v cell to 4.2 volts on a standard li-ion charger?

Using my battery comparator you can easily find the answer to these questions.

Here is a comparison between 4.35 and 4.2 volt charge voltage, as you can see the 4.2 volt charge has lower voltage and less capacity.

 

[tobrien]

Re: Panasonic NCR18650B

Using my battery comparator you can easily find the answer to these questions.

Here is a comparison between 4.35 and 4.2 volt charge voltage, as you can see the 4.2 volt charge has lower voltage and less capacity.

thanks buddy!

so since the 4.35 volt batteries would be used without a protection circuit and so on, should i stop using them in a light sooner (i.e.: at a higher resting voltage) than a 4.20 volt battery would normally stop at?

 

[HKJ]

Re: Panasonic NCR18650B

thanks buddy!

so since the 4.35 volt batteries would be used without a protection circuit and so on, should i stop using them in a light sooner (i.e.: at a higher resting voltage) than a 4.20 volt battery would normally stop at?

This depends on the battery, you can get batteries with 4.2 volt charging that can be discharger to 2.5, 2.8 and 3 volt. I do not have the data sheet for the LG cell, but I would say stop at 3 volt. This stop is when drawing current, I cannot tell what the resting voltage is.

 

[45/70]

Re: Panasonic NCR18650B

wait, so having a higher voltage rated battery, like a 4.35v ones, is better and perhaps yields more voltage available to the emitter when under load and at a lower capacity left in the cell? am I correct? does it matter if you only charged a 4.35v cell to 4.2 volts on a standard li-ion charger?

Hi tobrien. I think HKJ pretty much covered your questions. It's not so much the available voltage to the emitter, this is controlled by the driver limiting the current. It is the available voltage to the driver itself that is the problem.

For example, my primary interest regarding voltage held under load, relates to download's 8th run Pocket Rocket. This light draws close to 3A on high. It is also one of, I believe, only two lights made, with a driver that has a low voltage warning that kicks in at ~3 Volts.

To make matters worse, the light body is made from titanium, which is a poor electrical conductor. I've done a tailspring mod, ala M@g, to reduce the resistance in the light's electrical circuit, but still, keeping the voltage as high as possible is important to enable the light to run at the high level, as long as possible. As it is, an IMR 1600mAh cell will run the light almost as long as a 4.35 Volt Samsung 30A cell.

The lower levels are not really affected. In fact, the 30A cell will run the light at medium, or low, for a long time, after the warning kicks in on high, whereas the IMR cell is pretty much "done" at this point. The difference is that the IMR cell holds higher voltage under load, compared to the Samsung 30A, but runs out of steam much sooner, as it is only about half the capacity.

Dave

 

[Shadowww]

Re: Panasonic NCR18650B

The difference is that the IMR cell holds higher voltage under load, compared to the Samsung 30A, but runs out of steam much sooner, as it is only about half the capacity.

Hey Dave, you should really check out LG 4.35V cells if Samsung ones don't give you any advantage over IMR's.. because they (LG's) will (at 3A current you quoted)

 

[45/70]

Re: Panasonic NCR18650B

Hey Dave, you should really check out LG 4.35V cells......

Yeah, I too have been studying HKJ's charts, and other's for some time now. The LG 4.35 Volt cells do look to be an excellent choice, better than the Samsungs. Thanks for the tip though!:thumbsup:

One thing I've noticed, in my own testing, AW's IMR 1600mAh cells fare a bit better at 3A, than in his results. Still there's no way around it, they're still a low capacity solution, even though they work very well. The IMR's OC voltage at the voltage warning point is 3.60-3.65 Volts, whereas the Samsung 30A cells read ~3.80 Volts OC. So, there's no doubt that the IMR cells are quite capable of supplying 3A until the cell is pretty much discharged.

Well, going OT here I guess, my apologies.

Dave

 

[TEEJ]

Re: Panasonic NCR18650B

I typically want to know how low the cell discharges to before its "too low", and many (Most?) of the higher mAh rated cells got the higher rating by simply being ABLE TO function down to a lower discharge limit.

This is because most of my LIGHTS don't use the cells below ~ 2.9 - 3 v or so...so, they drain them from ~ 4.2v or so down to ~ 3 v, and the light's protection kicks in, and disables high, or whatever...as the cells gets down to the programmed limits of the light.

For the ~ 3v limit lights:

A cell that can only go down to ~ 3 v from 4.2 v, but is rated at 3100 mAh, would be better as far as run time, than a light that was also rated at 3100 mAh, but was rated as being able to drain down to say 2 v, etc.

 

[bshanahan14rulz]

Re: Panasonic NCR18650B

I think at this point, datasheets are still for ndc signers eyes only :-/

 

[Colonel Sanders]

Re: Panasonic NCR18650B

I have some of these cells on order and will be posting some test data soon after arrival.

I still don't know for sure if these cells are intended to be charged to 4.35 or 4.2v. Anyone know *for sure*? Thanks.

 

[Colonel Sanders]

Re: Panasonic NCR18650B

According to Keeppower's website, it is 4.20v.

 

[Shadowww]

Re: Panasonic NCR18650B

Considering it's just a updated NCR18650-series, I'd also say it must be 4.2V, if it'd be 4.35V it wouldn't be NCR, it'd get assigned some other series-name.

 

[bshanahan14rulz]

Re: Panasonic NCR18650B

officially 4.2V. may gain up to 100mAh from 4.35V charging, in some of the more extreme examples, from what I hear.

 

[jirik_cz]

Re: Panasonic NCR18650B

I can confirm they are 4.2V. Just did a first discharge and got a claimed capacity from a cell charged to 4.2V...

 

[Helmut.G]

Re: Panasonic NCR18650B

I can confirm they are 4.2V. Just did a first discharge and got a claimed capacity from a cell charged to 4.2V...

Awesome, thanks!

At what voltage did you end the discharge?

 

[tobrien]

Re: Panasonic NCR18650B

what do the letters at the end (B) for example, signify?

 

[Colonel Sanders]

Re: Panasonic NCR18650B

I don't know but the A model was 3100 and the one with no letter at the end was 2900.

 

[jirik_cz]

Re: Panasonic NCR18650B

So, here are some of my graphs and I have to say that these cells are very impressive! Tests are done with CBA II.

 

[Colonel Sanders]

Re: Panasonic NCR18650B

"and I have to say that these cells are very impressive!"

Wow! I'd have to agree! Very nice. :thumbsup: Thanks for the graphs. I really like that you included the mWh data as that's really what we should be looking at instead of mAh.