Great 18650 Batts

[Brenner]

Just (2) 1 Ohm 2% 5 Watt resistors in series, the battery, a multimeter, and some math! :beer:

Sorry, only last piece of equipment I can identify :beer:



You are the only one who is actually on topic in this thread.

I would like to apologize to the guy who started this thread, I get carried away by cells other than Panasonic NCR 18650A 3100mAh .

I was asking about equipment, because it would be cool to “fire-up” this li-ion chemistry, and see how much “juice” you can squeeze from them at different current levels.

There are many reviews on CPF and BudgetLight forums, but I did not see them here.




Really nice DIY project of yours.

 

[danefex]

Thanks for this information guys, I just placed an order with them :beer:

 

[Brenner]

Thanks for this information guys, I just placed an order with them :beer:

That is some dangerous arsenal.



What is secret ingredient inside Solarforce hosts ?

 

[danefex]

That is some dangerous arsenal.

What is secret ingredient inside Solarforce hosts ?

Both of those are just under 2W of 445nm :beer:

 

[HaloBlu]

Just ran into another option for charging 4.35v cells. $23 smart charger 0.5a 4.35v cutoff

 

[Brenner]

Just ran into another option for charging 4.35v cells. $23 smart charger 0.5a 4.35v cutoff

Don't get me wrong , but I do not want to have anything with "recommendations" which will ultimately lead uninformed customer to big disaster (burned house, or personal injury).

My only recommendation for folks with not enough knowledge about Li-ion chemistry/batteries is:

Please go to BatteryUniversity.com web site and read. That's all you need > read and arm yourself with knowledge before you start using ANY Li-ion cell.


I choose Panasonic NCR-18650-A 3100mAh with really good reason.

 

[Brenner]

Nice batts you got there !
If your calculations are correct then these bats must be the best on the market !

Jim

Yes Jim,

Panasonic 3100mAh NCR18650A are the best on the market currently.

There is no 18650 battery that can be compared (capacity, safety) with these monster 18650 cells.

If this is important to anybody:

This NCR battery is made in Japan.



:beer:

 

[justinjja]

Just (2) 1 Ohm 2% 5 Watt resistors in series, the battery, a multimeter, and some math! :beer:

Did you include the resistance of your multimeter in your calculations?
It is probably in close to .1 ohms unless your are using a shunt instead of directly measuring current with a multimeter

 

[Blu Ray]

Would these work with any laser that takes 18650 or is it too powerfull?

 

[Brenner]

Would these work with any laser that takes 18650 or is it too powerfull?

Yes Sir,

Panasonic NCR18650A 3100mAh (or 2900mAh cheaper version) will work with any laser or flashlight that runs on 18650 battery cell.

 

[Jufran88]

If you follow Drlava's thread on how to calculate the internal resistance here: "http://laserpointerforums.com/f67/how-healthy-your-batteries-how-measure-internal-resistance-57576.html"

Your just measuring the voltages of the battery and the battery under a load. You then use the formula he provided to calculate the internal resistance.

Did you include the resistance of your multimeter in your calculations?
It is probably in close to .1 ohms unless your are using a shunt instead of directly measuring current with a multimeter

 

[Brenner]

If you follow Drlava's thread on how to calculate the internal resistance here: "http://laserpointerforums.com/f67/how-healthy-your-batteries-how-measure-internal-resistance-57576.html"

Your just measuring the voltages of the battery and the battery under a load. You then use the formula he provided to calculate the internal resistance.

And do not forget that lab test environment is quite different than a real life, normal conditions.

 

[Fiddy]

they'd work better with a laser that can handle a 4.35VDC input

 

[Brenner]

they'd work better with a laser that can handle a 4.35VDC input

Yes, you are right. Fully charged Panasonic 18650 3100mAh are 4.2V, and will go all the way down to 2.5V without problem.

Other 18650 can go only to 2.75V, where they reach dangerous level of discharge.

That doesn't mean that other batteries are bad, but simply cannot compete with
NCR cells.

 

[Brenner]

For people who want to know more about these NCR18650A batteries.

This is very useful link / specs. discharge rates at various discharge current settings, and temperature environment /

http://industrial.panasonic.com/www-data/pdf2/ACA4000/ACA4000CJ255.pdf

For US folks - don't get confused - temperature is in Celsius

To make it more interesting for geeks that "like" to play with math here is the magic C-F magic formula:

°C x 9/5 + 32 = °F

to make it even easier:

Fahrenheit Degrees = (1.8 x Celsius Degrees) + 32


:beer:

 

[BShanahan14rulz]

One downside that I see is that it is recommended that you only charge the NCR18650A at rates at or below 0.885A.

There are a lot of good things about this cell, though. I like the added capacity without the higher termination voltage, but I don't like how some of the capacity comes from discharging it lower than what is standard practice. but if you use a standard protection circuit, it will be very conservative and no worrying about overdischarging the cell.