Test/review of Lumintop 18650 3400mAh usb (White) LM34C

Lumintop 18650 3400mAh usb (White) LM34C







Official specifications:

  • With Micro USB rechargeable adapter

  • Special charge management with 2 colors LED indicating charge condition(Red?charging; Green: Full)

  • Suit to normal 18650 flashlight and electronic apparatus using 18650 batteries

  • Up to 3400mAh high capacity which promises longer runtime

  • Using Panasonic NCR18650B cell, which enjoys top quality and excellent performance.

  • Incredible anode protection circuit protects against overcharge, over discharge and short-circuiting.

  • Economical and environmental-friendly as it allows more than 500 times charging and discharging.

  • Max output current reaching to 4 ampere makes 18650 compatible with various kinds of high-drain devices.

  • Tough metal supporting protector to guard agaist circuit abrasion.

  • Coated with durable metallic film to guard against abrasion.

  • Capacity: 3400mAh

  • Nominal voltage: 3.7V

  • Charging cycles: 500 cycles

  • Charging current: 1A (Recommended) 2A (Max)

  • Size: Length: 2.78” (70.7mm), Diameter: 0.73” (18.6mm)

  • Net weight: 1.69oz(47.8g)




This is a fairly high capacity battery with build in usb charger and protection.












The usb input is placed at the top of the battery. The two small holes are for a red and green led to show charging and done.



The performance is as expected with the used cell, the protection adds a slight voltage drop at higher current (As protection always do). The cell is rated for 4A and can mostly deliver 5A before the protection trips, at 7A the protection will trip fairly fast.





The cell gets warm at 5A, but nothing problematic.











The protection will trip at about 8A, but when the cell warms up the limit will be lower.



The above charging is done with a normal round cell charger with 1A charge current.



Here I am charging with the usb port. The current is a bit lower, this means longer charge time. The termination current is about 50mA, this is a good value for getting maximum capacity.



This discharge is done after the above charge. The cells did get slightly more capacity than I got in my test.



Conclusion

Interesting idea to build a charger into the battery and very practical if you carries something with only one 18650 cell, it can be charged from a phone charger, from a PC or from a power bank.

I only see one disadvantage with the battery: The size, it is a very long 18650 battery and not much equipment will be able to handle that long size.

The performance of the battery is good and the current limit will protect the battery from mistreatment.



Notes and links

The batteries was supplied by Lumintop for a review.

How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries
Compare to 18650 and other batteries

Thanks for the review. Is there actually parasitic drain as a result of this built in charger?

There will be some, probably some uA. This is insignificant.
I hope to get time to open one up, that would also be a good time to measure the standby current for both protection and charger circuit.

I dont have a single light that can accomodate the length

How do you know this for sure? Of course it should be in the order of microA, but is there a reason to think so? The Lumintop SD75 has got a charging/powerbank function it the tailcap. The current drain of the tailcap (not the driver) on my two samples are 2 and 6 mA(!). Lumintop told me that it should be 0.6 mA. Anyhow, there is an on/off switch in the tailcap that activates USB out and battery status. So when this button is in OFF position, you only have the charging function left. So apparently, the PCB for the charging function results in these high drain values, at least that is what I suspect. Therefore I suddenly became curious in the parasitic drain value for this battery.

I have tested a couple of charges with a single chip, they are usual very low in current draw. I would not expect any modern single charger chip to have a large current draw when unpowered (that would not be a very useful chip).

I see, great, thanks!

A great review as usual. But I have no interest in having an 18650 with a built in charger. It may be great for a newbie with only one single cell flashlight, but not for most of us flashaholics.