Test/Review of AWT IMR18350 700mAh (Yellow)

Batteries and Chargers Rechargeable Batteries
1

AWT IMR18350 700mAh (Yellow)

Button top version



Official specifications:

  • Rated Capacity: 800mAh (0.5CA Discharge)
  • Rated Voltage: 3.7V
  • Internal Resistance: <100mOh (with PTC)
  • Cut-off Discharge Voltage: 2.75V
  • Charge Upper Limit Voltage: 4.20±0.05V
  • Charging Time(Std): 4.0hours
  • Standard Charging Circuit: 0.2C A
  • Charging Circuit: 0.5C A
  • Standard Discharging Circuit: 0.2C A
  • Fast Discharging Current: 0.5C A
  • Max Discharging Current: 2C A
  • Weight: about 21.5g
  • Height: 65mm
  • Operational Temperature: charge (0 ~ 45°C), discharge (-20 ~ 60°C)
  • Storage Temperature: within 1 month (-20~ 50°C), within 3 months (-20~ 40°C), within 3 months (-20~ 20°C)




This is a high current 18350 cell. It has 6.4A continuous and 10.5A pulse rating.










The is some capacity difference between the two cells. It easily handles loads up to 5A, but has problems at 7A and cannot do 10A.















Flat top version



Official specifications:

  • Nominal Voltage: 3.7v
  • Capacity: 700mAh
  • Standard charger: cc/cv(max ,charging rate 2A)
  • Cycle Life: >1000cycles
  • Max .continuous discharge rate:6A
  • Operating Dishcharge Temperature: under10 and over 60 Degree Celsius
  • Dimensions: 18.15x49.82mm




Same cell as above, but this time in flat top version. It has slightly less capacity.











These cells handles 7A better.















Conclusion

The cells has very good performance at high current, but the difference between the cells means that they are best used one at a time (i.e. not in series).



Notes and links

The batteries was supplied by AWT 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
Comparison to other LiIon batteries

2

Nice review hkj but which lights use this size of battery

3

It is probably most used in custom lights (Like: http://lygte-info.dk/review/Review%20Lux-RC%20FL33%20UK.html ). It can also be used in some lights that can use 1x18650 or 2xCR123, if the brightness is a bit low on 18650, but the above batteries are not recommended for that.

4

Thanks for testing all the small cells too.
Is the difference between BT and FT because of the contact resistance of the button?
Where to buy the Awt cells? Fastech sells the 18350 800mAh for 5$, are there other sources?
I am currently looking for some short Imr cells and the Awt18350 and the efan18350 seems to be the best you tested. I have some efest 16340 and 18350 on order but the 18350Awtand Evan are better judging from your comparator.
As I never had or heard from awt/efan I am a bit suspicious especially because it are unprotected imr cells…

5

I believe the difference is due to 3 factors:

  • The button top adds some resistance
  • Less contact surface may add some resistance
  • The contact resistance in my rig may vary slightly between batteries.

All 3 is in the very low milli ohm range.

I could fix the two contact resistance issues by switching to a fully 4 terminal rig, but that would also mean that all batteries I tested in the future will look slightly better at high current. I have not decided if I am going to switch.

6

You could maybe compensate for the contact resistance in older measurements in the comparator to keep them comparable with new results.

7

+1

You should be able to work out (i hope) a multiplier that make the results comparable.