A Real Battery "Head Scratcher" - 17650 vs 16650 Capacity

Amelia · Apr 8, 2015

Here's a real confuser:

I've been looking at 16650 and 17650 battery specs, and noticing that even though 17650 has a larger body/volume.. 16650 has LARGER mAH CAPACITY!!!

Typical:
17650 - 1500mAH to 1800mAH
16650 - 2000mAH to 2500mAH

Super confusing! What is going on here? :drool:

:thinking:

recDNA · Apr 8, 2015

Amelia said:
Here's a real confuser:

I've been looking at 16650 and 17650 battery specs, and noticing that even though 17650 has a larger body/volume.. 16650 has LARGER mAH CAPACITY!!!

Typical:
17650 - 1500mAH to 1800mAH
16650 - 2000mAH to 2500mAH

Super confusing! What is going on here? :thinking:

The 16650 is actually bigger than some 17670.

Amelia · Apr 8, 2015

recDNA said:
The 16650 is actually bigger than some 17670.

Then why is it called a 16xxx ? Isn't the first 2 numbers the diameter? :thinking:

Really confused now!

Grizzman · Apr 8, 2015

The KeepPower protected 16650s I have are smaller in diameter than the protected AW 17670s.

Most 16650s are designed to be charged to 4.35 volts, instead of the 4.2 volts of protected 17670s. The higher level of charge allows the mAh to be higher. Charging these 16650s to 4.2 volts reduces the mAh to somewhere North of 2000 mAh, but less than 2500.

The 16650s have received more engineering updates than the older 17670 cells, therefore they perform at a higher level. In the same vein, 18650s are only slightly larger than 17670s but have been designed to have up to 3600 mAh of capacity.

Amelia · Apr 8, 2015

Grizzman said:
The KeepPower protected 16650s I have are smaller in diameter than the protected AW 17670s.

Most 16650s are designed to be charged to 4.35 volts, instead of the 4.2 volts of protected 17670s. The higher level of charge allows the mAh to be higher. Charging these 16650s to 4.2 volts reduces the mAh to somewhere North of 2000 mAh, but less than 2500.

The 16650s have received more engineering updates than the older 17670 cells, therefore they perform at a higher level. In the same vein, 18650s are only slightly larger than 17670s but have been designed to have up to 3600 mAh of capacity.

So, if I buy some 16650's that are designed to be charged to 4.35V, instead of 4.2V, and I'm using an Xtar VP2 charger, would I set the voltage selection switch on the back of the charger to the "3.8V" position instead of the usual "3.6V" position? Why do they make it so confusing?

Grizzman · Apr 8, 2015

Yes, the charger should be set to 3.8V for charging 4.35V cells.

Amelia · Apr 8, 2015

Grizzman said:
Yes, the charger should be set to 3.8V for charging 4.35V cells.

Thank you!
One last question - are the 4.35V batteries safe to run in flashlights rated to 4.2V, like the SWM V11R and Nitecore SRT? Will the extra 0.15V hurt anything or burn out the electronics/emitters?
Sorry for all the questions - I'm trying to run 16650's in flashlights designed for 14500's (with extra adapter spacers) and I don't want to overlook anything.

Grizzman · Apr 9, 2015

In addition to 18650's the SRT-series lights are also compatible with two primary CR123s, so they will work fine with 4.35 volts.

As far as I know, the V11R only accepts 16340 or 14500 sized cells (with an optional extender). I don't have one to know if the extender will allow a 16650 to be inserted.

Here's a related thread.

http://www.candlepowerforums.com/vb/showthread.php?390207-Sunwayman-V11r-extension-question

Amelia · Apr 9, 2015

Grizzman said:
In addition to 18650's the SRT-series lights are also compatible with two primary CR123s, so they will work fine with 4.35 volts.

As far as I know, the V11R only accepts 16340 or 14500 sized cells (with an optional extender). I don't have one to know if the extender will allow a 16650 to be inserted.

Here's a related thread.

http://www.candlepowerforums.com/vb/showthread.php?390207-Sunwayman-V11r-extension-question

I'm using the SRT3 head - it's only designed for 1 primary or rechargeable cell, 4.2V max.
No, the SWM V11R extender won't allow 16mm cells - at least not until I get a pair of them bored at a machine shop (2 of them, in order to get the extra length required for 16650).
Do you think the extra voltage of the 4.35V cells will damage either light?

Grizzman · Apr 9, 2015

I highly doubt the extra voltage would cause any damage.

reppans · Apr 9, 2015

A Real Battery "Head Scratcher" - 17650 vs 16650 Capacity

If you're looking at the protected 2500mah 16650 Keeppowers sold by Illumn, then the protection circuit is set at 4.20V (per the specs). Based on HKJ's last review of the 16650 Keeppowers (2000 mah version), he found the mah difference between charging to 4.20 vs 4.35 to only be ~80 mah difference.

Chicken Drumstick · Apr 9, 2015

Amelia said:
Thank you!
One last question - are the 4.35V batteries safe to run in flashlights rated to 4.2V, like the SWM V11R and Nitecore SRT? Will the extra 0.15V hurt anything or burn out the electronics/emitters?
Sorry for all the questions - I'm trying to run 16650's in flashlights designed for 14500's (with extra adapter spacers) and I don't want to overlook anything.

As another poster said, the mAh difference is likely to be small between 4.2 and 4.35v, have a look at HJK's site for examples of this.

If you are worried about the voltage increase, play it safe. Or if you are the more daring type, try it out and see, but going beyond manufacture specs always comes with risk.

RetroTechie · Apr 9, 2015

Grizzman said:
Most 16650s are designed to be charged to 4.35 volts, instead of the 4.2 volts of protected 17670s. The higher level of charge allows the mAh to be higher.

The contrary, actually! Yes, a higher voltage at same mAh represents more energy. But energy content doesn't automagically increase simply by allowing a higher charge voltage. For example separation between electrode materials might have to be increased to allow for that higher voltage. Which means more volume / electrode surface area -> less total surface area in the same volume.

So for 2 batteries that are technology-wise "on par", and same size but different voltage, I'd expect the higher voltage one to have less mAh to compensate. Of course that voltage difference may indicate a difference in technology (and with that, energy content / volume).

The 16650s have received more engineering updates than the older 17670 cells, therefore they perform at a higher level. In the same vein, 18650s are only slightly larger than 17670s but have been designed to have up to 3600 mAh of capacity.

Probably the real reason. A simple matter of how much effort was put into optimizing specific battery types / sizes.

fivemega · Apr 11, 2015

Amelia said:
Then why is it called a 16xxx ? Isn't the first 2 numbers the diameter?

All those numbers such as 16xxx or xx650 are nominal and not very accurate size and measurements.
They just give you some idea that what you are dealing with.
Not all companies make exact measurement for batteries. Some concern about best fitting, some concerns about maximum possible capacity.
Protected batteries use some metal strap for electrical contact that will increase diameter.
Some companies use thicker heat shrink jacket and foil sticker that will increase total diameter even more.
Protected batteries use PCB for voltage and current control that will increase length.
Some companies use bigger PCB that will increase the length even more.

recDNA · Apr 11, 2015

Grizzman said:
The KeepPower protected 16650s I have are smaller in diameter than the protected AW 17670s.

Most 16650s are designed to be charged to 4.35 volts, instead of the 4.2 volts of protected 17670s. The higher level of charge allows the mAh to be higher. Charging these 16650s to 4.2 volts reduces the mAh to somewhere North of 2000 mAh, but less than 2500.

The 16650s have received more engineering updates than the older 17670 cells, therefore they perform at a higher level. In the same vein, 18650s are only slightly larger than 17670s but have been designed to have up to 3600 mAh of capacity.

I have a quark that protected 16650 does not fit in yet safefire 17670 does. I think the sanyo inside the protected keeppower is 16650 so obviously the thicker protected model containing the sanyo 16650 is thicker. The AW 17670 is even thicker but the safefire 17670 is thinner the both. Go figure.

Overclocker · Apr 12, 2015

Grizzman said:
The KeepPower protected 16650s I have are smaller in diameter than the protected AW 17670s.

Most 16650s are designed to be charged to 4.35 volts, instead of the 4.2 volts of protected 17670s. The higher level of charge allows the mAh to be higher. Charging these 16650s to 4.2 volts reduces the mAh to somewhere North of 2000 mAh, but less than 2500.

The 16650s have received more engineering updates than the older 17670 cells, therefore they perform at a higher level. In the same vein, 18650s are only slightly larger than 17670s but have been designed to have up to 3600 mAh of capacity.

if base cell sanyo UR16650ZT. 4.30v

UR16650ZTA. 4.35v

A Real Battery "Head Scratcher" - 17650 vs 16650 Capacity

Amelia

Enlightened

recDNA

Flashaholic

Amelia

Enlightened

Grizzman

Flashlight Enthusiast

Amelia

Enlightened

Grizzman

Flashlight Enthusiast

Amelia

Enlightened

Grizzman

Flashlight Enthusiast

Amelia

Enlightened

Grizzman

Flashlight Enthusiast

reppans

Flashlight Enthusiast

Chicken Drumstick

Flashlight Enthusiast

RetroTechie

Flashlight Enthusiast

fivemega

Flashlight Enthusiast

recDNA

Flashaholic

Overclocker

Flashlight Enthusiast

Similar threads

Latest posts