YongNuo SF-18 External Battery Pack for Canon Speedlites Review

YongNuo Digital is for a long time well known to strobists for their decent quality, lower priced speedlite flash units as well as their radio remote flash triggers.
Beside that, they do make some other accessories as this SF-18 External Battery Pack for Canon presented here.


YongNuo SF-18 is identical in appearance and function to Canon's own CP-E4 External Battery Pack.

Batteries in older Speedlites or more current Speedlite 580EX II, 600EX-RT and Macro Lite MT-24EX and MR-14EX II flash units usually provide enough power for most uses. But when sometimes a big number of photos requires a flash or in case the flash needs to recycle really quickly and want to use a high power burst of flash frequently. An external battery pack provides exactly the extra power source to help you accomplish the task.

Especially strobists who make use of flash extensively should consider an external battery pack like the Canon CP-E4 or a well made clone like the YongNuo SF-18 at a fraction of the cost. Eight extra AA batteries, reduce the flash recharge time drastically while they extend the time between battery changes.

Packaging & Contents

YongNuo besides the deliberate copy of the Canon Battery pack does also copy the Canon packaging and colors. However, resemblances stop here, since the photos on the box show the SF-18 Battery Pack and the 3 different connector plugs for Canon (also compatible to YongNuo), Sony and Nikon Flashes. A small label, besides the model number on the front of the box, differentiates the contents.

Wrapped in the box exist the External Battery Pack with its coiled cable, a versatile soft padded case, a long 1/4"-20 thumb screw with a rubber gasket and a sheet of paper with operation instructions . 

The Battery Pack

The casing and features are exactly the same as with Canon's CP-E4 and if it weren't for the YongNuo labels it could be easily mistaken for it.

YongNuo SF-18 External Battery Pack manual page is simple and basic naming the parts and explaining  how to open, load and attach the pack on a camera (click to enlarge).

The Carrying Case

The soft padded nylon case that accompanies the SF-18 battery pack is also a replica of the relevant Canon counterpart. The top flap is equipped with a Velcro tape while the bottom flap is equipped with a puss stud which supposedly opens more difficultly and will ensure the enclosed battery pack won't slip off. There is also a small strap on the front also equipped with Velcro either to be used as a cable holder or aid strapping the case somewhere.

The rear side of the case features a dual strap loop for either vertical or horizontal attachment of the case on a strap or a belt.

The top flap has an opening that allows for the connector cable to exit as well as for the operation light to be visible. On the other hand the lower flap allows for the battery tray to be drawn out without a need for the battery pack to be removed from the carrying case.

The Battery Tray

By pushing-in a small button at the bottom of the battery pack body and sliding the cover a little to the right, the battery tray pops out a bit. Then it is easy to pull it out all the way revealing all of the eight battery cell sockets.

There are clear marking on the plastic battery tray regarding the orientation and polarity of each battery cell (bottom left photo). After loading the tray with eight fresh AA alkaline batteries or eight fully charged rechargeable batteries like the SONY Eneloops shown above, the tray is pushed into the battery pack casing. Pushing in and sliding the cover to the left, the tray is secured with a faint but audible click.
Should I mention here, that it is recommended to use in the SF-18 battery pack the same type of batteries you use in your Speedlite flash unit.

Using with a Flash
Following are a couple of examples of how the SF-18 is connected to the Canon 580EX II and the Canon 580EX Speedlite flashes.

YongNuo SF-18 External Battery Pack connected to Canon Speedlite 580EX II just by lifting the hinged rubber cover of the external power source socket on the left side. The external battery plug is equipped with a rubber gasket that insulates the connector and maintains the weather sealing of the 580EX II as well as on the newest 600EX-RT Speedlites. 

In the same way YongNuo SF-18 External Battery Pack is connected to the older Canon Speedlite 580EX after removing the external power source socket and bracket fitting rubber cover on the left side. The Speedlite 580EX does not promise any weather sealing though. 

Both 580EX and 580EX II Speedlites may control via their C.Fn-07 and C.Fn-12 respectively the recharging source. By default these Custom Functions are set to 0 where the flash recharges using both the internal batteries and the external battery pack in which case when the internal batteries get exhausted first, shooting might not be possible. However, if the respective C.Fn is set to 1 the flash recycling will be powered only by the external battery source saving the internal batteries only for flash control functions, therefore the internals will last longer.

Attachment Methods

Directly Attached on a Camera
By being a direct replica of the Canon CP-E4 battery pack, the SF-18 maintains the ability to be attached on a camera tripod socket at its bottom via a long 1/4"-20 thumb screw.

Once more coming from Canon the SF-18 has a pass through hole in the upper section which accepts the long stem 1/4"-20 screw.

After passing through the long screw, which actually requires a little screwing at the end so as to stay on as a captive screw, then the accompanying rubber gasket should be set acting as an insulation between the battery pack end the camera base. 

Finally, the YongNuo SF-18 External Battery is mounted on the base of the camera or the camera battery grip in this case. However, considering the bulk of a Gripped Canon EOS 7D + speedlite 580EX II on top, I wouldn't recommend this method at all, unless your physique permits heavy weight lifting for exercise.

Attached on a Waist Belt or a Camera Bag Shoulder Strap
Since the SF-18 spiral connector cable has ample length to allow for movement, a more appropriate carrying method would be by attaching the carrying case via its dual strap loop on the back.

Here the SF-18 External Battery is shown with a waist belt passed through the padded case dual strap loop horizontally.

Alternatively the YongNuo SF-18 External Battery mounted on Camera Bag shoulder strap via the strap loop openings at the back of the padded case.

Carried via a Shoulder Strap

Even without the carrying case the SF-18 External Battery pack can be carried around using a camera strap or equivalent; since it sports a narrow slot on its top section, but wide enough to let a camera strap pass through.

Attached on a Light Stand

YongNuo SF-18 External Battery strapped on a light stand pole via the Velcro strap which exists on the front of its padded case. Here is shown in operation  connected to a Canon speedlite 580EX II flash in slave mode.

Closeup detail of YongNuo SF-18 External Battery strapped on thre light stand pole.

Compatible Canon Flashes

1. Speedlite 540EZ,
2. Speedlite 550EX,
3. Speedlite 580EX,
4. Speedlite 580EX II,
5. Speedlite 600EX-RT,
6. Macro Ring Lite MR-14EX,
7. Macro Ring Lite MR-14EX II and 
8. Macro Twin Lite MT-24EX

Compatible YongNuo Flashes

1. Speedlite YN500EX,
2. 2.4GHz Speedlite YN560 IV,
3. Speedlite YN600EX-RT,
4. Macro Flash YN-14EX,
5. Macro Flash YN-14M

Pros
Very low price compared to original Canon product.
Very good quality for the price.
Decreases flash charge time significantly.
Extends flash battery life.

Cons
Adds 415 gr of extra weight (with batteries and case) when carried around.
Quite bulky to be carried screwed under the camera.

Conclusion
As I had mentioned in similar situations, where the user is to choose between an original and a clone product, a professional or serious enthusiast photographer wouldn't look at cheap alternatives and really shouldn't since maximum reliability can only be assured with an original Canon product (or at least maximum accountability for any failure).
On the other hand, there is always a great market segment of enthusiasts and beginners that would like to experiment with strobes more than a spontaneous use and are not prepared to spend the sizable amount required for the original Canon product. In this respect YongNuo SF-18 External Battery Pack is a very decent quality alternative doing exactly the same job at a fraction of the cost.
For the record, I have spent a couple of years by now, with two copies of the YongNuo SF-18 battery pack without any problems so far.

I hope you found the article useful, thank you for viewing.
All Photos & Photosynths: © 2014-2015 S.C.Vlachos

Price & Availability
Prices for the YongNuo SF-18 Battery Pack vary depending on the source. That is between US$ 43.00 and 53.00 in the US or GBP 32.00 and 47.00 in the UK or EUR 43.00 and 50.00 in EU . The SF-18 is available from Amazon or from eBay.

As it has become common with products of Chinese origin, identical looking battery packs are also marketed under different brand names and prices vary, however there is no guaranty that they function the same.


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