Instruction: Answer the given question using the supporting document.

Input:
Question: Has anyone tried moutning this on the bottom of the body with the tripod socket?
Document: This is a function of that flash not having an external power socket, not any fault of this power pack. I am adding this note so that photogs who own that flash won't mistakenly purchase this in hopes of extending their flash battery life.
So long as you recharge it before the start of the event, I don't see anyone running one completely dead under normal usage.Generally, this pack is going to be most useful if you do rapid flash discharges at higher power. When using lower power discharges at higher ISO, you might as well leave it in the camera bag.
Like it so much that I ended up buying another after getting the first one. No more waiting for my flash, i get the shot without waiting. Carry extra batteries. Cause when the batteries run out.. they're out. My batteries last twice as long. I highly recommend this product to anyone who depends a lot on there flash.
I ordered 2 of the CP-E4 and and very happy on there performance. It has reduced the flash recycle time by 5 to 6 seconds and almost double the battery life. It is durable and lite. I like that I am able to mount it to the bottom of my camera and not have it attached to my hip, it takes come getting use to but it works out fine.
Nice option for those who don't use a battery grip on their DSLR though.The CP-E4 uses a slide-out magazine tray. Unlock it, pop it out, and add/remove the batteries as needed. Easier said than done, and the clips inside the magazine are known to easily break off (tip: use the hole on the bottom of the magazine to pop the batteries out to prevent the clips from breaking).
I've had the CP-E4 for a couple years now, and use it every time I go out. It adds that extra bit of power to the 580EXII to get you through the day (or shoot, as the case may be)It's a neat little item - an external battery pack that you keep by your side (it has a belt-loop on the carrier) and plugs into the high-voltage socket on your 580EXII (the little part covered in rubber on the side of the flash).
Both of which are considered very important. Weight of the unit isn't too bad (depends on your definition I guess) - keep in mind it's holding 8 AA Batteries though.In addition to the belt loop, you can take the CP-E4 out of its case and connect it to the tripod mount of the flash. I found this to be very odd as it's longer than most (all?) Canon DSLR Batteries.
this works as it is supposed to; it keeps the flash on the camera going longer. I use it with the 550ex with my canon 50D, 10D, 5D. There is no carrying strap, so i just made a strap, and i can carry it over my shoulder
this can let the flash get more fast to repower or rechager to the flash and can make the flash working much more longer time.
it's a bit of a ripoff. If you're a pro though, it's probably worth it to have a spare tray ready to go at a moments notice.One thing to note (I made the mistake when ordering mine alongside a 580EXII) is that it still needs 4AA in the 580EXII to operate (so you need 4 + 8 batteries - 12 total.
Answer: No, I usually use the strap[on pack] and some gaffers tape and attach it to my camera strap when I am shooting weddings.