I'm looking to get one or two external battery packs for my Canon 580 flashes. I already have a Quantum Turbo 3 which is awesome but expensive.
I've seen previous discussions on here and wonder if anyone has had a chance to compare the 8xAA external packs such as this (£15): http://www.ebay.co.uk/itm/External-Flash-Battery-Pack-CP-E4-8x-AA-for-Canon-580EXII-580EX-550EX-MR-14EX-/111066136775?pt=UK_CamerasPhoto_CameraAccessories_CameraFlashUnits_JN&hash=item19dc0ec0c7
with the Godox pb820 (£86): http://www.ebay.co.uk/itm/PB820-External-Flash-Power-Battery-Pack-for-Canon-550EX-580EX-II-430EZ-UK-LOCAL-/121085004256?pt=UK_CamerasPhoto_CameraAccessories_CameraFlashUnits_JN&hash=item1c313a89e0
I'm looking to use them for strobist work and they will be attached to lighting stands.
I'm interested to find out how the recharge time compares. The Godox claims to have faster recharge but if anyone can share hands-on experience of these that would be great.
The CP-E4 clones are fine (~3x quicker than just AA batteries in the flashgun in my experience), if you really need faster recycle times then perhaps a change of flash system altogether is needed (Elinchrom Ranger Quadra for example).
The quality of some of the copies are questionable though compared to the original Canon ones if you're intending to give them a hard life.
On my 550EX flashes I get ~1800+ fill flashes with them and the recycle time's astonishingly quick.
For the money you can't go wrong, and IMO they're the best type of external packs for speedlites simply because you can buy extra AAs anywhere if needed (with the likes of Quantum etc. you're buggered if you run out)