The Chinese name is actually literally God Ox. What a strong brand.
As a owner of two good old Sunpak 120J's, I always want some power pack. Even I have the original pack in form but not in substance. I use some rechargeable battery to power the pack. It's a bit cumbersome I have a separate branded charger to charge the battery and when fully charged I put it back into the holder. You probably don't know what I am talking about. I am too lazy to take any pictures.
Universal Smart Charger. Not just phone could be smart.
Not all sync cords are created equal. Some are obviously better. The one on the right is better, which is a Paramount cable by the way. The one on the left is the original Sunpak cable that has bad contact with the PC outlet on the D810 camera. Bad. I think the locking one is the best but I have yet to try one.
My SB-600 is kind of broken, the battery door has bad contacts when I don't use reputable branded batteries. I think there is some play to the battery door which can result in bad connection with some batteries. The hot shoe is cracked and the knocking pin is ruined.
And so I bought a SB-800 which is similar but better than the SB-600. It accepts external battery pack. It provides more option and plays.
I did some research and in the end, I bought the Godox PB960 pack with a cable for Nikon. The connection as I understood it is a Quantum cable connection. Though I can't find any affirmation online that the Godox PB960 can work with the Sunpak 120J I decided to give it a try. Lucky me I was able to find a Quantum CS4 cable connecting the PB960 to the 120J.
The items arrived and everything just works.
Moving on to some other distractions.
Recap: now I can power two 120J with external powerpacks which definitely provide more flashes and much faster recycle time. Or I can shoot my SB-800 using high speed sync with instantaneous recycle time, almost.
UPDATE:
7/23/2018
Something is not right when the power pack is attached to the Nikon SB-800. Initially I thought it just worked. But I guess it's iffy actually. Because the SB-800 needs 4AA even when it's supposed to be powered by the pack, so even when the SB-800 is not getting the power from the pack I wouldn't know or it wasn't obvious when the AA are in good power. Many months ago when I knew the 4AA were running low and then it became apparent that the pack was not powering the SB-800.
My feeling is it's the cable or the ProPac NX cable. I watched a YouTube video which was similar to what I experience. Though initially I thought if I power the ProPac and then the SB-800 in that particular everything would work. It does work but then it is iffy. Sometimes it works but sometimes it doesn't. I tried 1/1 manual mode so the SB-800 which uses the most power and more noticeable in the cycling time when it draws from the pack or when it draws from the 4AA. When the SB-800 actually draws power from the pack, I can see the cycling time is faster and the pack's red ready light actually goes dark for a second when it's getting ready for the SB-800. When the SB-800 is drawing power from its own 4AA (even when it's attached to the pack), the cycling time takes much longer and the ready light on the pack doesn't goes dark at all.
I am debating if I should buy a quantum cable or paramount cable or simply take a chance with another Godox ProPac NX cable. There is a possiblity that the SB-800 is the culprit but I doubt it.