Whenever an unknown supplier pops up, we do some basics. We check for a physical address. We do a reverse look-up on the phone number. Look for a business license in the area? In the case of JOYFAY, the results speak for themselves. There is often an ES member who lives in the area of a questionable supplier. Sometimes they drop by the business and ask some questions.
In your search you may come across a giant battery scam which was conducted from Lacey, WA.
http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=18583&p=274292&hilit=+lacey%2C+wa.+#p274292
They had the lowest price LiFePo4 cells by about 10%. Many ES members lost all their money on this one. When asked for a physical address, they declined. This was enough for some of us to take our business elsewhere. Close call for me.
Perhaps you could start a new thread with the fact you are looking for a 48V pack with BMS? Searching for something specific is sometimes very challenging on ES. Be patient, there are a ton of experienced people here, and they are very responsive. Most have jobs, and don't monitor ES all day.
It can be very informative, to just spend some time blindly browsing the many forums. Get a feel for what is where.
Edit;
Read some more on LIPO using a BMS. The BMS fails and you have a little fire on your hands. I think you will find most LIPO users', balance once a week or once a month because, they don't enjoy the little fires? Lipo reminds me of a magnesium flare dropped in a rubber liferaft, which had 6" of water in it.
Oh no, we have a hole in the raft.
BUT THE FLARE IS GONE
Edit;
And another newbee gets bit in the ass with a bargain. Made in USA.
http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=33939
Come on fellows, take some friendly advice and quit thinking you are the greatest bargain hunters on the planet. Buy from a know source, who will support you and save your agony.