Sometimes I get embarrassed by some of the topics I post and this is one of them, so please could someone explain the difference between a 501 and a 502 light, and next could you also tell which would be a better host as I ordered and received a XML2-U2 drop in orange peel module
from lightmalls and would like to try and start an easy build on which ever the forum members believes would be best thanks.
But wait theres more.
http://www.manafont.com/product_info.php/ultrafire-wf504b-flashlight-tube-no-led-emitter-p-4049
You will still find slight variations off each depending on the supplier. There all P60 style lights.
Okay.but my question is what is the difference between the w501b and w 502b I seriously don’t know what the difference between the two?
There are also the a, b, c, d..... Varieties... Not sure if they all have all the different letters and not sure how high the letters go...
It's just styling differences. Some claim some are better. They are all cheap hosts. The a, b, c... Determine the cell configurations. A = cr123a/18350, b = 18650.....
501bs and 502's are pretty lame .
I've said it 100 times don't go search them out ..As a flashaholic they will just naturally come to you .
A Solarforce L2M or L2 ..or the cheapest solarforce is 5 times better than any of the commonly knocked off ultrafires ..about the only reason to have bought them was they came in like 5 colors ..but you have to be really bored to be buying colors or caught a really cool deal on them . Save your self the headache and avoid them unless you need another beater light.
top one is a 502b and bottom is a 501b
502 has a cheapo clip on it some people like ..but it's not a reason to buy it
The hosts are only worth about 5~8$ max and for about $13 you can get a solarforce which will blow it away as far as quailty.
Any good reason why ? Its a P60 host so it really depend of the module. I love my 502b and its around bright as my XinTD C8 but with more flood.
Solarforce is really ugly to me and I don’t care about the better build quality since its both made of full metal and not plastic, the side clip does all the difference for me.
Okay whi h do you think would be better as a host for my lightmalls xml2-u2 dropin?
if u really want to get an ultrafire, then get the 504b, it’s basically a solarforce L2.
i own a solarforce L2i, ultrafire 504b and 502b. i recommend solarforce as well. the machining is more precise, and it has better switch.
also, solarforce has more accessories like filters, clip, different heads and switches, etc.
but solarforce is a bit more expensive. if u are just looking for a beater light, then get the cheapest host u can find.
also, 502 over 501, coz at lease the clip is somewhat useful.
a solarforce... but if you are convinced to get a 501b, 502b.... whatever 50x*, get the one you think looks best
Ill look into thae solar forces 504 thanks again for.advice I kknow its basic knowledge for most , thanks again all
For what it’s worth, the main problem I’ve had with the 501b and 502b is it’s heatsinking. P60 hosts are prone to having poor thermal management in general, but all my 501 and 502b hosts have way too much space around where the drop in goes, meaning that an excessive amount of foil or thermal tape has to be used around the pill. It’s also with mentioning that the water resistance of my 501 and 502b hosts isn’t too good either, as the threads are pretty sloppy and the o-rings are a bit on the thin side (not that it’s an issue with me as I don’t dunk my lights), but I wouldn’t rate them as being any more than rain resistant.
I'm personally a fan of the 501 host. My first serious LED flashlight was an Ultrafire WF-501b with the XR-E R2 dropin and I still use that light regularly. As stated, heatsinking is not great but for low-powered drop-ins (<1A), I've found that they work well. One problem you will encounter is that the switches on the budget hosts tend to be flaky and not function well. A bag of replacement switches is cheap though and the replacements tend to be more reliable. One difference between the 502x and the 501/503/504 hosts is that the 502x uses a different tailcap design with a different and less common switch.
My favorite of these hosts is the 504b as it is designed better with less free space in the head. This means less foil-wrapping on the pill, so better heat sinking. It also has a definite anti-roll hex around the head and a recessed switch boot so it can tailstand. Also, no crenelations on the bezel!
50xA = 1x CR123A/16340/18350 cell
50xB = 2x CR123A/1X 18650 cell
50xC = 3x CR123A cell (or 2x AA-sized cells with a sleeve around the cells to hold them in place)
50xD = 4x CR123A cell or 2x 18650 cell (make sure your driver/drop-in can handle the higher voltage!)
This 504 B Looks different than the ones I purchased years ago.....
No reason to live with poor heat management on any P60, it's an easy fix: https://budgetlightforum.com/t/-/18148#comment-381865
I LIKE 501-b’s. They’re small and compact, cost next to nothing and NONE - NOT ONE (of at least six) has ever given me a moments trouble. I bought a couple of spare switches based on criticisms I heard here, and have never had reason to use one. The only Solar Force I ever bought lasted less than two batteries before the switch crapped out, and it ate o-rings like they were Smarties.
I wrap copper tape around the drop-in to a snug fit, add a little thermal grease, and run ’em like they were rented. XM-Ls at 3 amps - no worries. If one ever did crap out, I’d toss it and grab another one. They’re about the price of jelly beans, for crying out loud.
Buy a couple. Make up your own mind, for less than $20. 
I’m not sold on Solarforces either. The Solarforce L2 and L2P I have are too long and the light changes modes when you shake it, so I never use them. The 502B is a little heavier than a 501B and has a clip. I like the look and feel of the 502B more, but I have a couple of 501B’s and they have grown on me (one is blue, which I like, and I baked the other to a reddish copper that I also really like). The 502B head is roomier, which means you have to put more stuff in there for heatsinking. The lens in the 501B seems a little smaller than the standard P60 lens, so I haven’t been able to swap out a coated lens. I swapped out the tail switch covers on the 501B’s as well because the originals were too thin.
Don't use 'stuff'. Use a solid spacer. It works better and you don't have to use a pry bar and a bench vise to change dropins.
But I think which ever one I get will revolve around the 3.7 volt 18650 batteries since that is mainly what I have my next question where do I get thermal tape and compound to help fit the dropin fit and dissipate heat?