The protection circuit is used for more than lo-voltage cutoff - it also cuts current in the event of a dead-short.
The working current limit is also a PCB variable not mentioned here. There is little use for a PCB that allows no more than a 1.5A current draw, for example, with an XM-L.
Having been self employed for years, I can't forget paying the bills.
I think we have to remember the manufacturer is in this for a profit. There seems to be fewer buyers than builders need to make it worthwhile to bring these "logical" products to market.
When was the last time you went to your job and worked for free?
The one I posted from DX has a review where a guy tested it drawing 4 amps. I would say that is sufficient for my lights.
here are my measurements, I can say, this is a decent pcb:
low voltage cut off ~ 2.505V
high voltage cut off ~ 4.36V
max current ~ 7.5A
low voltage cut off
high voltage cut off, the battery is disconnected until the charging voltage is above the cell self voltage,
I tried it 5 times
max current, when the load has been disconnected, the battery is back
That is awesome, thanks for the info! Out of curiosity, would that low of a cut off voltage render the battery unsafe afterwards, or does the battery come back up after resting?
I have one or two circuits removed from Solarforce cells - would you like them?
Sure! PM sent.
@viffer750 - what s/w is that? Also, can it handle two simultaneous inputs (e.g. 1st DMM for V and 2nd for Current)? USB support?
THX!
EDIT: Ah sorry, I just did a search and found this:
http://home.comcast.net/~wisdomcc/roastgraphing/roastgraphing.htm
And @OP - sorry for going OT
No problem, I was wondering the same thing about the software anyways, thanks for the link.
Thanks to viffer I'm going to order a couple circuits for protecting 26650s!
I mostly want low voltage cutoff as they'll be a gift...(I'm too paranoid to wait for circuit to kick in)
though, obviously, tripping at too low of a current would be bad. guess it isn't a problem for these. too bad these are from DX...at least her birthday is in May.
anyway - I have 25ft of ebay pvc shrink (black) for doing sub-cs and I'm scrapping that project, so I'll only need a foot or two for myself. I *think* it will fit on 26650s. If anybody wants some, pm me.
No need to solder the minus to the battery i.m.o.
Just put the minus tab between battery and shrinktube.
More than enough mm² contact surface.
However, might any electrolytic phenomenon happen to ruin the fun, I’ll let you all know a.s.a.p. 
O, and I solder the plus tab on the plus, no extra teet needed.
All in all some 2.5mm added to the length of the battery.
Insulation for plus tab with one layer of kapton tape.
Also insulated the bottom, in case of cracking the PCB, not possible to short.
Superglued the prot. circuit in place before soldering the plus tab.
I used shrink PVC for 18650 on 14500 batteries, which I do not recommend.
FT has 14500 size shrinktube though.
Bit of a necro post.
But I’ll join in anyway. Seiko protection pcb on aliexpress. I was just searching awhile ago to see how available quality seiko protection was. Also comes in a 20 pack for a lower price each. Battery wire strips are available on ebay.
Necropost as in poking a (presumed) dead topic?
I came across it, and thought it could use some updating.
BTW, how do you connect the minus tabs?
These are 4A per cell protection circuits
http://www.fasttech.com/products/1616/10003003/1225103-wh-18650a-4a-protective-circuit-board-for-18650-re
$1.49 for a 2 pack
protection circuit for 3x 18650’s in a pack
http://www.fasttech.com/products/1030/10003004/1225200
$4.48
The protection ICs they use are cheap. If your adding protection get seiko.
I not really a fan of heating the bottom. I try to avoid it. I know some use a high wattage iron & do it very fast before much heat can spread. Might be fine. If soldering I might go for low temp solder & do it on a chilled battery.
http://www.fasttech.com/product/1477405
$1.02 for one 14500 pcb…
It has the tabs already on it though.
Just 2A, but who would want to draw more from a 14500 anyway?
It may not hold in court, but I see the same PCBs on both FT’s and Ali’s links
Aliexpress/Fasttech = walmart, alibaba/dhgate = SAMS
Walmart is retail=individually wrapped, SAMS is wholesale=bulk lots
same critter…don’t believe for a second that ALL of these places aren’t buying HUGE lots from the wholesalers and just reselling them
I dropped a FT Panasonic 18650 and damaged the protection circuit. I got the ones from DX and soldered it on. Works fine.
Same board but the chips are different.
Evva vs. Keeppower NCR18650B Protection
Seiko is regarded to be top quality. The chips often used on cheap protection is of unknown quality. No hard data on their quality. Personally I suspect they are junk compared to seiko.