The FastTech New Arrivals page has Protection Circuits up on their new arrivals page:
http://www.fasttech.com/category/1/new-products/LTI9MS0yMy0yMDEz/
5A/4A/2A for 18mm cells and 4A/2A for 16mm cells. Also some other 3-cell configs? And a charge indicator as well...
<fixed glaring redundant statement above... S) >
Just ordered the charge indicator. :)
The charge indicator’s “details” are wrong tho. It describes a protection circuit instead.
Anyone think 4.275V is a tad bit high for overcharging protection?
I wish it was 4.20-4.22V ish.
Overcharge protection shouldnt exceed 4.25v imho.
Any idea what the difference between these are?
http://www.fasttech.com/products/1/10003004/1225200-t-5016a15-8a-protective-circuit-board-for-3-cell-r
http://www.fasttech.com/products/1030/10003004/1225201-wh-4s8al-8a-protective-circuit-board-for-3-cell-re
Not sure about the leds but its interesting. 4 leds & a button for some type of status. Silkscreen for the leds don’t help at all (led1,led2,led3,led4) Can’t read the part number on the extra chip (leds connect to it). My guess would be a charge level indicator like item 1225203
You may be able to see the pictures a bit better if you open them separate. At least its a bit better on my pc. fasttechcdn.com/products/122/1225201/1225201-2.jpg
Seems to include a ntc thermistor. I would try it just for that.
Guys 4.275 volts is not to high, charging is supposed to stop between 4.15 and 4.25 volts.
Yeah, I think you’re right… a NTC for temperature cut-off… and most likely a 4 led charge indicator.
Pretty cool for the price.
Gotcha. 
nice find, I’ve been hoping they’d start carrying those, as I never completely trust DX to fulfill an order (although I did just receive a 1S PCB I ordered on the 4th Jan).
I’m not sure how these will work if you want to add one to an unprotected cell and shrink wrap it for use in a light, as there doesn’t seem to be any P- contact on the back of the board, unless I’m missing something. Also, you’ll have to find some thin metal strip to connect to B+ so that you don’t increase the diameter of the battery too much. The ones on DX have both of those features, although they’re rarely important to me as I don’t use 18650 torches - all my batteries are either in packs or built in.
Protection shouldn’t be relied upon to terminate charging, it’s just a last safety measure. It’s supposed to protect battery from exploding, not from wearing out more due to too high voltage.
I agree that PCB’s should be used to terminate charging but why not take the extra step to prevent wear and tear?
Shadowww is saying the should not be used to terminate charging. You're saying you agree but saying the opposite. 
Haha, yeah I guess.
Current PCB’s don’t, but I hope they lower the upper voltage threshold to save the cells from cheap chargers that terminate at 4.25V.
Or am I being too nit picky? 
4.25 volts is completely in spec...
Problem is: the components in cell PCBs already do exist and are being sold in quantities of millions. And those have certain specs, changing those is not worth it for the few cells being sold with PCBs.
I remember over at CPF someone’s experiment results (was it HKJ?) where he tested cycling at 4.30V and 4.40V and had drastically reduced lives.
