Yesterday my Ultrafire C3 ss arrived. Like it allot but must say the finishing and material could be better. But to an inexpirience eye it is a nice product
So i was trying different NiMH battery cells (found out that alkaline are no good) . I also tried different brands of NiMH and saw that the Energizer NH15 are the best batteries i have.
I looked up their datasheets and i found that Energizers have a lower impedance even to the eneloop Sanyo do. Because i don't have any eneloop does someone know this as a fact?That the Energizer brand can output higher currents cause of their lower impedance?
Don
- 2010.01.31
- 03:31:55
http://www.cheapbatterypacks.com
The current depends - the LED only needs so much - for a 3W LED with a forward voltage of 3V you need an amp from the cell - assuming 100% efficiency of the driver which does not happen. The ability to deliver more is not really relevant with LEDs as with the exception of the SST50/90 emitters no LED needs much more than 3A at (say) 4V or 12W neglecting driver losses. Good NiMH AAs are good for at least 5-10A. Eneloops start to sag in voltage at about 8A. A lower impedance cell won't sag in voltage till a higher current. I have some NiMH Sub-C's that will hold 1.2V at 30A. But unless you are building a battery pack for an SST90 LED you don't need that sort of output. This is more of an issue with high-powered incandescent bulbs where the runtime may be only a few minutes. A 12V 100W bulb needs 8 and a bit amps from 10 cells. However, fully charged cells are in the 1.4-1.5V range and most incandescent bulbs will take a greater or lesser amount of over-voltage which makes them brighter though shorter lived. Some won't and blow immediately. With a 12V250W bulb you are pulling more than 20A from the cells and you need the lowest impedance cells you can get. these tend to be lower capacity.
But for LED use, Eneloops are the best bet just now.
jayki
danton
- 2010.01.31
- 21:41:35
Yes i have the 98mm long and it has a memory mode
I am nt sure what is ment by memory mode so let me explain how it works
If the flashlight is on high and you turn it off and on it will tun on high again
If the flashlight is in any other mode and you turn it off and on it will turn on to the next mode it was before
Is this a memory mode??
Something else i see that you have to clasp the battery cap really good so there won't be any contact issues.Might be that my battery is a little short in length but not such a problem
Vectrex
- 2010.02.01
- 10:07:36
The question is: Do you like the lights anyway? If you say it is still OK, I wouldn't bother getting a refund, because it is much work.
Your complaint (with photos of the DX-envelope and exact photo of what is wrong with the light).... 4-5 workdays later answer from DX ("Did you look in the forums?") ... your answer (" Yes I looked in the forums and it is definitely a different light than advertised - with link to the thread ")... 4-5 workdays later answer from DX ("would you like a replacement or refund or store credit?")...... It feels like taking forever but in the end you might get a store credit to buy an other flashlight with other faults ;-) With the whole communication it has taken me about 3 weeks to get a replacement for my defective C78, that's without the shipping time. Don't get me wrong I still love DX and the service is excellent, but it is slooow and they have a certain procedure to ask you everything obvious. If you stay calm, polite and relaxed you can come to an agreement. (like paying for one and getting one for free for example)
If you still want to complain, here is where you start: http://services.dealextreme.com/ . I hope you still have the original envelope?
Vectrex
- 2010.02.01
- 10:28:57
BTW I would take a store credit and buy an other light. Sending it back was no option for me, because shipping cost would have exceeded the value of the light multiple times (Europe/Germany). Exchanging the lights is also difficult, you might end up with the same version you have now, because the "old" version is no longer produced. Try to get a good deal like I said above (like paying for one and getting one for free (store credit) for example) and buy a nice Romisen (maybe a G2 ?) or an other proven manufacturer who doesn't change the designs so often. (Ultrafire is just the worst... you never know what you gonna get... design-wise ... quality-wise)
danton
- 2010.02.01
- 20:12:50
I am going to stick with this one.It is not that bad. I want to modify it anyway. I didn't know you have to keep the envelope.I threw it away once i opened it.
From what i understand from a Cree technical file the Q5,P4 are only symbols that define the brightness. I can't say for sure that the 2 wire one is only P4 or lower.
Something else.I ordered another light without tracking number. The first one came in 6 days. I don't know why but everything comes quickly to me. Its about 12 days for the second one.What happens if it doesn't arrive?
Vectrex
- 2010.02.01
- 23:07:34
P2<P3<P4<Q2<Q3<Q4<Q5<R2<R4<R5<S2... ??? is just the classification in brightness called "binning"
http://www.abload.de/img/fluxxb0ag8.jpg
XR-C<XR-E<XP-E<XP-G is the Emitter type from CREE (beam angle, efficiency, max amps, square-mm ....)
You are right it is hard without the right equipment to tell the difference between binnings. But P4's and above have at least 3 wires. Most (or all? not sure) Q5's have 4 wires.
Start reading this and that . I had delivery times between 8 days and 5 weeks, so don't worry for at least 14 more days, after that you can start writing a ticket. http://services.dealextreme.com/
Probably. But....
They will self-discharge faster than the Eneloops. If you are regularly replacing batteries, say, weekly then the Energisers will be better. If not, the Eneloops will be better as they'll have more charge in them so will be able to provide higher current. You can get even lower impedance cells designed for radio control that will happily provide tens of amps in an AA size, but they are designed to be used hot off the charger and fully drained almost immediately.
Really depends how you use them