I decided to run some comparison tests between the XTAR 2600 and Solarforce 2400 since I have them readily available. I'm using the XTAR WPA 2 II charger. Both cells charge to ~4.15V. The three flashlights used are the Trustfire X9, L2P with the UF 3-mode XM-L T6 (UF) and the L2T with a 1-mode U2 from KD (U2). DMM used is the Equus 3220.
XTAR 2600
X9 1.70A
UF 3.05A
U2 1.65A
Solarforce 2400
X9 1.785A (+5%)
UF 3.20A (+5%)
U2 1.82A (+10%)
I was under the impression the XTAR's would drive these lights a bit harder, but it looks like I'm getting more out of the Solarforce cells. I assume the XTAR's will give me longer run time, but I don't understand the lower output. I don't take these numbers as gospel, but I'll use the differences as a reference. Is this normal?
And here is a rub , readings can vary [ a lot ] if you dont take measurements from the exact same place on the light ..
You would be amazed at the difference , say from the sweet spot to the bad spot , [ locations you place you MM probe... ]
The other variable could be emitter temperature , a lot of emitters when they get to the right temp can pull more current ,
Same with the batteries , 5 deg C can make a difference ..
Its like , why does my light only pull 2.5A [ cool day ] and then another day it pulls 3.2A [ warm day ] , there are lots of variables , which is why Current draw , output , should be considered a rough guide , and if your going to measure , then you need to test where you take measurements from , for consistency of results .
Oh I agree. I actually did several tests, recharge, test again. The numbers weren't always exactly the same but the results I posted are a good representation. I really go to town touching the probe on the threads and find good contact. I have a good idea by now about what reading I'll get depending on where I put it. I'll do a couple more runs tomorrow. After I do one cell I'll let the lights cool for a while and then I'll move on to the next cell. I'll charge and then do another run. I really don't put a lot of stock in any single reading. Like you say, it's more of a guide. I just take all the results and compare them to each other for reference.
No, i get slightly higher amps from my Solarforce 2400s also. For eg, in my DRY.
I mentioned that in the DRY thread. I Also told scheven_architect that it does not mean the XTAR 2600 are bad (and made SA repeat that himself). It's just a "characteristic".
I like the charger but maybe I don't need to go gaga over the batteries. They perform well but I still have a use for batteries that will drive some of my lights as hard as the driver will allow. I was just a bit surprised is all.
Well no worries on that little diff. Usually for 99% of the lights out there esp the more "direct-drive" ones, they don't make a difference on the lux meter. Unless if yours is a really heavily and excellent heatsinked one like Yezl M7X. For the regulated single 18650s like RRT-2, they don't make any difference.
Yes, like old4570 said, there are variables like temperature etc. But generally for me I get somewhat slightly higher discharge amps from the Solarforce 2400. That said, Sanyo 2600 is king, even better than my Panasonic 2900/3100.
But in the real world, no appreciable difference or advantage in usage between all those batteries i have mentioned as far as current draw is concerned. All are capable stuff...
Oh yeah, I goofed on the XTAR posting. The UF and U2 results should be swapped. They should be fixed now.
I hope that didn't cause any confusion. The point was the Solarforce batteries consistently pulled about 5% to 10% more than the XTAR batteries, rather than seeing erratic amperage readings.