Hi all
I do pull a lot of 18650 cells from Laptop batteries and i want to know how i can Measure its capacity
what is the simplest Tools i need to have and how i can do that ?
“Measure”, not “major” 
Apparently you can do a discharge test with a Turnigy Accucel-6
Simplest is either the Opus BT-C3100 or the Lii-260, but I recommend getting a 10A power supply for the Opus. Since the Opus has more charge and discharge current levels, it has the best potential to match the conditions and ratings listed for your battery on its data sheet.
Certain hobby chargers can be better for your batteries though, particularly those that use an extremely low current with lithium ion batteries that have very low voltage. You're also able to closely match the charging and discharging conditions listed on the data sheet for a particular rating. The problem with hobby chargers is that testing is slower because you can only do one at a time, it's more complicated because you have to wire your own harness or cradle, and results for internal resistance in particular can be very fickle depending on the quality of wires and solder joints.
The Accucell 6 was just recommended, and it used to be a very good choice. Unfortunately it looks like the most recent version has taken out the ability to calibrate and measure internal resistance, although I believe internal resistance could only be accessed by users with Cheali open source firmware. I may get one anyway just to see if the open source firmware can bring back both features. Unfortunately that open source firmware doesn't appear to have that low current feature.
thank you Suncoaster for your reply really helped me reading this posts
leaftye really thank you for exeplaning this to me so if i want to go pro i should buy Accucell 6 but i will only be able to test one cell at a time
so where is the best place to buy Accucell 6 and is it also made in China ?
An Accucell 6 might not be worth it anymore. An iCharger or iCharger clone (Thunder 0620 or Turnigy Reaktor) would be better since they do the low current start and read internal resistance. Check Hobbyking.com. They're probably all made in China.
Is there anything like the BT-C3100 that can test higher current draw? 1A is quite low for testing.
1A discharge is typical among the base level hobby chargers, and I'd be very surprised if a smart charger beats that any time soon.
thank you all for all your inputs but i still need the best solution to Measure about 70x 18650 cells and doing that one by one will be pain so is there is any faster solution ?
Buy several chargers? 
Actually, these can be operated from a single PC, 3A per channel, but they are not cheap.
http://vencon.com/index.php?page=prod_uba5
BT-C3100 does 4 at a time. You will not find a simple solution to do 70 at time.
Recently (40 days ago) bought Accucel 6 from Hobbyking and it does have calibration option. There's a Youtube video with like 2 versions of charger - one with bluish display (like mine) that does have calibration menu and greenish one without
but still Accucel 6 or even the iMAX B6-AC still can only discharge one cell per time right ?
i am just confused is it better to get a pro charger like Accucel 6 nor iMAX B6-AC and benefit from the charger methods they can do or to get the Opus BT-C3100 to have 4 cells discharge capability at once
No, you can discharge more than one at a time with a hobby charger, but it messes up the test results. Even if you did it anyway, it would be incredibly slow because both of those hobby chargers can only discharge at 1A, and would be even slower if you discharged in series with balancing.
Will you be logging these tests on your computer, yes or no?
Will you need fine control of charging and discharging current, yes or no?
If your answer is no to both of the above questions, then get the Opus.
Whatever you buy you best get going. :bigsmile:
With a hobby charger it’ll take you about a day/cell. 
It gives you other options but mostly it’s charge and discharge. If you don’t know you should go for simple.
I’d go for the Opus in your case.
ALL the small chargers use resistance to do the job. This creates heat that needs to be shed. They simply don’t have the ability shed more heat.
And in NO CASE should you get the IMAX. There are low quality fakes out there. You don’t know what you are doing > you could end up with a crappy charger.
For those of you who have the Opus BT-C3100, ia there any problem with using the “test” mode on unprotected cells to determine capacity? In the manual, under discharge mode, it says it takes Li-ion’s down to 2.8v, but doesnt specifically state it under the “test mode” heading.
Is 2.8v usually the acceptable charge to drain to and then recharge to determine overall capacity?
2.8V is probably usually okay, but some data sheets only say to take it down to 3.0V.
looks like i will go with the Opus BT-C3100 so any recommendation for the best cheap place to buy it from ? the only place i know is this Opus BT-C3100 V2.0 for US $50.99
Banggood have it for 46.99 USD but it may be v1.0:
like an iCharger fan boy? This can be had for $80 if you shop around. I do 3-4 amp discharges regularly to test feed my 4 cell lights with laptop pulls. It has good software if you are into graphing, two wire IR readings and a HUGE user base to post questions. Calibration and readouts match my better meters so no issues in the last 3 years. For balance or parallel charging its fun and a great tool. You can get way with cheaper hobby chargers but you then are at the mercy of the likes HobbyFartz and the other Chinese Triad of non support and total customer contempt. Ah, the lure of cheap stuff! If you never had a problem then your golden and life is good. They are the reason I quit cheap 6ch helicopters.
My $19 i4 has worked great during the last year, for grunt work charging, with darn near perfect termination. LOL, never seen such a hated or loved charger depending on your mileage! A volt meter and run timer is basic but works. Yuk?
That said, I really want the Opus BT-C3100 and all the informative display readout goodness. BUT, I just don’t trust them for the long haul until the price includes a better power supply or you can end up near the iCharger price for the 106B. HKJ’s charger tests are a great way to check out this charger!
Eww, hobbypartz. They really do seem to hate their customers, don't they? Even their price matching policy exudes that. I tried it before, and they took a week to get back to me, and even then they didn't accept a price match. Then they don't beat the price, they only match it, and only if the competitor has them in stock. I was tempted to try it since Hobbyking is out of stock, but of course that won't work. Even hobbypartz seems to understand that they're a vendor of last resort. Sorry, I'll happily wait for Hobbyking than try to deal with hobbypartz again.
Anyhow, since you just pushed the iCharger, I'll push the Turnigy Reaktor again. It appears to be a perfect replica of the iCharger 206B, which is a very good charger, but it sells for less than the iCharger 106B. Hobbyking is out of stock right now, but you should wait for them to restock since it doesn't seem like you're in a rush.