Just received “8” 18650 Trustfires from CN Quality Goods in the mail. I always check the charge condition of batteries before I put them on the charger. I was shocked to find out that 4 of the batteries were in a partially charged state fresh out of their packaging….4.05-4.10 volts? I was of the assumption that Lipo’s should be stored/shipped in a resting state of 3.85 volts. Also, “1” of the batteries was reading “0” and further examination revealed that it’s low voltage protection was tripped. I was able to charge this battery and bring it back….but now concerned that CNQG sent me a bad batch. Are these batteries safe to use? I emailed Ric about a week ago and have not heard anything back.
[quote]
[What you received are rewrapped old laptop cells. Check capacity and get refund.
You can use them, but only individually, never in pairs.quote]
That’s not good!
These batteries were purchased from CNQG’s ad brand new, authentic Trustfire Flames….in shrink wrap with official hologram. From posts on “this forum”, I was lead to believe that this was a good place to buy from.
Could you elaborate.
Milan, I’m trying to understand how you determined these are laptop pulls from the information provided in the OP. All I see are varying initial charge states; something that could happen on any cells.
Typically when a cells is first formed it sits around 3.80V - 3.90V. Typically, not always.
Mike, I would keep an eye on the one that was tripped in a low voltage state. Charge it up and see if it has similar capacity to the others. If you have a hobby charger, fully charge and discharge test the total capacity of each cell so you know what you have.
I will try that on the battery that arrived displaying “0” volts. I was able to charge it to 4.2v with my Icharger 3010B. The cells are advertised as 3000 mah. I guess I will discharge at 1A and take it down to around 3.7v. My question is…… I really don’t know how many mAh I am expecting to see.
3v when doing a discharge test is fine. The battery will sag under a load. The more you load it (current) the greater the voltage sag. So when the charger stops at 3v under the load. The battery, once rested for 10 minutes or so should bounce back to around 3.4v or so. Perfectly acceptable for li-ions. The newer Panasonics can be discharged down to 2.5v under a load. So it also depends on the battery being discharged. Li-ions are considered dead at around 3.4v or so when measured at rest (does depend on battery). So if a light drawing 3 amps stops working because the low voltage protection kicks in from either the battery or driver, the battery isn’t actually at 3v at rest. Once its allowed to rest the voltage will be much higher than the protections trip voltage.
Try here, going down to about the middle of the thread under HKJ’s table’s.
