Been lookin’ for a deal on these for a while; got um TY.
I bought these 3 for $14.99 they have a switch instead of button the switch is off, on and movement sensor that turns off after 20 seconds. I find them easier to use for old folks.
What is that and where did that thing come from? I guess I didn’t read the deal :person_facepalming:
I don’t have a vipon account, what’s the coupon code please?
X7NPGMTR
X7NPGMTR Mr. Slider ! I just bought these!
thanks!!
I have some under a different brand name. Like the light, but the battery is short lived in high use areas. That seems to be common in lights this size and design, whether LiOn powered or AAA. Just not much juice available.
I use them for places where you don’t use them much, like the pantry and towel cabinet, the pantry light gets recharged once a month when I start noticing the light not being bright enough. the towel cabinet about every 2 months. Not bad IMO.
WARNING!
Of the 8 packs I tore down, 1 of them contained dead cells measuring around 0.5V
Attempting to recharge lithium cells that have been stored with voltage this low is a safety hazard and must be recycled. Hopefully everyone checks the voltage of their cells before putting them into service.
The rest of the cells measured around 3.25 –3.29V and are just fine.
Too bad the deal is dead of Id buy more.
I took apart the 2 packs I got yesterday and all measured around 3.25 to 3.3 volts. I also looked at getting more packs a couple of days ago but as you said the deal is dead.
I also wished I had bought more and I’ll have to check BatteryHobby periodically to see if they have other deals in the future.
Great that you’re checking your voltages and staying safe. Lets hope everyone else has done the same. Its best not to sit on these packs before tearing them down, since I suspect the BMS has some level of parasitic drain and the cells are already well below storage voltage.
On my Opus 3100 the first set of capacity tests at 1A yielded 3002mAh, 2923mAh, 3010mAh, and 2985mAh. The 30Q datasheet states that the minimum capacity is 2950mAh but that’s at a discharge of 0.2C and a cutoff at 2.5 volts. Given that I was discharging at 1A and that the Opus terminated earlier I’d say that the batteries were in good shape.
Luckily you found that 0.5 volt battery. As you mentioned it’s wise to check all batteries when delivered, even new ones from stores. I’m pretty anal about safety checks on things that are potentially life threatening. Better to be overly careful rather than not is how I see things. 
Good for you! Given the parameters you mentioned, your cells appear to be performing above spec.
Optimally, I prefer to recharge 20 or more cells at the same time from a matching set. Then test voltages to assure they terminated properly. After the cells have rested a day or 2, I group them by voltage down to the nearest 0.01V and use cells of the same voltage in serial celled lights. And the reason for all this anal laborious BS? In high current lights after a full run, a bad cell in a series configuration usually reads much lower voltage than the rest. This may have occurred through increased IR or the cell was damaged during high discharge. So it is removed, marked and then relegated to 1S lights. Ive been surprised more than a few times how many new cells proved to under-perform and how quickly they can die unexpectedly at any time while being abused during high discharge. Name brand cells can usually tolerate a lot more abuse before catastrophic failure and many data sheets show their limits. But those limits are proven under controlled laboratory conditions in open air and not while contained inside an aluminum tube with other hot cells and a hot flashlight head cooking them.
There was a forum member I used to trade with. His father owned a company that subcontracted for Sony testing failed lithium cells. They have 3 scanning electron microscopes, among other very expensive high tech equipment. I concluded that their function was to provide forensic analysis of battery failures to indemnify Sony from the cell manufacturer during potential litigation. Its interesting to note that most catastrophic cell failures go unreported, never hit the media or mentioned online, and they occur dozens of times every day across the globe in a device somewhere. I wish I knew what percentage occur in trusted name brand electronics versus the mountain of rubbish being sold to people desperate to save a buck. Ironic how this comes up in this thread! :laughing:
It wasnt just one cell that measured 0.5V, it was all the cells in the entire pack. I suspect a defect in the BMS which caused a slow voltage leak. Since the cells are aprox 3 years old, you can bet they have been resting at that voltage for some time and I wouldn’t dare try to charge them. Even if they held a charge, they could still reverse and become unstable at any time in the future.
Ahhhh ok, the entire pack was bad rather than just 1 battery. Yeah it makes sense that they were drained by the BMS. I’ve had tool pack batteries drained to ~0 volts and that was probably related to the BMS.
I can see doing all that work for batteries that are going to be used in series. I don’t have any series lights, nor do I plan to, so my testing is much more limited. Do you charge all the batteries from the same charger, and at the same time? If batteries are being charged in a multi-slot charger how do you account for differences in the slots? Most if not all of my multi-slot chargers don’t charge to the same level. Are you charging them in series parallel so that their voltages equalizes?
Edited to change series to parallel
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https://www.bestbuy.com/site/best-buy-essentials-350-lumen-led-flashlight-black/6459555.p?skuId=6459555 - $4.99 with free shipping
out of the ten packs i got, my range was 3.19 to 3.39. so no bms bleed down on my end.
The bms is produced by blueway, and they hold a bunch of patents for (lion) bms… Its not as simple as a resistor between the third pin (com) and another pin. To my very untrained eye, there is a sister board to enable/disable charging. Now i didnt purchase these for the bms it just wouldve been super useful for a couple projects if i couldve made them easily work.
Also noticed that the 5 pin pad on top of the bms is NOT covered in conformal coating (nor is the bottom containing test pads)…. and the pin layout is something i swear ive seen tearing apart UPS (battery backup) . [clock, data, ground, 3.3v, voltage peak to peak]. VPP seem to run to pin 1 of the microcontroller labeled 3z41s1 1811 651. Which seems to be a clone chip with no data sheet. I dont have a ton of free time right now so this is where i stopped before i tore them all apart… im sure it wont help anyone but i felt the need to comment with identifying marks (forgive errors, the eyes are getting old).
Identifying marks:
tti-6s1p-pcm-b
blueway
3z41s1 1811 651
v85501b
ru 94v8
e348968 xc02
bd76925 7btg4 c4l3
For 18650, 26650 and 32650 I use a bank of 5 reliable 4 station chargers, which terminate consistently at 4.20V. They are the older Soshine S1-max V3.0 and well reviewed by HKJ. They are true 4 amp chargers with fixed 1A per station. I purchased a case of them, which may be why all the chargers are matched in performance. Now I wish I never sold the rest. I cant speak for their quality or availability now, especially since the overall build quality in many cheap consumer electronics has slipped in recent years. I own several chargers and most dont terminate with 100% consistency over the course of dozens of charge cycles… the S1-max has proven reliable and always does. The only thing I can add is I always used a cool dry basement for recharging, which helps keep cells and chargers from overheating. Cells are stored in the basement at storage voltage and I bring them upstairs to warm up for a few hours before charging.
I guess the quality control on the Soshine’s are, or was, pretty good to have them match up so well. Since they probably came from the same lot that likely helps too.
I corrected my early post to say “Are you charging them in parallel so that their voltages equalizes”. That was bad typing on my part to say series since parallel charging is the way to match them up, at least until they’re off the charger.
No worries. Im hopeful to spread the word to everyone to invest in a digital multi-meter and how to monitor their cells to minimize the chances of a fire or explosion. This thread seems appropriate, given the type of abysmal merch that is often listed here.