@awk Perhaps @kidsandliz can add some clarity, but I do believe that we have accomplished the rare triple burial: batteries in remote in fridge. We would have to bury the whole fridge to really get to the next level, but at that point we’d just be getting silly.
Items tested on a Keithley 2380-500-15 programmable DC load: Test 1: Unit 1 was cracked open to identify the cells and to test cells directly. Cells charged to 4.3V (per spec) maximum. Tester set up for 5W continuous power discharge, 2.9V cell cutoff.
Discharge time: 14830.3 sec.
Energy capacity: 20.598 Wh
Current capacity: 5.667 Ah = 2833mAh per cell. Test 2: Unit 3 was charged overnight via USB and discharged via USB through a 6" 20AWG cable into the tester. Tester set for 2.5W CP, 3.5V cutoff (output of the booster cuts off quickly; anything under 4V would be fine here).
Discharge time: 24545.1s
Energy capacity: 17.044 Wh
Current capacity (pack): 3.315 Ah
Current capacity (cell*): 4.604 Ah
cell capacity calculated normalized to 3.6V cell.
Note: I performed a discharge test using a decommissioned Apple 30-pin charging cable, repurposed to this test. It was about 1m long, and I estimate the wires to be about 28 or 30 AWG (really small). It introduced a significant power drain unaccounted by the test rig, so I got a plain USB plug and soldered 20AWG wires to it directly, to cut out the middle-man. Test results above are with the improved setup.
Test 3: Unit 3 charged via USB, discharged with the 20AWG cable to 2.5W CP, 3.5V cutoff.
Discharge time: 24618.3 sec.
Energy capacity: 17.096 Wh
Current capacity (pack): 3.326 Ah
Current capacity (cell*): 4.604 Ah
I may set it to discharge through the crap cable again, to get good numbers.
Note: 2.5W discharge corresponds to a 500mA (1/2 Amp) charge rate.
@PocketBrain That’s 6000 Chinese mAh. They lose about 2000mAh converting from Metric to Imperial, plus a few more after the new import tariffs. Just like flashlights… Are those Lumens, or Chinese Lumens?
But hey, at least they’re RoHS, right? (or was that just in the American product template artwork?)
Seriously though, why don’t they ever measure these damn things in Watt-hours?
@thismyusername Yes… The problem with doing the calculation yourself is you never know what the internal voltage is, and it varies greatly as things discharge. If you have 2 lithium cells in series it’s on the order of 7.2V, or 10.8V/14.4 for some of the jump starter packs, listing capacity in mAh is therefore meaningless and can’t be used as a direct comparison when judging capacity. Further, If your 3.6V lithium is using an inefficient boost supply to generate 5V, then the actual watt-hours you get from the product are significantly reduced…
You might as well weigh the product and see how heavy it is, it’ll probably be a closer approximation than the ideal estimates provided by the manufacturers. (Compare mass of an “Ultrafire 18650” cell to an actual Panasonig 18650 cell to see what I mean… )
(mAh)*(V)/1000 = (Wh)
Sort of. The cell voltage will drop from fully-charged, under load (about 4.1V) to the setpoint (2.9V is essentially drained). More reason why Ah/mAh is a meaningless metric. That’s why I include Wh; it is a meaningful metric. I should have said that up-front. I might kick off a Teardown Tuesday with this study.
Note: 2.5W discharge produced a USB voltage of about 5.1V with the short, larger gage cable and about 4.7-4.8V with the long, thin-gage cable. I imagine you would get significantly reduced capacity with a full 2.1A discharge rate either way.
One of the three coupon codes is calling. $2.50/6,000 mAh. But was already loaded up on battery banks before Meh suckered me in for a handful of those USB fan+battery bank kits in odd colors a while back. Hmmm… Decisions, decisions…
Hey, since those battery banks were single 18650’s, these banks would run the fans for hours, right?
@yeppers you might not have lost out as much as you might think unless you’re still averaging at least one Meh purchase/month. (I’m far from it.)
Depending on how you look at the Legacy VMP Casemates K-deal…
If you were contining to buy Meh deals every month anyway, it was a half off VMP (12x$60, the K-price) deal since you’d apply the 3 x $10 coupons to something you were already going to buy.
If you were not buying every month, but for some silly unexplained and irrational reason were letting that auto-VMP $5 charge hit every month then it might have looked tempting as a means to get current Meh deals back to the sweet deals of the first 12-18 launch months… with a 3 x $10 deal discount.
I’m in the latter “silly” category.
PS: BTW, if you happened to be a wine drinker who buys > $10 bottles of wine it certainly was a great way to bring the much more expensive $8-12 shipping over there down to $5/month.
I’m not and I don’t.
PPS: Note, I neglected to mention the “free” Casemates t-shirt - while it was appreciated, it wasn’t what made the Legacy VMP K-deal tempting.
@RedOak I’m more or less at the point of getting something once a month, justifying my VMP but no more than that, which is why the idea of prepaying 6 months of VMP didn’t win me over until after I read the email saying “look, effectively half price VMP if you prepay,” by which point I had missed it.
I’m not heartbroken about it. If I don’t get anything in March, I’ll probably cancel, which I couldn’t do if I had prepaid.
PS: I don’t appreciate wine, so the cheap stuff tastes almost the same as the expensive stuff to me (along with most of the US, as demonstrated in blind “Two Buck Chuck” tests [performed by statisticians, not me]).
@RedOak Sadly, my state doesn’t allow Costco to sell alcohol. I’ll stop by Total Beverage when they have sales on beer (I think I’m not snooty about it but I prefer Belgian beers when they’re not hideously expensive), G&Ts with Sapphire and Schweppes, and lately I’ve been hankering for Shipwreck rum for sipping. If my wife is with me and there’s a cheap wine that she wants to try, we’ll a bottle, but our upper bound is like $10. Actually, now that I think about it, we usually (also) get Barefoot or sometimes Jam Jar.
I’m guessing Costco’s London Dry Gin is Tanqueray 10, which a quick image search seems to bear out (green glass vs blue). Tanq 10 is also an excellent top-shelf gin, more available around here, and goes better with Canada Dry than Sapphire does. (My nearby grocery store’s private label tonic seems to be Canada Dry, and Sapphire with that or with name-brand Canada Dry is less good.)
Now you’ve got me talking about gin. This thread may never end.
@richrauch-No, the cable comes with each Power Pack & you have to plug them & As Usual <<<Notice the last 2 words, now the 1st of the last two words!! Gotcha! Just playing, I’m bored until my nurse does a Tequila run for me!! MY BAD!!
@decoratedwarvet-Sorry,I read that while upside down! You want built-in Cables. Well, I’ll bet you don’t buy a lot of Stuff!! Most of my STUFF Does NOT have built-in cables. Does your cell phone & tablet have the cables built-in?¿ That would be like running around with an extension chord attached to them!! LOL!!
@decoratedwarvet Yes, but when there are built in cables, the added convenience is helpful… At least it was with the small Energizer battery packs meh sold a while back with the built in microUSB (and lightning) cables. That was always in my bag and served me well!
At least until I switched to USB-C. I’d need an adapter which would be much easier to misplace than a short USB cable, thus totally negating the convenience factor.
I wonder where that battery pack is now? Couldn’t find it in the refrigerator – which also has a built in cable BTW.
How does this work, I got some of this earlier in the year and when the light goes off while charging the phone it stops charging unless I’m doing something wrong. At this point they’re not working for me…help