Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
The orange curve is the last surviving (“least dead”) Wasabi battery from the 2017-08 batch and the dark green curve just above it is another DOT-01 from 2019-02. The problem is not so much their reduced capacity, but their grossly reduced voltage-under-load that triggers a premature camera shutdown.
The Batmax batteries measure better than the craptastic Wasabi batteries, worse than the STK batteries, and should survive the next year of riding. As before, I have zero belief that Amazon would send me a “genuine” Sony NP-BX1 battery, even at six times the nominal price, nor that it would perform six times better.
Batmax is one of many randomly named Amazon Marketplace sellers offering seemingly identical NP-BX1 batteries: Newmowa, Miady, Powerextra, Pickle Power, LP, Enegon, and so forth. Mysteriously, it’s always cheaper to get a handful of batteries and a charger, rather than just the batteries, so I now have a two-socket USB charger:
Batmax NP-BX1 – USB dual charger
Despite the “5 V 2 A – 10 W” and “4.2 V 0.6 A – 5 W” label on the back, charging a pair of batteries after a ride started at 700 mA from a USB 3.0 port. The charger makes no claims about USB 3 compliance, so I’d expect it to top out around 1 A from a generously specified port.
Eight minutes later, we’re turning onto the Dutchess County Rail Trail:
Losing the Battery Bag – flight – 2019-02-25
And then it’s gone:
Losing the Battery Bag – gone – 2019-02-25
Mary drove past there on her way to a distant meeting, but the little red bag was not to be found anywhere. Maybe it’ll reappear on a fence post or taped to the bulletin board; I’ve tried to return things I’ve found that way.
I expect somebody got a nice present and, if naught else, it’s good to drop happiness into the world.
There’s another reader and a quartet of batteries on their way.
Beaver Lodge – DCRT N of Golds Gym – 2016 CIR image
We went back the next day and stopped at the culvert. Their dam spans the entire near side of the pond, upstream of the ditch (just above my hand) leading to the culvert:
Beaver Lodge and Dam – DCRT N of Golds Gym – 2020-02-25
The helmet camera pictures look west from the rail trail, with the lodge in the northernmost open area. The wide-angle camera lens exaggerates the distance, but the lodge is only about 35 feet from the fence.
A stand of birch trees near the lodge now looks like a combination buffet and construction yard. When beaversdiscoverferrocement, their structures will become much more obvious.
In those 29 calendar months (maybe 20 riding months) I’ve ridden 4500-ish miles at perhaps 12 mph, so call it 375 hr = 22.5 k min. The camera fills a 4 GB file every 22.75 min, so it’s recorded 1000 files = 4 TB, which is 62× its capacity. This is better than the defunct Sandisk Extreme Pro card (3 TB & 50×) and much much better than the Sony cards (1 TB & 15×), although I have caught the camera in RCVR mode maybe twice, which means the card or camera occasionally coughs and reformats itself.
The SJCam M20 rear camera also uses a Sandisk 32 GB high-endurance card and has worked fine since early 2018. An external battery eliminated all the hassle of its feeble internal batteries, although the one that’s been in there has faded to the point of just barely keeping the clock ticking over during winter weeks without rides:
SJCAM M20 Mount – Tour Easy side view
All in all, paying the premium for video-rated MicroSD cards has been worthwhile!
Along with the (defunct) Blackburn Flea, the bike pack also disgorged an anonymous taillight with a battery resistant to recharging through the USB port. Gentle suasion cracked the solvent-glued joint around the case:
Bike taillight – cracking case
As with most modern electronics, a battery occupies most of the interior volume:
Bike taillight – opening case
For posterity, the connections:
Bike taillight – connections
I unsoldered the cell and charged it from a bench supply:
Bike taillight – external recharge
The voltage started out low with the current held to about 100 mA, eventually rose to 4.1 V, and stayed there while the current dropped to zero. Unlike the Blackburn cell, it appears not too much worse for the experience, although I haven’t measured the actual capacity.
Clipping the Tek current probe around the LED supply wire produced this waveform for the “dim” setting:
Anonymous Taillight – Low – 200 mA-div
Adding a voltage probe across the LEDs and clicking to the “high” setting:
Anonymous Taillight – High – 200 mA-div
The intense ringing at the start of the pulse seems an artifact of the measurement setup, but ya never know; these days, RFI can come from anywhere.
In any event, the COB LED strip draws 800 mA from a fully charged battery, about 26 mA for each of the 30 LEDs. The 5% duty cycle in the “dim” setting is decently bright and 18% in “high” is entire adequate.
A trio of blinks works for daytime rides, although the fastest one seems seizure-inducing.
I’ve strapped it around a rack strut and run it at the slowest blink, on the principle you can never have too many blinky lights …
It’s the green one, over on the left, pulled out of the heatstink tubing that should have provided some strain relief, having broken at the solder joint to the resistor.
A quick & easy fix, after which I reapplied even more tape to hold everything in place.
The Smell of Molten Projects in the Morning 