# Search results

1. ### SkyRC — IFA 2014 — MC3000 charger-analyzer

Or apparently a rectangular block labeled MC3000 moving around the screen with a ball bouncing around off the edges and the moving block as well. Yes, I agree. If you're on grid the charging efficiency is a who cares. If you're off grid working out of a backpack with a small solar panel and...
2. ### USB powered 4xAA (independent) analyzing charger

How it their math? Xiaomi says it has 10Ah capacity. It likely does at the voltage of the internal batteries. It could have 10Ah of NiMH batteries in parallel at 1.2V or 10Ah of SLA at 12V. You're measuring the mAh of a 5V output. The output voltage is different from the internal battery...
3. ### USB powered 4xAA (independent) analyzing charger

I think your math is off. That's 10Ah at ~3.7V, so 37Wh. 6.25Ah at 5V = 31.25Wh. Basically 84.5% efficient to the USB output.
4. ### SkyRC — IFA 2014 — MC3000 charger-analyzer

Has anyone measured the charging efficiency of the MC3000 in terms of Whr consumed to x Whr put in the batteries? Like a AA Eneloop has about 2.4Wh. So, if you're charging 4 of them with the MC3000, at say C/2 per battery, how many Whr does the charger use to put 9.6Whr into the 4 batteries...
5. ### USB powered 4xAA (independent) analyzing charger

So the more I look into this the worse and worse it looks. The Li-Ion power banks are only 80% efficient when charging, they're only about 80% efficient when outputting their power to USB. NiMH chargers are less than 50% efficient. My BC-700 looks to be about 40% efficient at transferring...
6. ### USB powered 4xAA (independent) analyzing charger

So it turns out the BC-700 takes 3V on the input, not 12V. Further, the wall wart the comes with it is only rated for 2.8A. I'm going to test and see how much current the BC-700 actually draws while charging 4 AA Eneloop batteries, but a decent buck converter should be able to make 3V @ 2.8A...
7. ### USB powered 4xAA (independent) analyzing charger

I have something more like that in mind for home, but with higher wattage panels. Trying to see about a MPPT instead of a PWM controller, but I don't think the low cost ones actually are true MPPTs. However, here I want something I can stuff in a backpack and leave with if needed. It uses...
8. ### SkyRC — IFA 2014 — MC3000 charger-analyzer

Why can't it just turn off the LCD like a normal charger and act like it's off? There were no batteries in it.
9. ### USB powered 4xAA (independent) analyzing charger

The idea was to use a 5V solar panel like this to charge a Li-Ion power bank which could then charge AA batteries or other devices that connect to USB to charge. Well, I don't really need an analyzing charger per say. I want to see roughly how much energy is going into the batteries. I do...
10. ### USB powered 4xAA (independent) analyzing charger

I'm looking for a 4xAA/AAA analyzing charger that can be powered via USB (5V). Independent channels are a must and the ability to put >500mA per channel into a battery. I also want a LCD that shows mAh, time, etc. Does anything like this exist? Something like a LaCrosse BC-700/900 or Opus...
11. ### SkyRC — IFA 2014 — MC3000 charger-analyzer

So I came home from work yesterday to find my MC3000 playing "Pong" on the LCD with the backlight on and making beeping noises as the ball bounced around. Why on earth would someone program a charger that's plugged into the wall but without batteries in it to do that? I pressed a few buttons...
12. ### While studying multimeters found this

The mics and monitor packs I'm talking about use AA's, not 9Vs. How long does an Alkaleak 9V last in one? if a 250mAh NiMH can't last 90 minutes, a Alkaleak shouldn't last much if any longer unless they just don't like the lower voltage.
13. ### While studying multimeters found this

Why not a battery tester instead of multimeter? I've seen rechargeable NiMH batteries used in the wireless mic and monitor packs. Charge after every performance or day if there are multiple performances a day. Once a month run a conditioning cycle on them.
14. ### While studying multimeters found this

That can't be done without shortening the integration time which is rarely beneficial. If you want to catch transients, a meter is not the right tool. An old analog meter still has inductance in the coil swinging the needle and mechanical inertia, so it's not like they're a panacea.
15. ### While studying multimeters found this

It sounds like you want a modern digital oscilloscope.
16. ### While studying multimeters found this

Not really, it means it has a NIST traceable calibration certificate included with it. Meaning it's they're certifying the calibration back to some NIST calibrated device. IMHO, the Uni-Trend UT-61E is pretty much all the multimeter someone tinkering around needs.
17. ### SkyRC — IFA 2014 — MC3000 charger-analyzer

I just got one from GB with US plug and it had FW 1.10 on it out of the box.
18. ### Finally! A \$20 USB logging luxmeter

Well 2000 data points isn't sufficient for any of the logging I've been doing at 1 sample per second. I use it tethered to the PC and let the software record the data.
19. ### Finally! A \$20 USB logging luxmeter

Good luck. Their software only works with a specific driver that doesn't work in any OS newer than XP or XP x64. With your own app or script it may be possible to use it with only the generic USB to serial driver.
20. ### Finally! A \$20 USB logging luxmeter

There's one left on eBay for \$27.86 shipped if you're in the US.