Month: September 2017

O’CELL 26650 LiFePO4 8S 3.3Ah battery pack with BMS (WHL #28)

Same thing again – but different manufacturer. That’s what you get when you clean up your new lab… ;)

I know, might be boring to see another battery pack with almost identical specs (3.3Ah instead of 3.2Ah), but trust me, this is like night and day – or like quality China and Wan Hung Lo.

Of course these two batteries were purchased at the same time for the same thing, and they cost around the same as well. But (spoiler!): These two units work fine.

Top view:

Nice shrink wrap, proper label (shout out to O’CELL and their caring but not nagging sales people). […]

24th September 2017 3rd October 2017 By Bzzz In 2 Comments

CY UC-022-0.9M USB 3.1 Type-C Female to USB 2.0 A Male Cable (90cm) (Rant #R1)

Oooh, look at that precious hellspawn!

“USB-C to USB 2.0 Data Cable for Macbook Tablet, Mobile Phone – Black” – capturing everything that is wrong with USB-C!

Sure, carrying over the perfectly fine USB 3.0 spec into USB 3.1 and calling it “Gen 1” (in contrast to “USB 3.1 Gen 2” that is double the speed) is a huge fuckup on its own. There’s no better way to screw up a customer by allowing manufacturers to call something USB 3.1 compliant (new! shiny!) when it’s just 3.0 with a new badge. […]

16th September 2017 11th September 2017 By Bzzz In No Comment

26650 LiFePO4 8S battery pack with BMS (WHL #27)

This weeks article is another by-product of the ADC testing (WHL #26) from last week. Could’ve packed in there, but I wanted to share some remarks on Chinese battery technology…

So first of all, this isn’t a piece of kit that I bought myself. After testing two 12V/2.2Ah lead batteries from work that were sitting unused on a shelf for five years, I needed another victim. Those quality Panasonic cells were flat as Kansas – the LC-R122R2PG datasheets recommends 8.6V cutoff voltage at 3C = 6.6A or 9.7V at 1C. Fully charged, they delivered 1C at 7V or 1.5C at 2.5V at full charge – slow 10.5V discharging to 0.1C cutoff and recharging didn’t help much. […]

10th September 2017 10th September 2017 By Bzzz In No Comment

16 Bit I2C ADS1115 Module ADC 4 channel with Pro Gain Amplifier RPi (WHL #26)

Meep. We finally have a new product review, after all that editorial, recap and electronic load rubbish ;)

Today’s item in the mail is an I²C ADC on a small PCB, running four channels (or two differential ones) with 16 bit precision. Sounds nice? Well, if it holds the claimed specs, it IS a nice product! I bought it in mid-June on AliExpress for 2.06 USD. Adafruit, by the way, charges 15 bucks for the exact same thing. Do I smell profit margin?

Here’s how it looks straight out of the ESD bag:

Backside is a tad boring (keep the VDD in mind):

(there’s a floating island on the GND plane, boo!) […]

3rd September 2017 3rd September 2017 By Bzzz In 1 Comment