Voltlog #42 – DIY 4 x 18650 Battery Charger

Today we’re going to be making a DIY lithium battery charger and more specifically aimed at charging 18650 cells. I sometimes take apart some of these laptop batteries to recover 18650 cells and I have a bunch so far that I kept. Every-time I salvage these cells I test them before deciding to keep them or not.

As you can imagine it takes time and I need to charge multiple cells at once. So I will be making a charger that can handle 4 x 18650 cells but the project is scalable and you can increase or decrease the number of cells it can handle according to your needs. As usual, links for all the items will be in the video description.

Voltlog #41 – 60W Dummy Load Mod 20mA to 999mA

This video is about the 60W dummy load discussed in episode number #38 and #39 and if you haven’t watched those two videos I recommend you do, there will be links below. In this video I am doing a mod to change the range of the dummy load from 0.2A-9.99A to a new range of 20mA to 999mA.

Voltlog #40 – InTheMail

Once again too many mail items to fit into a single video, so we have a two parts upload. In the first video I only had time to show two items the SONOFF from ITead and the SP mini from Broadlink but that is including teardowns and discussions on the internals.  Surprisingly the SP mini doesn’t use the ESP8266 as expected but instead it uses the MT7681 from MediaTek.

Voltlog #39 – 60W Dummy Load Reverse Engineering

In this video we’re discussing the dummy load again but this time I reverse engineered the dummy load schematic and I discuss it’s basic theory of operation. Check the video description for a link to the pdf schematic.

Voltlog #38 – 60W Dummy Load Review

In this video I am doing a review of the recently purchased 60W Electronic Dummy Load. I go through the different operating modes, a short stress thermal test and in the end I am presenting a conclusion whether or not this is a good buy.

Voltlog #37 – InTheMail

Hi and welcome to a new InTheMail, this time we have allot of items to look at and some of them were ordered 2 or even 3 months ago but due to the postal service madness that happens every year during holidays they arrived a bit late.

The video is split across two parts to avoid making it too long so make sure you watch both parts.

Voltlog #36 – The Dark Load PCB Layout With EagleCAD

This video is mostly a time-lapse of me doing the PCB layout for the Dark Load project that I am working on. However during the first minutes of the video I am commenting and giving some hints on some design decisions that I make during layout.

This entire design is open source and it will be shared once I have it working but for now it’s still quite beta and I don’t want to release something that is potentially not working or might contain errors.

Voltlog #35 – SMD Assembly And Reflow

In this video I am going to show you how I assemble PCBs with surface mount devices. First I apply the solder paste with the help of a stainless steel laser cut stencil, next I manually pick and place all the components and the last step is to run the boards through a reflow profile in my DIY reflow oven.

Voltlog #34 – Fluke 77 Teardown & Repair, Varistor Replacement

In this video I’m opening the Fluke 77 I scored at a recent auction to show and repair a small issue it has. One of the MOV (metal oxide varistor) in the input protection circuit had suffered damage probably while protecting the rest of the circuit when a HV signal was applied to it’s input, so I decided to replace the MOV.

The original MOV part number is V910LSX1399 specs: 910V 10% 1mA
The replacement MOV part number is Panasonic ERZV10D911 specs 910V 1mA

Voltlog #33 – Ublox 7 GPS USB to UART Conversion Hack

In this video I am hacking this vk-172 cheap usb gps module to use UART instead of USB. The module contains the ublox 7 chipset which is quite nice and it makes it much more useful having an UART interface.

PIO10 > pin 33 controls the hardware pin remapping feature
PIO10 low = UART remapped to PIO15 > pin 36 and PIO16 > pin 37
PIO10 high = UART on standard TX on PIO6 > pin 19 and RX on PIO7 > pin 18