DIY 10ah 4s LifePo4 without a BMS V1.1

DIY 10ah 4s LifePo4 without a BMS V1.1

I had been toying with the idea of more power - either for longer operations or more power or even more devices which such as portable digital operations.

I could have gone the simple Zippy 8400mah blue brick that seems the next step up from my 4200 or.. there is the homebrew route.

Using headway 38120 lifepo 4 cells that are used in E-bikes, and some simple balance extension leads I made Big Bertha v1. 10AH 13.2v. This version does not have a Battery Management System (BMS) and for all intents and purposes, it is seen by balance chargers and even the little cell monitoring beepers that many use, like a big 4s pack.

Photo captions:

8486 - a partially built 4 cell pack comparing size with a 4200 zippy
8532 - I might have snapped up another 2x 4 cell lot on ebay that a company was getting rid of. The orange holders snap together giving the cells rigitiy
8577 - sitting on the bench testing connection to the balance charger - I took extension leads, clipped the socket end off and soldered ring terminals to the ends and connected to the negative of each cell, with one being positive - just the same as the zippy packs
8578 - v1 covered in packing foam, covered in light head shrink bags (x3)
8580 - testing my other balance charger to confirm 12v charging.

Possible improvements - increase the current handling of the load/charging cable for possible QRO operation of the 857.

Coming versions might will likely have a BMS going forward to auto cut off on low voltage.

Shopping list:

Cells, cell holders, bus bars : https://www.evworks.com.au/

The rest was either junk box or ebay

PortablePi - A RaspberryPi for Amateur radio Portable Operators

This project might be of interest to some SOTA operators.

I wanted to see if I could make a field companion Raspberry Pi for Data modes - I would never lug my laptop into the bush.

Hardware:

  • raspberry pi 3 with inbuilt wifi chip
  • USB GPS dongle
  • USB sound card
  • ZLP USB radio interface

Capability:

  • WSJT-X on RC1.9 for FT8 etc
  • Fldigi
  • Winlink using PAT - telnet only at this stage
  • APRS via Xastir and Direwolf
  • Logging using CQRLog - issues with database - working on that
  • GPS updates onboard time - needed for Data modes and logging as well as GPS for APRS

How do you use it?
Well when the Pi is near a wifi network it knows it connects when it is not - say on your favourite summit - it creates a hotspot allowing headless control by any VNC device - tablet, phone etc.

Some pictures:

Set on top of my 817

Set on top of my 817

Connected over VNC

Connected over VNC

Update: June 2018: http://wadeabout.com/blog/update-from-my-initial-testing-of-using-a-raspberry-pi-3-as-a-portable-option-for-amateur-radio-digital-modes

 

Wade
VK1MIC