-
1Prepare Cells
Start by charging all the cells up to their maximum capacity. Once they're all charged you can use a multimeter to sort the cells by their voltage, trying to minimize the differential for each set of parallel cells.
Place each cell into a $1 paper coin sleeve to prevent shorting/rubbing/damage to the wrap.
-
2Connect Cells
Connect all cells in the 8 series - 4 parallel configuration using the nickle strip. Ideally use a spot welder to minimize cell damage.
The BMS re-balancing and sensor wires can be attached to the nickle strip using a soldering iron.
Appropriate wires can be connected to the positive and negative strips at each end of the pack in the same way.
-
3Wrap Pack
Use kapton tape to wrap the entire battery pack. Since the cells are inside paper coin sleeves, this shouldn't result in damage to the cell wrapping if it needs to be removed later.
The kapton tape should keep everything together and electrically isolated, but still let heat through.
-
4Connect BMS
Connect the BMS in through the negative terminals to protect the newly created pack.
I secured the BMS to the pack using... more kapton tape.
On the positive terminal attach a switch and a fuse, or if you're clever a fused-switch.
-
5Build PC
If you're reading this you probably already know how to build a PC.
If using the indicated motherboard, it is necessary to update the BIOS to at least revision 19 in order to support the APU. This can be done by formatting the smallest USB drive you can find in fat32 format, placing the BIOS binary in the top directory of the drive, and renaming it to "gigabyte.bin". Plug the drive into the white USB port closest to the board and press the button next to it. Flashing took about 2 minutes for my system.
The main change with the Pico PSU is that you will only have 4 pins of 12v instead of 8 pins, however on the selected board this is called out as appropriate in the manual if you utilize the 4 pin plug on the correct side of the 8 pin port.
It is advisable to power the PSU with a stable 12V source and ensure it's running, booting, etc before continuing.
I wrapped the bottom of my motherboard with kapton tape to keep it electrically isolated from anything below it.
-
6Shuck Kraken SDR
The Kraken comes in a lovely enclosure but there simply isn't enough room to bring all the extra aluminum along.
The enclosure is held together by several screws with hex heads. The enclosure is a bit sticky to take apart because the thermal pads inside are somewhat adhesive.
Once the top is removed, all the thermal pads need to be removed to reveal the screws holding the board to the bottom of the enclosure.
The thermal pads can be replaced back on the board, leaving the exterior side still covered by the protective plastic until you're ready to install it.
-
7Shuck PowMr Charge Controller
WARNING: DON'T DO THIS
It voids your warranty, eats your oatmeal, and is illegal in several small villages.
The charge controller is full of dangerous things like big capacitors.
That said it doesn't really fit with the enclosure, so it has to come off to fit inside. Anyways it comes apart very easily with just a few screws.
I wrapped mine in kapton tape to electrically isolate it, and swapped out the short panel cable for a longer one.
-
8Drill holes
The hard sided case needs at least 6 holes.
5 for the kraken antennae, and one for charging.
With all the major parts shucked and prepped, you can set them inside and plan out the holes. With the lid opening away from me, I placed the controller and BMS on the right side, and the kraken and PC on the left side. The controller sits on top of the bms, and the PC on top of the kraken.
The antennae holes can be marked and drilled. The XT90 port can be drilled and dremeled out on the controller side.
For the XT90, this is as good a time as any to install the bulkhead connector with some wires that will eventually hook into the charge controller.
-
9Wiring
Cut and strip wiring for:
- 24 to 12 volt DC-DC buck converter
- PC PSU
- USB C inputs
- USB C outputs
- Fans (combine all four 40mm fans into one wire, in series to maintain voltage)
I found it best to tin the ends so they don't get splayed out when put into the clamp connectors on the controllers and converters
Hook the buck converter and all the USB boards directly to the charge controller's output since they need to be fed 24V. Connect the PSU and fans to the output of the buck converter since they need 12V.
If you are using an adjustable buck board, make sure to set the voltage properly BEFORE you wire it to your expensive PC.
-
10Packing
Fit everything back inside in the same way as from the test fit. Make sure to zip tie or hotglue down wires and cables so they don't interfere with the fans.
Using adhesive to keep parts in position is also probably a good idea.
Make sure to keep the power switch off while you mess around to prevent shorting anything expensive.
Discussions
Become a Hackaday.io Member
Create an account to leave a comment. Already have an account? Log In.