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DC-DC charger issues and powerbox improvements

April 30, 2020 — BarryK

Ha ha, I am an inveterate tinkerer -- in the sense of always wanting to experiment, modify and improve whatever I have designed and constructed. In fact, the journey is often as much or more fun than the destination. Camping, for example -- preparing for camping is as much fun as actually going camping.

Nice sunny day, so this morning took the powerbox outside and connected the Atem Power "250W" solar panel. Yes, it does charge, but there are two serious issues. I have sent an email to iTECHWORLD technical support, and will await their response before deciding if these "issues" can be described as faults. Stay tuned for developments.

The previous blog post for this powerbox project:

https://bkhome.org/news/202004/installation-of-the-coulometer-lcd-display.html

In earlier posts, I have identified some limitations in the physical design of the powerbox and the wiring layout. Decided to fix them,,,

Getting at those battery terminals is just too awkward and dangerous. The top-plate of the box is screwed on from the underneath. In retrospect, this was dumb, but there was a reason originally -- wanted to place the DC-DC charger flat on the top of the box, without protruding screws getting in the way.

Screwing from the top allows the screws to be removed and top panel lifted off. This allows access to the battery terminals. So, I pulled off all of the side panels, removed the screws holding on the top panel:

img1

...yay, easy access to the battery terminals. You can't see the positive terminal in the photo, as it is covered with black electrical tape.

Late night right now, tomorrow will apply screws from the top. It will be easy to remove them and lift up the top panel any time it is desired to access the battery terminals, or anything else.

Another problem is that extra terminal block just floating there, looking messy, see this earlier snapshot:

img2

Another task for tomorrow will be replacement of that floating terminal block with a small busbar mounted on the spare space on the wiring-board. And a bit of a tidy-up of the wiring. 

EDIT 2020-05-02:
The top plate has been modified, with screws on the top, so that it can be opened up. I have edited the original blog post:

https://bkhome.org/news/202004/top-plate-of-lithium-powerbox.html

To get rid of that floating terminal block, I have installed "protected +bus", using one of the 8-way busbars from Jaycar, though (currently) only need three ways:

img4

"+bus" is connected directly to the battery positive terminal, whereas "protected +bus" is on the other side of a 30A circuit breaker. Or rather, is, once it is wired up:

img5

And, after screwing the front and back panels into place:

img6

That is better. It is still crowded of course, but that was part of the exercise, to build a very compact powerbox.   

Tags: nomad