12v power box completed!

[niko]

Apart from possibly the worst choice of colour (baby sick green) I'm really pleased with having finally finished this box.

Two 55AH batteries give me 110AH charging from a 20W solar panel and leading to 4 x cig socket outlets.

It should give me about 5 hours running scope mount, camera battery pack, dew heaters and laptop - even more without the dew heaters as they draw 7 amps per channel.

I'm yet to test how long it runs for - just glad to get it all together. Need to tidy up the cabling a bit but all seems to work as the photos atest.

I think I may have underestimated (or overestimated) the panels ability to quickly recharge the batteries - seems to be taking days and days. I may end up adding another panel.

Anyway, pleased that my back-of-the-envelope sketch became a reality.

cheers

niko

[bahoogas]

Nice work. I think the colour is the best bit!

[OICURMT]

You should author this in the DIY section with a parts list and instructions.

I would imagine many of us would love to build something similar (sans the paint job ... :lol: )

OIC!
BTW: Great stuff!

[noswonky]

Can't beat green power!

[Allan_L]

Very Cool Niko,
Good work. :thumbsup:
I am going to try something similar myself.
Probably heavy though, right?

Recharge - yes, I had similar issues with my recharging my campervan's house batteries.
OK lets analyse - 20 watt solar cell (@12 volts = 1.6amps max)
forgetting efficiency losses (usually around 20%) to recharge 110 amp hours of battery power (depending on state of discharge) could take you up to 69 hours. (110 / 1.6).

Probably a 60watt solar cell may be the go.
Keep us informed of how it works out, please! :thanx:

regards
Allan

[niko]

thanks everyone

Green power! I hadn't thought of that one. LOL! :lol:

Alan - the weight is 45kgs - 20 kgs each for the batteries and 5kg for the box - I had to put aluminium channel around the edges to strengthen it. I planned to use a little fold away Bunnings trolley to move it around if they have that carrying capacity - otherwise a regular trolley will have to do - mount the panel above it.I'm annoyed I didn't do the sums on the recharge - 69 hours is ridiculous so will have to increase the panel size which defeats the cheapness of the setup somewhat.

Oh - I heard that gell batteries require a special recharger and that lead acid ones (ie cheapies) won't work. Is that REALLY true?

cheers

niko

[RB]

Hey well done niko, great job.
I built something similar a few years back, I called it "The Hot Seat".
You can read about it in this thread. (http://www.iceinspace.com.au/forum/showthread.php?t=8150&highlight=hot+box)

I used a 12v deep cycle battery and an inverter that doubles up as a seat.

I've taken it along to many astro camps and works like a charm.

:)

[Marke]

Yes its true some require different charge rates and voltages depends on battery but AGM often need 14.7v as apposed to 14.4 for charging
compared to a wet cell .

[mithrandir]

My only observation would be that cigarette plugs/sockets aren't particularly reliable, unless you like the way they pull apart when someone trips over the cable.

Some Anderson (http://andersonpower.com.au/store/index.php?main_page=index) connectors might be a good move and have greater current capacity and less resistance.

[Poita]

Yes, Gel cels require a specific charger, a Lead Acid battery charger will kill them I believe.