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 (James)]

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 ... )

OIC!
BTW: Great stuff!

[noswonky (Peter)]

Can't beat green power!

[Allan_L (Allan)]

Very Cool Niko,
Good work.
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!

regards
Allan

Originally Posted by 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

[niko]

thanks everyone

Green power! I hadn't thought of that one. 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 (Andrew)]

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.

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 (Mark)]

Originally Posted by niko

thanks everyone


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

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 (Andrew)]

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 connectors might be a good move and have greater current capacity and less resistance.

[Poita (Peter)]

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

Originally Posted by niko

thanks everyone

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