Building a new diy power box

[Epicyclus Dave]

Hi all

I've been busy with the saw last weekend in the shed and some off cuts of ply & a paint brush .

To house my new 90AH 12v AGM battery (alpha batt own brand) , i have knocked together a 400mm L / 330mm W / 300mm H , plywood box with foil back sheet insulation on bottom & sides and foam sheet for the lid .

I've made room for a control / charge panel inside and a wee space for my mount power lead storage.

A pic of the box with 6 12v marine sockets , each wired with 2.5mm sq stranded cable ready to plug into the fuse bank .

And a side elevation cross section of the battery area diagram .

Hope to get some more stuff done over the weekend.

Dave.

[Jessun]

Nice work! 90AH should take you through the night!

I myself have only bad experience with cig plug type sockets, but perhaps the marine ones provide a solid connection.

[Epicyclus Dave]

Thanks Jesper , i got some lock plugs for these sockets , twist to release type , should do the trick .

Dave

[Epicyclus Dave]

Hi there.

almost finished , got the controls wired up at the weekend & tested with a multimeter before connecting the brass clamps to the battery terminals.

I slightly underestimated the weight 18Kg , nevermind , i'll just have to have 3 wheat-a-bix before carrying it out to the car heh .

At the control panel i have a big square red on/off DP switch, + and - wired from the battery with 6mm sq cooker cable ,

to the separate switch poles, the switch in "off" position couples the charge socket to the battery , the "on" position isolates the charge socket and supplies the fuse bank still with 6mm cable , .

The circular red switch is for turning on an led dimmer pcb, the control dial is just out of pic, for my (still to build) battery snug belt , which will warm the air gap between the insulation & battery , really an extra long dew strip.

Circuits 1 to 4 are the first 4 marine sockets protected with 5A blade fuses , for mount / laptop etc..

Circuit 5 a marine socket with 10A fuse.

Circuit 6 a marine socket with 20A fuse (12V hair drier for bad dew ).

Circuit 7 battery warm / dimmer circuit protected with 3A fuse.

I was going to build another battery low led / transistor circuit but i spotted one of those cheap plug in cigar type, 7 segment volt reader displays.

Dave.

[knobby]

Really nice job !

Sent from my HTC One X using Tapatalk 2

[Epicyclus Dave]

Thanks Knobby , taken a while to build but im really pleased with it .

[Epicyclus Dave]

Hi there .

First test was friday night (28th) and all seems good .

I carried out a temp. test for my snug belt on the battery , after 3 hrs outside sitting on gravel , with the long diy heat band on med temp setting which is velcro'd round the battery, it maintained 19C inside the batt. chamber while it was 6C outside, magic , i suppose the real test will be in January at the cold minus numbers , heh .

I also tried my cheap 12V plug in volt meter from fleabay and it's not quite the same reading as a bench meter (about 0.5V out) i'll see if it comes apart to find a trimmer inside , saying that i should really take a multimeter with me to remote sites, always handy .

Loading up the power box with Neq6 / laptop(12v charg) / 5 Dew heaters (scope, finder, eyepiece, 2 dslrs doing tmelapse on tripods) / battery warm belt , the constant current draw was 4 to 4.5 Amps , the battery is a 12V 90Ah AGM now working at room temp. outside , half the rated battery capacity for prefered 50% discharge = 45Ah = 10 hours constant 4.5A draw , more than enough for 2 typical nights after work. Fab

Dave.

[cjdawson]

Looks like I'm raising the dead on an old post here

So, it's three years on from when you made this battery box.  How's it worked out in the long run?

I've just finished making my own battery box out of a plastic toolbox.  Although, I didn't put any insulation into the system, I'm now looking at this and wondering if I can add some.  Should be easy enough to fit to mine.   How does your box work in the winter?   Is there any changes that you'd make to your setup to improve the life of the battery?  or anything else for that matter?

[Epicyclus Dave]

Heh   there is always useful information hiding in old threads , old threads are great .

The power box is still going strong, no issues with power on outings, and stable in freezing conditions,.....  fingers crossed for another few years use from the AGM battery , I keep it happy with a multi stage Ring charger  RSC512   http://www.ringautomotive.co.uk/uk/products/Cars/Battery+Care/SmartCharge-plus-/RSC512  .

If you can get your hands on some off cuts of Kingspan or cellotex expanded foil lined foam wall sheet from a builders skip, they are great insulators , if not give your battery a jacket of itchy loft rockwool  

Dave.

[cjdawson]

I"m going to buy a sheet of 25mm thick as I'm thinking about making a second battery box, so that I can double the capacity. £20 for a sheet isn't too bad.