Home Made Leisure Battery Enclosure Help

[Digz]

Hi guys, Im hoping you can give me some much sought after help.

Over the coming summer months (and cloudy nights) Im looking to get a decent leisure battery and would quite like to make my own enclosure containing various 12V cigarette sockets for my kit.

At present I would like to be able to run my mount (NEQ6 Pro), Atik Tian, plus spare ports and even something to help me run my Mackbook - maybe some sort of power inverter?

I have seen some great threads on here with some great enclosures:

http://stargazerslounge.com/diy-astronomer/132215-cloudy-nights-make-diy-projects-power-station.html

http://stargazerslounge.com/diy-astronomer/95646-105ah-powertank.html

What I am wondering is, can someone can tell me exactly what I need to make my own. Im after what parts are needed to add the cigarette sockets and any advice on wiring etc.

Just to recap I would like to make an enclosure which will have several cigarette sockets for my mount, CCD plus spare, and a way to power my mackbook plus any other foreseeable future buts and pieces.

Any help and advice will be greatly appreciated.

PS I am an absolute newbie when it comes to wiring etc.

[Herbig]

I to am interested in this project, I'm looking to get a leisure battery and planned to make an enclosure, thinking to include 240v hook up and charging too.

Look forward to reading any ideas.

Pete

[James]

Are either of you going to SGL6? If so I'll be bringing my battery box along (It's the one thats on the second link in the opening post).

You're welcome to have a good look at it but I bought it off Arad85 when he sold his as I'm useless at making things like this...

James

[NickK]

Just a point - you need to use a pure sine wave inverter and not one that uses "modified sine wave". The annoying bit is that they're more expensive (Maplins: modified=£24, pure-sine=£109 for a 300W).

If you use a modified sine wave inverter, the power brick of the mac will make crackly noises which isn't a good sign supposedly.

I have a modified wave inverter and it works but the noise sounds like the brick is shorting inside... so I'd concur with the observation of using pure-sine wave inverters.

[Digz]

Hi James,

Thanks for the opportunity, unfortunately I cant make it to SGL6, Im hoping to make it next year though

I was hoping Arad85 might have spotted this and listed the components so I can start to source them. I have a feeling I might be equally as useless at this as well, but if someone can point me in the right direction Im a fast learner.

Nick, thanks for the heads up. Ill make sure to use a pure sine wave inverter, what ever one of those are.....*heads off to google*....

[James]

Send him a PM... I'm pretty sure he still pops in from time to time

James

[arad85]

You don't need an invertor for the macbook, just google "macbook car adapter" and you'll find a cigarette lighter version for £20-£30.

I'll reply later about parts (gotta have tea now...)

[Digz]

Arad, many thanks for chipping in

Ill google macbook car adapter and see what I come up with.

I look forward to your parts list and hope your tea was tasty

[arad85]

Umm... Maybe tomorrow peeps... Still have this on my list of things to do...

[leenewtoastro]

cigarette sockets are the clumsiest elec connection i've ever encountered imo.

and bulky

for the currents we use you could mount 8 phono's to a maplin project box for the space of 2 cig outlets!

bit of soldering jiggery pokery and roberts ya fathers brother

[arad85]

PS I am an absolute newbie when it comes to wiring etc.

First thing then : make sure you're confident of what you're doing. If you connect the thing up the wrong way around, or short the battery in any way, you have a lump of lead capable of discharging several hundred amps in a very short period of time. Broken kit and possibly damage to yourself may happen. Warning over.

Actually, wiring these things up is incredibly easy. All the connections in my box were crimp connectors (no soldering needed) and the only hard parts were deciding which connectors were needed for the battery.

My completed box is shown here: http://stargazerslounge.com/diy-astronomer/95646-105ah-powertank.html

I ended up buying:

• 6 marine 12V sockets for mounting on the lid
  
• about 6m of twin core 1.25mm2 DC power cable (15A capable)
  
• a load of female spade crimp connectors of the right cable diameter (I used 4 per 12V socket and they have red insulation - the insulation colour determines the cable thickness they will use)
  
• some crimp washer style terminals (to connect to the battery - you need 2 of the appropriate size per socket - I think mine were 8mm but it is better to buy )
  
• 6 way auto fuse box
  
• 6 blade type 10A fuses (for above fuse box).
  

Plan exactly how the box works. You have a 25kg lump of battery and the box needs to be:

• Sturdy enough to carry it about (this is particularly important for the handle). I used 9mm thick ply with a sandwiched base of 2 x 9mm ply so I could put some foam insulation in to protect the bottom of the battery from the cold ground.
  
• Small enough to be compact but still able to fit the battery
  
• Big enough to fit the lid on with the connectors and wiring in place and when it is in place you have to make sure the wires don't foul the battery
  
• Easy maintenance. You need to be able to charge the battery (I was eventually going to do it through one of the 12V connectors) AND you need to be able to get to the battery just in case you need to replace it. In my case, the 25mm dowelling handle can be pulled out completely so the battery could be removed. Also, note the finger hole in the top of my box to enable you to lift the lid easily when fitted. It also acts as an escape hole should any fumes escape.
  
• Drilling large holes in ply (for handle and 12v mounting points) can be awkward. It might be good to have a decent workbench to work on for this
  
• I would order the components you are going to use for the electrics BEFORE building the box so you can see their dimensions.
  

Start off by building your box and lid (all holes drilled) and varnish the lid with 2-3 coats of yacht varnish. I did at least 3 coats on the outside of my box, paying extra attention to the joins where the end grain is showing. Once dry, you then need to mount the 12V sockets, and fusebox on the lid.

Wiring is now pretty easy, although you do need to plan the cable runs. Assuming you get twin DC cable (one sheathed red, the other sheathed black), start off by carefully splitting it with a knife into a red coil and a black coil. Use the red for all things positive, the black for all things negative. The wiring is now very simple. The centre point of the 12V socket needs to be wired to one side of the fusebox and the other side of the fusebox to the + connector of the battery. The side contact of the 12V socket needs to be wired to the - connector of the battery.

Crimping is easy with a crimp tool (about £5 from a DIY store) and they normally include a wire stripper between the handles to allow you to strip the wire back. If you've never crimped, or not seen it done, take a look here: How to use an Electrical Crimping Tool | eHow.com and probably on youtube. Then you just methodically connect up centre 12V socket to one side of fuse, other side of fuse to + battery. Side contact to - battery.

As I said in the other post, I bought from towzatronics off e-bay. They had everything apart from the fuse box (again, search for auto fuse box and you can't go wrong). Cost was about £40-£45 all in (I bought some cable ties etc to help keep the cable tidy).

I've subscribed to this thread, so if anyone wants any more help, I should get notified.

[Digz]

Hi Arad,

Many thanks for taking the time to list out the components, its much appreciated :hello2:

As for the health warning, I hear that loud and clear. The last thing I want is to short the battery, ruin my kit or evening injure myself!

I guess I just need to carefully consider how many sockets I need and what size leisure battery to get, plus try and think of any future proofing items I might need to cater for

[Digz]

cigarette sockets are the clumsiest elec connection i've ever encountered imo.

and bulky

for the currents we use you could mount 8 phono's to a maplin project box for the space of 2 cig outlets!

bit of soldering jiggery pokery and roberts ya fathers brother

Sorry, I missed this. How does this help?

[arad85]

Sorry, I missed this. How does this help?

It doesn't really as most equipment comes with 12V car sockets attached - you'd have to get a soldering iron out. Just that you could use these (amperages allowing).

[Digz]

Ah right, I get it. Dont fancy giving that ago, recipe for a big disaster methinks

[Herbig]

Great stuff Arad85, getting the batt this week so will be getting out the tools this weekend!

Pete

[leenewtoastro]

Ah right, I get it. Dont fancy giving that ago, recipe for a big disaster methinks

on your part? the phono would be compact and more secure than cig power but as i said and others currents would need be assesed

[astroimpulse]

Using decent sockets with the right plugs allows them to be very secure.

The marine ones I bought (I think they were linked to above - Towzer) coupled with single arm plugs (I changed all of mine over as double arms are troublesome) means they lock tightly in place.

The only way they're coming out is by twisting them 90°

Nothing wrong with different solutions though.

But if you're at a field and something breaks and you need to borrow something...other astronomers will have cigar lighter based kit.

[leenewtoastro]

oh yes locking is great. we must convert those cig users:crybaby2::hello2:

[old_eyes]

See my revoltingly kludged version here.

Stuck with marine twist-lock cigar sockets as they are so widely used.

old_eyes

[astroimpulse]

oh yes locking is great. we must convert those cig users:crybaby2:

I was talking about cig sockets They just lock when you twist single arm plugs in

Cigs are the way to go because they're so widely used as old eyes has also pointed out.