110Ah Leisure Battery Box

[kirkster501]

Sharing a few pics of my battery box I built from a 110Ah leisure battery and a very strong tool box.  I used metal XLR connectors and plugs and the whole thing can be isolated internally with a master 100A switch and 40A fuse feeding the whole thing.  Also a power meter with an internal shunt to measure power consumption.  CTEK charger point built in.

A lot more expensive to make than I would have thought - the thick end of £300.  The battery alone with delivery was £110.  The heavy duty tool box £40.  The power meter £16, the master switch £20, master fuse £10.  Power distribution fuseways with busbar £24. 16AWG and 8 AWF wire and heatshrink.  The XLR sockets are £3.80 each, same for the plugs.

I took great care to make sure the cabling was neat and tidy.  Each output individually fused as well as thee master fuse to the whole box.

The whole thing works brilliantly.

Edited November 18, 2019 by kirkster501

[tomato]

 Very smart, not cheap but very well engineered.

[Skyline]

What did you use to cut the holes in the plastic box if you don't mind me asking?

N.

[Brian28]

Hi Stephen . Nice build .. I was thinking of similar for my setup with the same type of battery 110 ah .. can you tell me how long yours lasts please ..  

[Bamo]

this is looking so cool Stephen. Trying to build the same setup. got a battery of 60 Ah. 

Possible to share the wiring diagram with us?

[kirkster501]

Sorry to miss the posts, will reply over the weekend.

[kirkster501]

On 23/11/2019 at 23:53, tomato said:

 Very smart, not cheap but very well engineered.

No not cheap at all but worth it in the end.  Doesn't matter how great your camera, scope etc is, it needs power....!

On 25/11/2019 at 22:58, Brian28 said:

Hi Stephen . Nice build .. I was thinking of similar for my setup with the same type of battery 110 ah .. can you tell me how long yours lasts please ..  

I was powering my NEQ6 mount, G2-8300 camera, laptop, guidecam, 2 x dew heaters, motorfocus (i.e. a lot of stuff) and I'd get about 2 x 12 hour sessions from it over the winter (or more, shorter sessions) before the voltage dropped down to about 21.5v.  Generally I charge it after every use.

On 24/11/2019 at 19:54, Skyline said:

What did you use to cut the holes in the plastic box if you don't mind me asking?

N.

https://www.amazon.co.uk/Surplex-Drill-Titanium-Coated-Metals/dp/B07DF744DM/ref=sr_1_1_sspa?dchild=1&keywords=3PCS+HSS+Step+Bits%2C+High+Speed+Steel+Step+Drill+Bits+Set+-+(4-12mm%2C+4-20mm+and+4-32+mm)+Cone+Drill+Bits+Hole+Cutter+for+Wood%2C+Stainless+Steel%2C+Sheet+Metal+by+SS+SHOVAN&qid=1589638862&s=diy&sr=1-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEyTFFDSUM2QldNS0RRJmVuY3J5cHRlZElkPUEwOTk2OTMwQ0tQTzVGNDBRV1NFJmVuY3J5cHRlZEFkSWQ9QTAzMDU4MzIzUE1YVlZJUlNMR1NaJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

These bits.  Very useful.  I've subsequently used them for many things.  I did not include the cost of these in the £300 I quoted above.

On 10/05/2020 at 18:19, Bamo said:

this is looking so cool Stephen. Trying to build the same setup. got a battery of 60 Ah. 

Possible to share the wiring diagram with us?

I will draw up the digram and share it.  It is very simple however. 

I will make a video of the box and share it on YouTube since some others have asked me about this battery box as well.

Edited May 20, 2020 by kirkster501
spelling

[symmetal]

Very neat construction. Nice to see you using XLR connectors. 

I note that you have wired +12V to pin 1 and Gnd to pin 3. The convention with XLR connectors is that Gnd or Screen  is wired to pin 1. If you look into the front of the socket the  metal connection on pin 1 is slightly further forward than on the other pins. This means when connecting the plug the Gnd pin connection is made before the other pins. As 3 pole XLR connectors are usually used for balanced audio connections this avoids any momentary buzzing or hum when plugging in live equipment.

When connecting power it's best that the Gnd connection is made before the other voltages to avoid momentary floating power rails. With your wiring arrangement the +12V connects before the Gnd. This probably won't cause any real issues but it's preferable to use standard wiring practice. Note there is a tag sticking up next to pin 1 on the solder side which can be bent over to solder to pin 1 to earth the shell of the connector if desired.

Being even more pedantic   4-pole XLR are usually used for DC power, with 3-pole XLRs reserved for audio connections to avoid any identification issues when connecting cable wiring looms. Using 4-pole XLRs for 12V, pin 1 is Gnd and pin 4 is +12V.

In the past 4-pole XLRs were wired with pin 1 Gnd, pin 2 +12V, pin 3 +24V and pin 4 +48V. This was to provide separate power rails for sound desk indicator bulbs and microphone phantom power but nowadays these other voltages are easily generated within the unit themselves if needed. Hand held TV cameras also use the 4-pole XLR for 12V power with +12V on pin 4.

Rant over 

Alan

 

[tomato]

@Tomatobro made a power box for our leisure battery and inverter  using more traditional materials. It’s ready for our local dark site but alas will now have to wait for the return of Astro darkness, or a proper end to the lockdown, whichever comes sooner.

 

[kirkster501]

@symmetalyes true Alan.  I became aware of that doing soem reading a few months ago (as you do!).  However, I have not yet had a problem with the current pin arrangement and I don't want to have to take the XLR's apart and redo everything, it is all neat and heat shrinked in.  If at some point I should need to do so then I will repin it.

What I will tell you guys is that this box (battery) is ***HEAVY*** !

[kirkster501]

I have looked at building an inverter into my box too but I am looking for a 12v flats panel to remove the need to do so.  My current flats panel is the only thing that needs a mains input.

[tomato]

+1 on the weight comment, they might have handles but you wouldn’t want to carry them very far...🥵

[tomato]

13 minutes ago, kirkster501 said:

I have looked at building an inverter into my box too but I am looking for a 12v flats panel to remove the need to do so.  My current flats panel is the only thing that needs a mains input.

Yes, all the gear is  5v or 12v except for the laptop, which currently is still needed for the portable imaging set up.

[Jkulin]

4 hours ago, kirkster501 said:

I have looked at building an inverter into my box too but I am looking for a 12v flats panel to remove the need to do so.  My current flats panel is the only thing that needs a mains input.

Hi Steve, I have a similar one for larger flats and the 12" version for my Esprits: -

Voilamart A2 Light Box Drawing 12V LED Tracing Board with 3 Level Brightness Ultra-Thin Artist Copy Board Micro Artcraft Animation Light Drawing Pad

More information: https://www.amazon.co.uk/dp/B07VK2GLWV/ref=cm_sw_em_r_mt_dp_U_C2gWEbMMWWJMR

[kirkster501]

18 hours ago, tomato said:

Yes, all the gear is  5v or 12v except for the laptop, which currently is still needed for the portable imaging set up.

My laptop has an adapter that allows it to be powered from 12v

14 hours ago, Jkulin said:

Hi Steve, I have a similar one for larger flats and the 12" version for my Esprits: -

Voilamart A2 Light Box Drawing 12V LED Tracing Board with 3 Level Brightness Ultra-Thin Artist Copy Board Micro Artcraft Animation Light Drawing Pad

More information: https://www.amazon.co.uk/dp/B07VK2GLWV/ref=cm_sw_em_r_mt_dp_U_C2gWEbMMWWJMR

Thanks John I will look into that  

[wookie1965]

On 16/05/2020 at 16:33, symmetal said:

Very neat construction. Nice to see you using XLR connectors. 

I note that you have wired +12V to pin 1 and Gnd to pin 3. The convention with XLR connectors is that Gnd or Screen  is wired to pin 1. If you look into the front of the socket the  metal connection on pin 1 is slightly further forward than on the other pins. This means when connecting the plug the Gnd pin connection is made before the other pins. As 3 pole XLR connectors are usually used for balanced audio connections this avoids any momentary buzzing or hum when plugging in live equipment.

When connecting power it's best that the Gnd connection is made before the other voltages to avoid momentary floating power rails. With your wiring arrangement the +12V connects before the Gnd. This probably won't cause any real issues but it's preferable to use standard wiring practice. Note there is a tag sticking up next to pin 1 on the solder side which can be bent over to solder to pin 1 to earth the shell of the connector if desired.

Being even more pedantic   4-pole XLR are usually used for DC power, with 3-pole XLRs reserved for audio connections to avoid any identification issues when connecting cable wiring looms. Using 4-pole XLRs for 12V, pin 1 is Gnd and pin 4 is +12V.

In the past 4-pole XLRs were wired with pin 1 Gnd, pin 2 +12V, pin 3 +24V and pin 4 +48V. This was to provide separate power rails for sound desk indicator bulbs and microphone phantom power but nowadays these other voltages are easily generated within the unit themselves if needed. Hand held TV cameras also use the 4-pole XLR for 12V power with +12V on pin 4.

Rant over 

Alan

 

Hi just a quick question I have made a battery box with cigarette lighter connectors I would like to change them to the XLR, s but as the mount is tip positive how do I attach these so I don't fry the board. 

[symmetal]

As long as all your XLR connectors are wired with +12V and 0V on the same pins you won't have any trouble. It's just if you swapped equipment with someone else who had wired them differently that problems can occur. kirkster501 in the first post used a 'non-standard' wiring convention but it doesn't matter as all the XLR connectors were wired the same.

If you're going to install new XLR connectors from scratch then it's best to follow XLR convention and make pin 1 Ground or 0V (or the battery negative if the whole thing is  floating). It's best to have the negative power rail connected to ground near the supply especially if you are using cheaper switch mode power supplies which only have 2 pin mains connectors without earth.

If you want to follow the 'professional' code you would use 4 pole XLR connectors and then connect the +12V to pin 4, leaving pins 2 and 3 unconnected.

You can instead use 3 pole XLR connectors as many here do, and then wire 0V to pin 1, as standard and +12V to the furthest away pin which is pin 2. Note that 3 pole and 4 pole XLRs have the pin numbers in a different order. In my reply to kirkster 501 I said he had used pins 1 and 3 on his XLRs but he had in fact used pins 1 and 2. 😉

Hope that helps wookie. 😀

Alan

Edited September 22, 2020 by symmetal

[kirkster501]

I've made a few minor tweaks to the box and will post some updated pics later.

I agree Alan with your important comment, you should not power your gear from someone else's battery box in case they have wired it in a none standard way - like I have.  It should not matter if you are using it just yourself and your own cables that you made for your own box.

Even with a large 110A battery like this, it is remarkable how fast you can run it down.  Camera/focuser/mount/dew heater(s) and a laptop (charged from the mains at the beginning) and it will run it to below 12.2v in an all nighter.  A second night and it will exhaust the battery and it will be down at 10.5V.  Too much of that would wreck a standard lead acid car battery so it is important to use a marine/leisure battery.  I make sure I charge it after every use.

[kirkster501]

I am going to rewire my box according to Alan's method.  I have blown individual fuses several times now.  I think this is because the 12v is making contact before the ground, as explained by Alan.

[symmetal]

7 hours ago, kirkster501 said:

I am going to rewire my box according to Alan's method.  I have blown individual fuses several times now.  I think this is because the 12v is making contact before the ground, as explained by Alan.

If the 12V connects before the ground then it's possible the device will find a temporary ground via a USB cable or maybe other metalwork in contact before it gets its proper XLR ground. While not desireable, as a USB cable or similar route will be higher resistance so leading to a momentary low 12V on the device just connected, I can't see this in itself causing fuses to blow.

What value fuses have you used for the ones blowing, and powering what? Car blade fuses under 20A from the usual sources are almost certainly quick blow types so it may just be the initial power surge on connection eventually blowing them if they're too low. I use a 5A fuse for the mount and 3A fuses for the other items.

Re-wiring the XLRs with conventional pin numbering is a good move though, if you have the inclination to do so. 🙂

Alan