Just wondering the best way to run multiple 12v devices from one battery. What is the best way to set it up in terms of specific joiners/adaptors to minimise the number of connections and likelihood of problems?
Is it okay to run multiple things off the one battery or am I going to experience issues.
At this stage I would be running a mount and a dew heater with multiple strips but no doubt other things will follow down the line.
Just wondering the best way to run multiple 12v devices from one battery. What is the best way to set it up in terms of specific joiners/adaptors to minimise the number of connections and likelihood of problems?
Is it okay to run multiple things off the one battery or am I going to experience issues.
At this stage I would be running a mount and a dew heater with multiple strips but no doubt other things will follow down the line.
Here's a photo of one guy's solution. The top of the box is hinged and the supply cable goes inside. He used marine grade lighter sockets. You could do something similar with Anderson Power Poles.
I've got something simpler with a 20A circuit breaker and red flashing LED across the input to warn if I accidentally reverse the jumper leads that supply it from a battery or lab power supply. No blink == power reversed.
No problems so far with a Gemini, Mount Hub Pro, two cameras and dew heaters.
You might look at boating and caravan parts suppliers. They have a range of multiple socket parts that you could building something like the previous post. An amp meter is a good idea so you can see how much you are drawing off, that way you can calculate how long the battery should last.
Is it okay to run multiple things off the one battery or am I going to experience issues.
How big is the battery ?
If it's a small 7Ah one then probably not ...... if it's a nice big 100Ah deep cycle battery, then go your hardest. You just need to work out your average load - I am pretty sure dew heaters and straps will some approximate specs on them to help you here. The mount is the harder one as it depends on whether or not it is goto or just tracking.
Simply running multiple items of the one source is fine but you are right in your question setting it up is important.
1 - What items are you running and how many amp do you need to run them.
2 - what is the size of the battery and the output ratings.
3 - how long do you intend to run the items for.
As far a connecter go and how to hook everything up you need to be careful here.
DO NOT just use alligator clips on every thing and connect one to the other - especially if using car batteries etc, they will cause you heap of issues. Some people will disagree but clamping one clamp to another will cause breakdown in voltage (current) and sparking. If the items being connected to each other are electronic, computers mount etc, there is nothing worst than having it all going and bumping the claps for it to spark. This can cause pulses into circuitry and destroy items.
What I have down in the past for astronomy, mechanical, camper trailers etc is build a distribution box. Quite easy and depending on the type of current draw, quite easy to make.
I will try and explain a simple system and others may like it as well.
Part list
Jiffi Box
2 x anderson plug
4 port RCA panel (female connectors)
4 RCA male plugs
Small fuse box for blade fuses
some 15 amp wire twin core (around 4mm)
Some thinner wire if not needing higher amps.
2 battery terminal (car bat) or bolts for other batteries
Solder, connectors and some bit and piece.
Jaycar electronics for most parts, start with a jiffi box which is a blank box for mounting switches etc to which is sealed and can be purchased in different sizes.
*Drill holes to mount the RCA Wall plate or panel.
*Attach Anderson plug to jiffi box for power in (from Battery)
*Cut 15 amp twin core cable to length required and attach (both end) Anderson plugs
*attach battery clamps to battery. Use twin core wire, one end to another Anderson plug and the other end connect to battery terminals.
*ON the positive side of Battery attach a max size fuse inline. I would suggest 20 to 50 amp.
Know you have a power source from the battery to jiffi box that is protected.
Ok ( hope) you are still following, not real good explaining in words all of this, time to connect the output power.
working at the jiffi box
*ONE black and ONE red ( + and - ) out of the Anderson plug
*Positive to the fuse box
*Negative to a bus bar.
*All the outer RCA plugs can be linked together (negative post) and it can connect to the negative post.
*On the center pin (positive) each individual connect goes back to a separate fuse.
Know for any items that need power, you simple make a cable with RCA male plug to the item and plug it in.
RCA plugs will hold a small current and I have used them to 10amp in a non continuous running environment. I use them for 6amp constant.
The use of MONO headphone jacks is another way of doing it. You can build a battery box and do away with the cable in the middle, I just do that so I don't have batteries at my feet and I can mount the distro panel somewhere and leave. There are plenty of ways to do it, I am sure some more will be listed.
The main this are,
what are you running, how long for and what current required. What size batt do you have. If you are running a 4amp hour battery and your items use 2 amp hour you are only going to get 2 hour out of it?
I will post some images of the latest distro panel I have just mad for a camping trailer, it will give you some ideas.
Some good advice here. Just a few tips from myself:
* Red/black colours are *really* difficult to distinguish with dim red light. The alligator clips I have are very misleading, as under red light the black terminal looks red and vice versa. I've blown a fuse once that way (but luckily no other damage).
* Be careful of voltage drops over to medium-to-long distances.
* Large current draws will reduce the capacity of the battery (a relatively minor amount) but more importantly, it will also drop the voltage very quickly. My EQ6 mount starts acting a little weird intermittently when the voltage is around the 11.7 - 12.0 V mark.
Thanks for the tips guys. Currently I have the mount to run (draws .3 to .5amp tracking more when slewing) and up to 3 dew heater strips. I have 2 x 24Ah batteries. At this point I will run one device off each battery but as I add more stuff in the future I will have to reassess options with more battery capacity and some sort of hub to plug everything in safely and efficiently.
I am not very capable with DIY electrical so will have to find someone who could knock up something for me along the lines of what has been suggested above.
You think there would be some commercial units available that offer multiple 12v outputs and input from a battery you could just buy off the shelf.
Just a note on the jumper packs, A lot of them run 2X 7AH batteries in them which means you will only have 14ah in total. Should be enough for most night but adding everything might start to push the limits for a full night of viewing.
Also note that the batteries they use shouldn't be discharge less then 80 per cent of there total value. This means a 14amp hour battery would only give you 11.2 amp hours. They are also good for around 2000 cycles.
Just as a guide to the jumper pack batteries, I was playing around with the QHY8 I just picked up on the EQ6 mount. After about two hours I wondered why I was suddenly getting star trails, only to find that the mounts wasn't working, the camera didn't mind 11.8volts but the mount didn't. Not sure if it was fully charged before starting (it had been a month ago) but that's what happens when you connect a camera that draws over three amps
The pack has a "battery condition" meter but remember it has to be used under load not without things attached.
