Power ... out in the field (12v questions)

[autonm]

Ive read a few topics on these forums - however each seems to be specific to a setup. Closest I found was from this post here

I am looking at this battery: Hankook Leisure XV27 90Ah here

To be carried in this Battery Box 0 LED Meter, Breaker, USB Socket, 12v Cigarette Socket (output) here

 

I am powering the following equipment:

Pegasus Power Box 0.1Ah (nothing connected)

2 small dew bands 1.4Ah each (2.8Ah total)

Canon DSLR via a Battery Coupler (0.5 Ah - probably lower)

HEQ5-PRO mount when slewing max (2Ah)

Laptop mains power supply on this is rated INPUT 100v-240v 1.5Ah ... and OUTPUT 19v / 3.42 Ah

NOTES

The Pegasus Power Box - is currently powered from the mains, however I have a 12v DC Cigarette adapter.

 

Questions

How do I power the laptop from the Battery box? do I need a convertor such as this  .... how do I know if I need 300w or 500w?

As the Battery Box only has 1 x 12v output, can I split this - using one of these ... one would have the convertor (above) running out of it - and the other the Pegasus Power Box 12v DC adapter.

 

My future hope is to drop the laptop and replace it with a 'windows on a stick' type of setup. 

... am I missing anything? or is there a UK based Battery Box - with 2 x 12v DC sockets? 

Running I think the 90Ah battery - am I right I could run the above for 10 hours everything being perfect.. but at least for several hours. 

 

 

Thanks

 

Edited August 30, 2021 by autonm

[teoria_del_big_bang]

There are various options, I will have a think and get back to you later today, I am sure many others will also offer advice as there are several threads all about the same difficult issue on SGL from earlier this year.
Steve

[Len1257]

I recently bought one of these for use with a NUC :- https://uk.rs-online.com/web/p/car-chargers/0417916/ 

Tried it out seems to do the job. Invertors not the most efficient way to go. Losses in converting to 230V then more losses in the 230 to 19V. Best to do it in one operation.

I was put off the cheap buck convertors on Amazon by the various negative reliability reviews.

There are umpteen car 12v DC Cigarette adaptors on Amazon and Ebay. Just need a box to mount them on assuming you are OK with how to wire them up. I found the crimps to be not compatible with my crimper tool so ditched them and used my own.....

Your laptop supply will be 19v / 3.42A not Ah. In which case 19 * 3.42 = 65W .

[teoria_del_big_bang]

11 hours ago, autonm said:

Questions

How do I power the laptop from the Battery box? do I need a convertor such as this  .... how do I know if I need 300w or 500w?
Personally I shy away from inverters, they are pretty inefficient boosing 12V up to 240VAC then plugging a power supply in to then convert the 240VAC to 19V DC.
Now I have no experience of THESE but they get some decent reviews on Amazon (for what that is worth) and would seem a better option of I were to go that way.
Also if you do eventually get a NUC, RPi or Windows stick that runs somehow from the 12V supply actually on the mount then you can remote desktop, Teamviewer etc to it from your laptop at a distance and maybe even sit in the car with the laptop and then use the 12V supply in the car with this (just a thought).

As the Battery Box only has 1 x 12v output, can I split this - using one of these ... one would have the convertor (above) running out of it - and the other the Pegasus Power Box 12v DC adapter.
Yes that would work but I would be wary that it may give poor connection as it rocks about with two cables dangling from it.
To be honest in my opinion I hate those cigarette socket type connectors anyway and wonder why the hell so many Astro bits of kit use them, the sockets were never really designed for constant use and make reliable connections, so I try never to use them anyway and replace any with other reliable connectors.
If going the multiple socket route I would prefer one of THESE If you search you can get then with 3 or even 4 sockets.
A better solution is to add your own secondary (or more) connectors to the box is there is room, quite easily using THESE

My future hope is to drop the laptop and replace it with a 'windows on a stick' type of setup. Certainly the way to go for remote imaging.

... am I missing anything? or is there a UK based Battery Box - with 2 x 12v DC sockets?  I don't think so, hence my suggestion of adding your own. If you can solder, or know somebody who can do it for you, I suggest cutting off all your cigarette type connectors and replace with THESE to give much more reliable connections that will not pull out when you catch then with your feet in the dark.

As I said I think powering a laptop in the field is the difficult one, they run at a strange voltage and are power hungry, and to top it all most are pretty poor on battery life after a few months of use.
To be honest I haven't had the need to do so as I run my rig from an RPi that can run through a converter from the 12V, a NUC or similar running direct of 12V is even better option.
Yes I still need my laptop to set everything going but once imaging I can put it to sleep and just wake it up every so often to check how things are going, so battery life is pretty good and can see me through a night.
Also I must add my nights of remote imaging so far are few and far between so although I have prepared for it most sessions have been from my patio running off mains, although I have built a 12V supply and have tested it out a couple of times successfully but most times due to the few clear nights this year have not risked it and run everything of 240V supplies.

One other thought when you change to some sort of small computer at the mount is to ditch the laptop to communicate with the computer and use your phone or a tablet that is less power hungry and will last a night on battery and if not easy to charge from 12v with the right adapter.
All depends on what program you are running on the computer I guess and if you can use an App to talk to it. I tend not to go that direction as my eyes are not great and would struggle to see such small screen.

Steve

 

[autonm]

thanks. Yes - my future plan is to go NUC... and then remote desktop / VNC - from a laptop .. or even ipad - so I can heck every 30 mins or so.

The only issue to overcome in the field with a NUC ... and checking from a laptop - is in the field there is no 'house wifi' for them both to connect to. To overcome this I think I have to buy some £30 router - which creates its own network - that both can connect to. Basically what RPi does.... maybe RPi - could actually do that for me ... thats a future project

 

But at the minute i'm thinking of - leisure battery, the battery box with the 12V output on - then buying an invertor allowing UK plug to be used ... but just add a double socket / extension. That way I can power my Pegagsus box, which handles everything ... and then the 2nd socket is if I did need to top up the laptop battery. Ive been told that for the invertor though I need a 'Pure Sine wave' to give a 'cleaner' flow.

 

Looking at your profile... I'm up in Newcastle - not to far from Skipton area. Hope you do get some clear skies and dark skies round there. I'm about 50 minutes driver from Kielder area - one of the identified dark sites - hence my reasoning for wanting to try and be able to go out in the field ! 

 

 

 

 

[autonm]

7 hours ago, Len1257 said:

I recently bought one of these for use with a NUC :- https://uk.rs-online.com/web/p/car-chargers/0417916/ 

Tried it out seems to do the job. Invertors not the most efficient way to go. Losses in converting to 230V then more losses in the 230 to 19V. Best to do it in one operation.

I was put off the cheap buck convertors on Amazon by the various negative reliability reviews.

There are umpteen car 12v DC Cigarette adaptors on Amazon and Ebay. Just need a box to mount them on assuming you are OK with how to wire them up. I found the crimps to be not compatible with my crimper tool so ditched them and used my own.....

Your laptop supply will be 19v / 3.42A not Ah. In which case 19 * 3.42 = 65W .

Yes - NUC is where I want to go with in the future... maybe sooner than later. Have you tried the NUC out in the field - and if so - how did you create a wifi spot for the NUC and tablet? to connect to - so that you could VNC / Remote Desktop into the NUC and check everything was good?

 

thanks

[teoria_del_big_bang]

You should not need a router in the field but create a hotspot on the NUC (I assume you can do this as I can with the RPi) then connect to that hotspot with the laptop or tablet.

Another solution is to buy a 100M flat Ethernet cable and connect through that. Yes its another cable and WiFi would be better but it is cheap, and I say the flat cable as these tend to be lighter and go through very narrow gaps like a car window that is practically shut and the great advantage is they are very reliable and fast transfer of data to laptop.

Steve

Edited August 31, 2021 by teoria_del_big_bang

[Len1257]

15 hours ago, autonm said:

Yes - NUC is where I want to go with in the future... maybe sooner than later. Have you tried the NUC out in the field - and if so - how did you create a wifi spot for the NUC and tablet? to connect to - so that you could VNC / Remote Desktop into the NUC and check everything was good?

I decided ages back that tripping over cables wasn't going to be something I wanted to repeat so I made up a battery box with a 36Ah LiFePO4 battery and remote into my rig. It's only 10m away from my conservatory and I have a wifi repeater in there so wifi is not a problem for me. I am intending to use the above mentioned adaptor to power the 19V NUC with NINA / PHD2 etc running on that. I use TeamViewer to remote in from my laptop. Just bought a new mount so my rig is in transition at the moment.

[JimothyC]

That adapter looks great, but if you want a slightly cheaper option and don’t mind a bit of wiring, I’m using one of these on my nuc.https://www.amazon.co.uk/dp/B08DNDGZT7/ref=cm_sw_r_cp_api_glt_fabc_ZC01W7VD2498C8R7KM33?_encoding=UTF8&psc=1

although most NUCs should be able to run on 12v. Although they ship with with a 19v PSU if you dig into the specs you should see that they’ll run on 12-19v  https://ark.intel.com/content/www/us/en/ark/products/83254/intel-nuc-kit-nuc5i5ryk.html  If you’re using a lifepo4 battery and a fairly short cable, it should be able to consistently deliver over 12v and you won’t need an adapter at all.   

in the end I went for an adapter as I wanted the option of fairly long cables and the possible voltage drop may have brought things below 12v towards the end of the batteries charge 

 

 

[Len1257]

Unfortunately I  purchased a NUC 10 series. These are exclusively rated for 19V. Didn't realise the issue as I had read in so many places the 'works OK on 12V' bit. Something to be aware of.