How to power scope from my car

[ClaireBradshaw]

Hi all - I want to have the ability to take my car (Vauxhall Zafira 06 if that makes a difference) to a dark site and power my scope and possibly laptop using the boot 12v ? power port. Is this possible? The car has 3 such ports. 

 

The mount is a Skywatcher Eq3 pro and the laptop is an older Sony Vaio Intel i3. 

 

Thanks for any help!

Claire

[cjdawson]

Yes, it's possible to do it.... but I wouldn't recommend it.

 

Consider this scenario......

 take my car (Vauxhall Zafira 06 if that makes a difference) to a dark site and power my scope and possibly laptop using the boot 12v.    It's a wonderful session, you arrive at 5pm, and pack up to leave at 7am having had the best nights observing session ever.   Tired, you pack everything away, climb into the front of the car, and turn the key to start.... the lights dim, the engine clicks once, then everything stops working.     Yep. It's a flat battery.

Car batteries are designed to give a big punch for a short period of time.  Running it to power a scope and laptop isn't a good idea, without the engine running.    And I'm sure you don't want to be sat in fumes all night long.

 

I have a couple of these car chargers....

https://www.coywood.co.uk/car-chargers-1318-c.asp

One for my MacBook Pro, and the other for my HP Pavillion.   They both work well running off 12v and yes I do recommend them both.

 

 

So, if I don't recommend plugging into the car, how do you power them?    Well that's simple, there's a few options.

1. Tracer batteries - https://www.tracerpower.com/tracer-lithium-polymer-battery-packs.html    Not cheap, but will work.

2. Leisure battery - http://www.halfords.com/camping-leisure/caravan-motorhomes/electrical-power/halfords-leisure-battery-70ah, 1/3 of the price, but it's heavy.

3. Jump Starter - http://www.halfords.com/workshop-tools/garage-equipment/battery-chargers-jump-starters/halfords-6-in-1-jump-starter-usb-inverter-air-compressor-led-12v-dc?_br_psugg_q=jump+starter

These work too, they tend to be based on a 17Ah Sealed Lead Acid battery.  Some have inverters built in, which will run your laptop, but they're inefficient when compared to the 12v dedicated supplies.

 

I'm sure they are other options for power as well.   I simply don't recommend using your car as the power source, as you might find you get stuck and ruin what was a wonderful night.

[Cosmic Geoff]

The mount itself should not be a problem, as a small battery will power it for ages. It's when you add laptops, dew heaters etc that you should start to be careful.

[AngryDonkey]

I've had best success with deep cycle leisure batteries. They are heavy and fairly pricey but seem to last a long time and don't mind a deeper discharge. I've used normal car batteries before but noticed a big deterioration if they were depleted too low (which is sometimes hard to judge).

[Davey-T]

The mount won't take much but the laptop could flatten your car battery then you'll be stuck in the field all night.

Dave

[Louis D]

Car batteries have a multitude of thin lead plates to get high instantaneous amperage that can hole through if the battery is thoroughly discharged.  Once any plate holes through, the whole battery is useless.  Get a deep cycle marine battery like those used for trolling motors.  They have rugged, thick lead plates designed to tolerate deep discharge.

[ClaireBradshaw]

Hey okay... so if I got a Leisure Battery, 

1. Any ideas how you power the scope and laptop from it?

2. How do you recharge it? 

I had a recharging pack before but it went flat after awhile. I recently broke up with my partner - I used to reel out an extension lead but now I'm stuck wirhout power. But I'm not going to let a crappy marriage put a stop to my astronomy so I need to get something implimented

 

claire 

[ClaireBradshaw]

Are these any good?

https://www.amazon.co.uk/gp/aw/d/B007Y9HUIA/ref=mp_s_a_1_1?ie=UTF8&qid=1527344348&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=portable+power+skywatcher&dpPl=1&dpID=41H1cq-IETL&ref=plSrch

[Cosmic Geoff]

1 hour ago, ClaireBradshaw said:

Are these any good?

https://www.amazon.co.uk/gp/aw/d/B007Y9HUIA/ref=mp_s_a_1_1?ie=UTF8&qid=1527344348&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=portable+power+skywatcher&dpPl=1&dpID=41H1cq-IETL&ref=plSrch

It looks suitable for powering your mount. Note that it is only 7AH.  The reviews say that a charger and telescope lead come with it.

[Cornelius Varley]

3 hours ago, ClaireBradshaw said:

Are these any good?

https://www.amazon.co.uk/gp/aw/d/B007Y9HUIA/ref=mp_s_a_1_1?ie=UTF8&qid=1527344348&sr=8-1&pi=AC_SX236_SY340_QL65&keywords=portable+power+skywatcher&dpPl=1&dpID=41H1cq-IETL&ref=plSrch

It would power your mount, but adding a laptop would quickly drain it. The best option is a high capacity deep cycle leisure battery.

4 hours ago, ClaireBradshaw said:

Hey okay... so if I got a Leisure Battery, 

1. Any ideas how you power the scope and laptop from it?

2. How do you recharge it? 

1. The mount could be powered directly and the laptop would need a voltage inverter to convert 12v to 240v.

2. A charger suitable for deep cycle leisure batteries.

[Davey-T]

Something like an 80Ah leisure battery will power everything all night, anything more Ah will get a bit heavy, get a smart charger for it and leave it plugged in when not in use.

Look on EBay for Lavolta 12volt laptop chargers to suit your laptop.

You can get a mount power cable from FLO.

Then a multi cigarette socket adapter with a couple of crocodile clips to connect to the battery, just be careful to get the polarity right.

A better solution is a homemade power supply with the battery in a tool box with wheels and sockets built in, lots of examples in the DIY section.

Dave

 

[cjdawson]

Here's how I solved the issue....

1. battery

http://www.halfords.com/camping-leisure/caravan-motorhomes/electrical-power/halfords-leisure-battery-70ah

Something like this will get you going.

 

2. Charging it.

http://www.halfords.com/workshop-tools/garage-equipment/battery-chargers-jump-starters/halfords-smart-battery-charger-vehicles-up-to-2-0l

 

How do you connect it to the scope?

Something like this will get you going.

https://www.ebay.co.uk/itm/Car-Battery-Terminal-Clip-on-Cigarette-Cigar-Lighter-Power-Socket-Adapter-12Volt/142465755088?epid=2231703568&hash=item212b9ee7d0:g:F5YAAOSw8FtZhDV9

 

But I need more than one socket. This will get you 4 sockets and 2 usb sockets too, so you can charge your phone, or tablet too.

https://www.ebay.co.uk/itm/4-Way-in1-Car-Cigarette-Lighter-Socket-Splitter-12V-24V-With-USB-Plug-Adapter/263384126772?epid=5018636929&hash=item3d52ead534:g:hUoAAOSwq4VaL7G6

 

How do you power the scope?   Here's an off the shelf answer.

https://www.firstlightoptics.com/astronomy-cables-leads-accessories/lynx-astro-mount-power-cable-for-sky-watcher-mounts.html

However as £23, that's a lot of cash for a cable.   I've personally only ever build me power cables.

 

And powering that laptop?

I do recommend these chargers.  https://www.coywood.co.uk/car-chargers-1318-c.asp    I've got 2, one for an 85W MacBook pro. The other for my HP Pavillion, if you can use one of these, great.   It's a really nice option.

Next best would be something like this....

https://www.ebay.co.uk/itm/UNIVERSAL-DC-DC-CONVERTER-for-Laptop-12V-3300mA-Car-Truck-Van-Output-15V-24V/323173301642?epid=1866746182&hash=item4b3ea13d8a:g:k8MAAOSwGfNZzuFa

I've tried something like this before with my Old tempremental Sony Vaio, it worked.  However it did cut out when the battery voltage dropped a little.  The ones from CoyWood are far more tollerant of leisure battery voltages.    Your milage may vary, depending on your laptop.

 

Last resort - an inverter will change 12v to 240v ac so you can power the laptop.

https://www.amazon.co.uk/MASCARELLO®150W-Power-Inverter-Outlets-Adapter/dp/B0714DRPF8/ref=sr_1_2?ie=UTF8&qid=1527436902&sr=8-2&keywords=12v+mains+inverter

Why is this the last resort?  It's inefficient compared to the other options above.  It also means that there's 240v AC outside in the dark, so extra care needs to be taken to keep moister away from this.

[bruno]

I have a 20 000 mah battery that runs my mount quite well, you will find them on ebay mine was about £30.00 but i think they do them with two usb ports now?

[cjdawson]

don't forget that when someone is advertised as 20,000 mah and has usb sockets only, it means 20,000mah at 5v.   To run stuff at 12v you need to convert it.  Where as 70,000mah (70Ah) at 12v is more like 140Ah at 5v.

[ClaireBradshaw]

Thanks for the info CJ and that's a lot of good information and detail - I was looking for a one off cost that wasn't going to cost an arm and a leg (Recently separated and being bled by rent and mortgage). I had a load of Amazon vouchers built up and was hoping for a solution there but was messed around by several sellers from the far east. I also have seen large capacity small car starters at 20,000 mAh but have no idea if they will run the EQ3 for more than 1 second to several hours. There seems to be no middle ground - either all in or get a poor 7ah supply. I'm not complaining I just am perplexed as how I can spend a reasonable amount in my situation. 

The car starters minis (like this https://www.amazon.co.uk/EletecPro-14400mAh-Emergency-External-Flashlight/dp/B07BB7L9W4/ref=sr_1_4?ie=UTF8&qid=1531095572&sr=8-4&keywords=portable+power+car+starter) seem to have a connector for the croc clips that can be replaced by a 12v socket. A leisure battery is the route of choice, but if on a budget looking to upgrade later, would you think this would power the motors? 

 

thanks again for all your help

 

Claire

[Sunshine]

for dew heater and laptop I use a heavy duty deep cycle marine battery, was pricey at $250 CAD dollars but I think it is nuclear because it powers whatever I throw at it without complaining.

[cjdawson]

8 hours ago, ClaireBradshaw said:

Thanks for the info CJ and that's a lot of good information and detail - I was looking for a one off cost that wasn't going to cost an arm and a leg (Recently separated and being bled by rent and mortgage). I had a load of Amazon vouchers built up and was hoping for a solution there but was messed around by several sellers from the far east. I also have seen large capacity small car starters at 20,000 mAh but have no idea if they will run the EQ3 for more than 1 second to several hours. There seems to be no middle ground - either all in or get a poor 7ah supply. I'm not complaining I just am perplexed as how I can spend a reasonable amount in my situation. 

The car starters minis (like this https://www.amazon.co.uk/EletecPro-14400mAh-Emergency-External-Flashlight/dp/B07BB7L9W4/ref=sr_1_4?ie=UTF8&qid=1531095572&sr=8-4&keywords=portable+power+car+starter) seem to have a connector for the croc clips that can be replaced by a 12v socket. A leisure battery is the route of choice, but if on a budget looking to upgrade later, would you think this would power the motors? 

 

thanks again for all your help

 

Claire

The thing that you need to know about those devices is that the 14400mAh is based on 5V being used.  They're a huge compromise, when run at 12v they're more like so you can half that before you even begin.

[Skipper Billy]

I would strongly counsel against powering your rig from your car. My other hobby is flying radio control helicopters and the number of people needing a jump start to get home because they recharged their lipos for the heli from the car battery is very alarming.

As has already wbeen pointed out but worth repeating - car batteries are not designed for long periods of low output they are deisgned for massive blasts of power for verly short periods then immediate recharging.

The best solution for you would be a medium sized leisure battery (75ah) and a transformer like the one linked to above - using an inverter to go to 240v to drop it back down to whatever your laptop needs is grossly innefficient.

I would also suggest using the opportunity to get rid of the fag lighter plugs and sockets they cause all sorts of problems.