Power tank question

[brrttpaul]

Been reading up and asking questions about a suitable power tank and decided on going down the homemade type route. Ok I have been in a place where they supply batteries and after some advice I can get a box a deep cycle leisure battery and instead of buying fuse boxes, sockets etc I can also get a sine wave invertor? that has two plug sockets and a USB on it so basically everything will be in the box and I dont even have to change the plugs on my leads. Or was a just given the hard sell be interested to hear your thoughts on this, yes I can do it cheaper but me and electric dont mix all I want to do is plug it in and concentrate on the sky

[faulksy]

best to go 12v all the way, using a inverter your using 220v ,also if you go 12v you can run optics heaters

[ronin]

Since just about everything in Astro World runs off 12V DC putting an inverter in seems somewhat pointless and irrelevant.

[Davey-T]

All inverters are not equal and can cause interference, no point making problems, if you stick with 12volt and 12v / 5v USB converters you can't get into much trouble, if you're thinking of carrying it far and want to spend money then Tracer LIPO batteries are worth considering.

Dave

[brrttpaul]

So what exactly do I need?  If I get the deep cycle battery  I ask for a 12v one then?. and after that I would need a fuse box and wires and cigarette/usb sockets, then I would have to connect them all together in some shape or form, plus I would have to change my leads then wouldnt I as they are the standard plug. 

[nigelbeaumont]

If you want to go down the inverter route, then you need to buy a 'pure sine wave' type. More expensive than a basic inverter, but much kinder to sensitive electronics like mount motherboards, cameras etc.

[brrttpaul]

I just want the easiest option lol, pretty sure it said sine wave on the box but cant say it said "pure"  its £100 if thats any help

[Coastliner]

What are you wanting to power off it that needs mains? As has been said before, pretty much everything you need runs off 12v. If you and electricity don't mix I would go for one of the car jumpstarter packs. I got mine from Maplins, it has 2 12v outputs plus usb, led light, etc. you can get one with a mains inverter built in.

[brrttpaul]

just a Heq mount possibly the focuser and maybe a laptop though Im hoping the battery of the laptop will be ok for that. I was going to get the Skywatcher power tank which to me seems the easiest option but I keep getting told its a bad investment that they dont last

[Physopto]

What ever you do be safe.

240 volts outside is not safe.

No matter what any one says you cannot make 240 volts outside safe in a damp environment. When there is dew on equipment you will be touching it.

Why go a route where you convert 12 volts into 240 volts and then back down to 12 volts. You are adding complexity for no reason, other than allowing you to use the original power 240 volt supplies. Each time you change the voltage from one thing to another you loose efficiency and therefore loose power. Far safer and sensible to stay at 12 volts, the battery will last longer.

Use the biggest battery you can manage ( if possible use a 110 ah). If you are using it at home you can use a long lead out to the position you want to observe from or image from. Use the heaviest wire you can to reduce voltage drop (voltage drop due to resistance in wire is reduced the bigger the cross sectional area of the wire). Then use a distribution box. Use in line fuses of the correct rate to each bit of equipment.

Safer for you, safer for the equipment if done correctly.

Just make sure you check the polarity of each wire and plug before you plug it into your equipment, you don't want to blow up any of your gear!

Best of luck

Derek

[brrttpaul]

Think I will just get the Skywatcher power tank save the hassle, What do i do about the plug lead on my mount as thats a 3 pin socket and obviously the power tank has usb and cigarette sockets but no 3 pin, do i just cut the plug off and attach a cigarette type jack or do i need to buy a new lead

[Physopto]

If you are unsure I really suggest you buy the new lead, as you are going to purchase a power tank.

Power tanks are not the best solution if you are using a lot of power. By this I mean mount, camera and dew bands. It depends upon time as well. The biggest battery in the power tank the better.

[rob0971]

There are plenty of DIY threads on here including mine http://stargazerslounge.com/topic/197315-diy-power-pack/

They should give you plenty of ideas & answer some of your questions. If you are unsure about anything ask.

Cheers

Rob

[brrttpaul]

thx for all the replies guys

[Davey-T]

If you get the Skywatcher one when the battery dies you can fit a Tracer one in it instead, that's what I did with my Maplin one.

When you say your mount has a three pin plug do you mean it's got a 240 volt power supply ? if so you need to but a 12 volt power lead for it.

Dave

[jimbo747]

B&m doing a car charger with 12v socket for under £30 which seems decent value. As long as you don't drain it over 50% and keep it charged it should be alright.

[brrttpaul]

thx guys just catching up with this, yes I did mean a normal house plug at the moment, I presume I need to buy a new lead with cigarette plug one end and the fitting that goes into the HEQ5

[michael.h.f.wilkinson]

BTW, some electronics need 6V (SW dual axis drive controller now attached to my mount) or 9V (my old Vixen MT1 controller), so having options beyond the 12V only can be handy. Converting 12V DC into 9 or 6V is easy, of course, but these voltages are supplied standard by the SW power tank.I did have to replace the battery with a 22Ah deep cycle one (drop in replacement) which is a lot cheaper than the (much lighter and more capable) LiFePo drop in replacements I have seen

[Skipper Billy]

@brrttpaul   For the price of a powertank you can buy a 75 - 110 amp hour battery (MUCH more capable) and it will last a lot longer.

If you need a branch making up ie 2,3,4,5 or 6 etc 12v fag lighter sockets onto a common pair of leads to go directly onto the leisure battery terminals just drop me a PM and I will gladly make it up for you - you just pay for the parts and the postage I am not looking to make money out of it  - I can also make you up a lead for your mount with a fag lighter plug on the end.

I would much rather do this than see someone chuck £100 down the toilet for something that wont last long and is inappropriate for the task in hand.

You can buy a leisure battery (NOT a car battery) from any local caravan or boat parts place/chandlery or online but the carriage costs can be high (they are heavy - a 75 amp hour battery weighs about 25kg).

The advice given above is all good - please dont take 12v to 240v then back down to 12v again - its inefficient, can cause issues and can be dangerous. 240v plus water = short imaging session ;-)

I am a boat electrician so I am familiar with 12v ;-) and a bit of damp will not be a problem !!!

[brrttpaul]

I just seen a youtube vid on another post here in regards to making a power tank it seems easy enough if the video is anything to go by, all it needs to do is run a HEQ5 mount and a laptop running cdc

[brrttpaul]

Just noticed your post (must have been typing at the same time) I can get a leisure battery for £55 the place by me makes or supplies them (SURPAC) I think its called, if you can give me a price for everything else I would need that would be great.

Cheers 

Paul

[michael.h.f.wilkinson]

Bigger batteries are indeed much more capable. If you drain 8.5Ah out of a 17Ah, you have gone down to a 50% charge. Even deep cycle batteries have a reduced life span. Using an 85 Ah battery (for example) you are only draining it down to 90% of its charge, ensuring much longer lifespan. The main attraction in the powertank is its compact and lighter build (and the extra outlets for other voltages, which you do not need). Powering multiple cigarette-lighter sockets out of a battery is just a matter of simple wiring, really.

[jimbo84]

I currently run my SLT mount direct from Lucas AGM batteries out of my grannys mobility scooter - I have a 12v car socket wired to the terminals and just use a springy 12v car socket cable to connect to the mount. The battery sits on the tripod tray, so nice short cable to not trip over. It runs for hours, no problems. I just rotate in a charged one next session while the other is topped up.

I expect you will need more capacity to accomodate the laptop, but same principle.

[brrttpaul]

Going to take the plunge and go down the home made route, at the moment I need a 12v battery, 12v blade fuse box, 12v cigarette sockets, 12 v wire, 12 blade fuses and a box to put it all in, for the mount I will need a lead with a cigarette type fitting, think thats about it innit? oh and the terminals to attach the wire to the battery

[Physopto]

I would suggest then that you go for the largest battery you can manage.a while ago some of the members were fitting it all into cool boxes. They are shower proof to rain (if you get the right one). You can get a 20 to 30 amp hour battery into a reasonable sized box.