roger94 Posted September 29, 2009 Share Posted September 29, 2009 Is it possible to use a car battery instead of an expencive powertank? If yes, how? Link to comment Share on other sites More sharing options...
Vega Posted September 29, 2009 Share Posted September 29, 2009 Yes, I've used one on my EQ6 before by getting crocodile clip > cigarette lighter adaptor from maplins. I also got a 4 point cigarette lighter adaptor to add dew heaters and any other 12v appliances. For the mount I used a cigarette lighter to EQ6 power cable from astronomiser. A word of warning though, car batteries are not deep cycle batteries (they are designed to crank a car from cold rather than prolonged 12v of power). I often found my EQ6 struggling when slewing in both axis after a couple hours use due to the drop in battery juice.Matt Link to comment Share on other sites More sharing options...
red dwalf Posted September 29, 2009 Share Posted September 29, 2009 you would be better off with a leasure battery, i.e. the ones for caravans and alike, you can pick up 40 amp versions for about the £40 mark, 40 amps should give you 20 hours service at 2 amp per hour Link to comment Share on other sites More sharing options...
roger94 Posted September 29, 2009 Author Share Posted September 29, 2009 Thanks for the answers:)What about a jump starter- battery? Link to comment Share on other sites More sharing options...
red dwalf Posted September 29, 2009 Share Posted September 29, 2009 there not bad, i think the batteries on these are in between the two. hold charge better than a car battery but not as good as a leasure battery Link to comment Share on other sites More sharing options...
Merlin66 Posted September 29, 2009 Share Posted September 29, 2009 I've been using 20Ah gell cell batteries for the last few years. With a good electronic charger they seem to last forever. One for the scope and one for the "extras"Pays for itself very quickly. Link to comment Share on other sites More sharing options...
ncjunk Posted September 29, 2009 Share Posted September 29, 2009 Gotta say any deep cycle battery (marine battery for instance) would be the best choice. A lot of those power tanks are only 17Ah which won´t last too long if you have a lot of things connected.Also I understand that some Batteries tend to last longer if you don´t fully discharge them, therefore if you take them to 50% of charge and then recharge it will last longer than if you are taking it to 15% of charge and recharging.Having said all of that I am using a cheap jump starter battery (with the leads and the lights) and it looks like the power tanks you can buy in other places. It is 17Ah and I am using it to power the cameras and the filter wheel. I will get a deep cycle one when I have the money....and a solar charger...Neil Cp.s. and in answer to the inital question a car battery is usable but will last less time :-A car's battery is designed to provide a very large amount of current for a short period of time. This surge of current is needed to turn the engine over during starting. Once the engine starts, the alternator provides all the power that the car needs, so a car battery may go through its entire life without ever being drained more than 20 percent of its total capacity. Used in this way, a car battery can last a number of years. To achieve a large amount of current, a car battery uses thin plates in order to increase its surface area.A deep cycle battery is designed to provide a steady amount of current over a long period of time. A deep cycle battery can provide a surge when needed, but nothing like the surge a car battery can. A deep cycle battery is also designed to be deeply discharged over and over again (something that would ruin a car battery very quickly). To accomplish this, a deep cycle battery uses thicker plates. Link to comment Share on other sites More sharing options...
roger94 Posted September 29, 2009 Author Share Posted September 29, 2009 Thank you guys!I don't quiet see how to hook up a telescope to a + and a - pole:oDo you need som sort of adapter?And how can I charge it?Sorry for beeing such a noob at this :/ Link to comment Share on other sites More sharing options...
Vega Posted September 29, 2009 Share Posted September 29, 2009 One of these crocodile clip cables will sort the battery end (cheaper from here or ebay though)then get one of these for the telescope mount.I also got one of these so I can run dew controllers, camera etc off the battery tooI use a 4.8watt solar panel, 12v regulator and marine leisure battery. Works a treat Matt Link to comment Share on other sites More sharing options...
Milamber Posted September 30, 2009 Share Posted September 30, 2009 Any reason why a charger cannot be permanently connected to the battery in use? One would then be using the battery as a giant smoothing capacitor and also it would be on charge all the time - rather like a car battery?Arthur Link to comment Share on other sites More sharing options...
Merlin66 Posted September 30, 2009 Share Posted September 30, 2009 If you have the correct type of charger this can ( and is) done.It really needs to be an electronic three stage charger which modulates the charging current and trickle charges without cooking the battery.We use them all the time on our battery operated semi-mobile equipment.Guys,just remember those marine batteries etc are pretty heavy to lug around... you'll soon get fed up with the weight. A couple of gel cell can do the same job, better. Link to comment Share on other sites More sharing options...
brianb Posted September 30, 2009 Share Posted September 30, 2009 Any reason why a charger cannot be permanently connected to the battery in use? One would then be using the battery as a giant smoothing capacitorTrue, but(1) your equipment is liable to be wrecked my massive surges which have been known to come down the mains lines(2) not having a direct connection to lethal voltage AC is IMHO a Good Idea when working outside in the dark dampness.When you're making up a wiring harness for your battery, try to make the polarity idiotproof - most scopes have no protection against reverse polarity connection, their electronics will be instantly destroyed if you get it wrong. Colour coded croc clips are NOT enough as you will not be able to see the colours when working in the dark by the light of a red torch. Also be very careful to make it as difficult as possible to short the terminals accidentally, a 12V high current car battery is quite capable of melting a tungsen steel screwdriver blade. Link to comment Share on other sites More sharing options...
Psychobilly Posted September 30, 2009 Share Posted September 30, 2009 In the OBS I use a 13.8V 20A DC supply which connects to a 110AH Lesiure battery and then run everything of the battery ... Saved me a few times last winter when there were Short power cuts and brown outs.. Every few weeks I partially discharge the battery by runnnig the gear for an hour or so without the DC supply switched on ...Peter... Link to comment Share on other sites More sharing options...
Milamber Posted September 30, 2009 Share Posted September 30, 2009 True, but(1) your equipment is liable to be wrecked my massive surges which have been known to come down the mains lines(2) not having a direct connection to lethal voltage AC is IMHO a Good Idea when working outside in the dark dampness.Hmm.1) Hence the "giant smoothing capacitor" that the battery will become, and that also assuming the mains can get to it - see next2) How will there be a "direct connection" to the mains when the battery charger is supplying 13.8v DC through a transformer?Arthur Link to comment Share on other sites More sharing options...
brianb Posted September 30, 2009 Share Posted September 30, 2009 How will there be a "direct connection" to the mains when the battery charger is supplying 13.8v DC through a transformer?This depends entirely on how the transformer is wired, how the earth is arranged etc. Lots of cheap equipment most certainly does have a direct connection on at least one of the terminals. Spikes can and do get through. Link to comment Share on other sites More sharing options...
Highflight Posted September 30, 2009 Share Posted September 30, 2009 Wickes – Tools, Ladders & Storage – Motoring – Motor Accessories – 12V Power Pack and Compressor Hope this helps.Chris. Link to comment Share on other sites More sharing options...
Highflight Posted October 1, 2009 Share Posted October 1, 2009 Wickes *–*Tools, Ladders & Storage*–*Motoring*–*Motor Accessories*–*12V Power Pack and Compressor Hope this helps.Chris. Oops! Don't bother. Checked this morning and they have sold out. Sorry. Link to comment Share on other sites More sharing options...
roger94 Posted October 3, 2009 Author Share Posted October 3, 2009 Thank you for all the replies. I bought a Celestron C8 NGT yesterday and I got a really good price at the 17ah powertank so I bought it:p I'm very pleased with my new scope and the powertank never seems to go empty! Link to comment Share on other sites More sharing options...
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