I'm after a portable hairdyer and something to run it off, to combat dew on the secondary mirror and eyepieces fogging up.
I've seen a hairdryer that has a car cigarette lighter attachment, but obviously this will be nowhere near the car. Is there an adapter to a 12v battery or something?
And as for batteries, what do I need to get to run this? I don't really need it to run anything else except maybe my Sky Commander.. I already have a small 12v battery (thanks to Westsky), will this work? What cables do I need from the battery to the hairdyer?
Mike you can just go to dick Smith or any electrical supplier....get a cigarette lighter attachment which has 2 open wire's positive/negative.....connect it away you go....
I bought my 12 volt hair dryer from a camping shop in brisbane...they are $22.....
Not anywhere near as good as the 240 volt version.....but it does the job...if you had the power of 240 volt running on 12 volt...I estimate it would last about 30 seconds on that battery pack....
The 12 volt still gets hot straight away but just not to the extreme heat and fan power like her big brother....anyway you shouldn't need a lot of heat to prevent or get rid of the dew.....
Mike if your going to buy another battery Pack,go to Super Cheap Auto's and don't buy anything less than 24 amp per hour ! even the 17amp ain't enough , trust me on this .
Good move Mike ...
This is a good setup, I use it all the time.
If you can get a sealed lead acid battery or even better a Lead acid Gel Cell.
the gel cell eliminates the risk of acid spillage
Takes about a minute of drying for a 8" SCT corrector lens for EG.
PS: enjoying some time in Brisbane at the moment & Looking forward to catching up with some of the Brisbane Iceinspacer's.
Im after a 12v hairdryer also with the colder months comming but i have never seen one for sale. (Not that I have looked before either).
Mike you describe your battery as an A200. That doesnt tell us the capacity of the battery. Something that generates a lot of heat will take a huge amount of power. You need to know the wattage of the hairdryer.
Lets assume the hairdryer uses 100 watts. A 12v 20 amp hour battery can theoretically supply 240 watt hours(12x20) total, or run that dryer for 240/50 = 2.4 hours. It wont be that good as amp/hour ratings are given for a 20 hour discharge.
I have a small 2 amp/hr battery only for running my dsc and that wouldnt get the hair dryer warm before flattening the battery.
Maybe a worthwhile project is a box with a lid for holding eyepieces, with a small fan and heat source to keep the eyepieces toasty on those cold winter nights
Hi guys, See below for your hair dryer and any related dew problems.
Mike, the bigger the better, when it comes to battery capacity. If you can get a 45 ah or 55 ah battery then all the better. If your battery has spade terminals, simply replace the cig. lighter plug. http://www.iceinspace.com.au/forum/s...0&pagenumber=2 For those interested have a look at my heated eyepiece box.
The heater wire is 'electric blanket heater' out of an old blanket. The box is about 15" x 12" x 3" & the heater wire is 300mm long & is glued to the E/Pc tray. It is just warm, but being inside the box, works like a charm. L.
In relation to your comments about power packs, Louie, I found that when I checked my two new 17ah SuperCheap Auto packs the day after the April Starparty the batteries were only half empty. Pretty weird given that the battery powering the Orion dewzapper had an empty reading at the end of the night. I wonder if maybe the meter is just unreliable, and they are didn't drain nearly as much as it seemed.
What did your battery read the next day before you recharged it?
Mike , when you buy the 12v plug the center pin is used for the positive wire, the + on the battery.the 12v I sent you will run the hairdryer ok, but when you use anything that heats, the battery will drain quicker, give the 12v that you have a try and then decide if you need another.
Thanks Rodstar. Can't quite fit the 32mm S/P or UWA 14mm in tho.
Mike, If you already have a battery, just peak charge it the nite before use. Another idea I posted, was to buy a DUAL BATTERY ISOLATOR. These, at present, are only avail. in kit form, from Jaycar > part# ka-1782. Priced @ $49.95. A similar unit is prob. avail. at 4wd centres, but may cost a small fortune. These are mounted in the engine bay/car, & both batterys are connected. As you drive to your dark site, the battery is auto. charged.(sorry about the pun)! It may require slight modification to suit the Gel-Cell,(being an "SLA" battery with diff. characteristics), but there are ways.
How deep are your pockets??? L.
Check with your local Auto-electrician.
ps. And you all thought Astronomy was a cheap hobby!
Rod I think that ,after a battery has been sitting for a while ,it will pick up a charge again " but It will only do this a curtain amount of time before the battery won't hold a charge again. I believe that the 17amp/h battery can't cope with the orion dewzappers power usage.
The best battery's are the deep cycle marine .
Rodstar, without actually monitoring the current going out of the battery it's nearly impossible to tell the state of charge. Factors that effect the reading are temperature, SG of electrolyte and the open circuit terminal voltage. A rough and ready rule is that a 12V lead acid battery with a voltage reading of 12 Volts has 50% charge. When a battery is discharged the lead inside the battery is converted to lead suplhate (and reconverted back to lead during chargeing) and if left discharged for any appreciable time (as little as a couple of weeks) the lead suplhate hardens and the battery won't take a charge. Deep cycle batteries have materials added to the lead to make them more tolerant of deep discharge. Gel or SLA batteries aren't really all that suitable for deep discharge. The best way to prolong battery life is to recharge as soon as possible after discharge and try to keep the discharge as shallow as possible.
Last edited by acropolite; 14-04-2005 at 07:00 PM.
Louie the easiest way to keep a battery charged is one of those $35.00 solar chargers that supa cheap sell, leave it connected at all times and the battery will stay in great shape for years, we use these at our dark sky site and some of these battery's are 5 yrs old.
I use a 17a/hr to run my dew zappers and I get two nights out of them running the dew zappers at 3v. when the dew is heavy I have to up the voltage to 6v and then I only get one night.
Sorry forgot to mention that with the solar charger it helps if you run a 12v regulater inline with the charger, this stops the battery from overcharging, cost about $15.00 from Dick Smith.
Thanks Phil for that info. Sounds like I should always recharge as soon as I get home / the next morning. Will do that hereon to get the longest life possible out of my batteries.
Hi Rod , you are better off keeping the battery on a constant charge, by allowing them to discharge when not being used , the battery life is shortened.
I install fire alarms for a living, these are huge units the type used in highrise apartments and office buildings,
The backup power is 12v gellcell batteries, these are on a constant charge via 240v mains chargers, they last on average 5yrs before they require replacement, A lot of Emergency and exit lights use 6v batteries also on constant charge,these are good for at least 5yr sometimes 10yrs depending on the brand.
The only problem with gellcell type batteries is they do not like being charged constantly with a auto car charger ( they tend to get too hot and split open) hench the reason I suggested using solar chargers.
hope this helps
