Power for synscan goto

[lexyastroman]

Hi all in the next month i will be getting my first goto telescope First Light Optics - Skywatcher Skyhawk 1145P SynScan AZ GOTO I'm just wondering what could power the scope and a laptop for about anything upto 4-8 hours a night away from the mains? The goto mount states it's 1amp and my laptop is 3.9amps i have found this 3in1 Portable Jumpstarter : InCar Battery Chargers and Compressors : Maplin and it's considerbly cheaper than celestron or skywatcher's 17ah powertanks. Would 17ah be enough for a night's observing? Also one final note would this USB to RS232 - USB Converter Cable: Amazon.co.uk: Computers & Accessories be compatible to connect my laptop to the mount? Any help would be greatly appreciated as i would like to get the accessories sorted before the new scope arrives.

Thanks Lex

[Schorhr]

I don't have experience with this, but as you seldomly get the whole specified capacity out of the batteries, I'dd get a bigger pack... as even with a optimistic guess, 3 hours is not too much.... If both devices run under 12v -> 17Ah : (3.9+1 amp) = 3.4... in theory

But especially out in the cold even lead batteries are affected, and for 6-8 hours I would go with a bigger pack.

Also, if you have the laptop attached with an empty battery, you might want to take it out (as then you would run the laptop AND charge it).

USB/Port adapters: You have to make sure the RS232 is fully compatible (not just a "dumb" cable, if the control does only support rs23s nativly, and that the protocol is fully standard comform, I once had one that would not work with all devices)

[BertUK]

the 17ah power tank will sufficiently run the mount for at least 6 hours as its only 12v but you might have trouble running the laptop aswell as on my experience my laptop requires 19v output from the mains charger,as for connecting the laptop to the mount all you need is a serial to usb cable and the serial end will plug into the supplied serial to rj11 cable that comes with the goto. what i found with the laptop is i bought a power inverter from jtf for about £30 and this converts 12v to 240 from a vehicle cigarette lighter and outputs up to 1kw....this was sufficient to charge my laptop battery when im out in the field,once fully charged on low power settings i got 2-3 hours use before having to recharge from the inverter again.

[Matt2011]

Has anyone has any problems with there Skywatcher 7AH Power Tank, My one has been charging for days and its showing the RED light charging but when I switch to turn the power tank on the GREEN light comes on and says Ready to Use but usually if that is the case wouldn't the FULLY CHARGED light come on but i am not sure if this has been charged or not.

[Chris M48]

I think 17 ah is minimum. Those SLA's don't like to be run right down. I have a similar Synscan setup to you and I use an Ultramax 18Ah (£20 approx) thru a regulated adapter (15,16,18,19,20,22,24 DC 3.5A)Ebay unbranded. If I use my laptops preferred 20v 3.5A setting I start blowing fuses but I find it keeps its charge quite happily at the lowest setting 15v provided I boot up the laptop before plugging in the power and have laptop 100% charged to start with. Although, I have successfully used a splitter to feed power from the SLA to the mount I usually use 10 x AA rechargeables to avoid cables. I also have the Ultramax smart charger (£25 approx) which takes about 6-8 hrs for full recharge (usually overnight). 4 hr sessions no problem 8hrs I dunno! Anyway best of luck and have fun.lol.