Please recomend a good Stand Alone / remote power supply

Louwai (Bryan) · #1 18-11-2007, 07:57 AM

Hi all,
I'm wanting to get myself a power supply for observing where there is no power available.
Can anyone recomend a good setup. I'd like something that would last at least 3 nights before a re-charge was needed.

Items to be powered are
- C8 on a Go-To CG-5 mount (possibly a CGE soon)
- Kendrick heater ctrler + 5 heater straps
- Feathertouch Motor focuser
- Lappy

Knowing me I'll probably add other power sucking bits, so I'd like to get something that will well & truely cover what I need now with power to spare for future additions.

I have been looking at deep cycle batteries, but just not sure about what is best.
Any advice would be appreciated.

Bryan

astromark · #2 18-11-2007, 08:08 AM

Its a pity that us astronomers can not use the suns energy, Its always there and is free... But unfortunately you need for it to be dark. That is a problem.

No, Deep cycle batteries will not do what you expect. Short term, they are fine. You mention three nights before charge and motor drive, keeping your scope moisture free and running a lap top...No.

You are going to run a gen., Its your safe option, and are not so costly.

Lee · #3 18-11-2007, 10:03 AM

It would depend on the size and number of your deep cycle batteries..... I would have thought that a couple of large deep cycle batteries (like 70Ah or so) might get you through - avoiding inverters where possible would help save juice...
A generator might be an easier option....

rogerg (Roger) · #4 18-11-2007, 10:57 AM

I'd guess a 40 - 60 Ah SLA battery together with a solar cell for recharging during the day, or a 70 Ah SLA battery on it's own. I'd expect you to empty about half a 40 Ah SLA in a night with all that running.

asterisk (Geoff) · #5 18-11-2007, 05:29 PM

Hello Bryan

My setup is almost the same as yours. I use 2 x 30amp deep cycle batteries connected to 4 cig lighter sockets (2 banks of 2, switched and fused separately).

The 60amps gives me about 10-12 hours observing time, running all that you mention.

If you wish to get more than this time without recharging, then bigger batteries are required (or 3 nights of 3 to 4 hours each night).
If you want to know more about these batteries then look at

http://www.yhipower.com.au/2007/main...formation.html

Good luck

xelasnave · #6 18-11-2007, 06:15 PM

I have lived this way for 12 years and have just set up my shed...
Get a good battery..as many amp hours as possible, get a $150 two stoke genny from Bunnings and a 8 amp charger (more if possible charger) and a Dick Smith or similar cheap inverter ($50 to $70)... a panel would be nice but you can add it later...mine has panels as well.
But the genny is cheap runing is cheap and you will have all the power you will ever need for cameras, computers mount, hair dryer or heated dew tube, peltier device...wahtever but it is cheap and will always do everything you probably could do in the city... and at home you can use the set up when the power goes off on that rare occassion to have lights and tv... so you are justified spending the money.
Good luck
alex

xelasnave · #7 18-11-2007, 06:19 PM

The idea is to charge it and use the battery by the way ..you have an alarm in the inverter that tells you to turn on the genny if you run low...but a little tester should have you charging before then... dont drain your batteries is the golden rule..how much will depend on the battery but a rule of thumb dont drain past 25% of capacity...that right 200 amp in effect gives you 50 amp hours.
alex

Louwai (Bryan) · #8 18-11-2007, 07:22 PM

Thanks gents. Appreciate your input.

I've been looking at 150ah & 200ah batteries. Rightly or wrongly thinking 'the bigger the number, the better'.
The generator option sounds good, but seeing my wife is an environmentalist, I suspect the solar panels will be a more "acceptable" purchase.

So to that end, can anyone advise what is needed as a solar setup to charge & possibly a reputable place to get the stuff around Melbourne.

I suspect the generator will creep into the shopping trolley also. (just for emergencies)

xelasnave · #9 18-11-2007, 07:35 PM

Happy to hear you will shell the cash for a panel... dont get one from a marine shop or Dich Smith.. Check you may get a cash back on panels someone mentioned thins but I have not looked into it...
You just hook the panel up to the battery..they have built in diodes these days I believe so powere does not leak back..once you had to fit them..some say you will need a regulator but you could drop this as they are really to prevent overcharging.
Rainbow Power Company aty Nibin has good gear and a chat on the phone would help you find a good store nearby but I know they export around the Pacific... but they have serviced the alternate power folk up here for 20 years and are good at this..
alex

asterisk (Geoff) · #10 18-11-2007, 08:37 PM

Bryan

I run solar at my caravan - no 240v available. I got all my stuff, and sound advice on requirements and installation from Windpower Australia:

http://windpower.com.au/

They have good prices (no shop rent) and' last I was there, deliver Australia wide.

Cheers

acropolite (Phil) · #11 18-11-2007, 09:31 PM

Going Solar in Melbourne (Not far from the Victoria market) are an established solar dealer. They have been in the industry for decades and have a wide range of equipment. Expect to pay a little under $10 per peak watt. To determine the charging current from a typical panel divide the wattage by 18 (peak power is delivered around that voltage) so you can expect around 4.5 amps in full sun at noon from an 80 watt panel. On a typical summers day if you get sunshine all day in Victoria you could expect to get around 35 amp hours in to a battery from an 80 Watt panel.

Louwai (Bryan) · #12 19-11-2007, 12:49 PM

Quote:

Originally Posted by acropolite

On a typical summers day if you get sunshine all day in Victoria .

So I need 3 panels then, to make up for the 30% / day of sunshine received in Vic.

Appreciate the advice. Thanks.

erick (Eric) · #13 19-11-2007, 12:59 PM

Set up the panel back in Brisbane, with long leads!

h0ughy (David) · #14 19-11-2007, 01:12 PM

I HAVE 2 15 WATT SOLAR PANELS AND 2 110AH DEEP CYCLE BATTERIES AND 3 PORTABLE JUMPSTART BATTERIES - that just sees me through SPSP

rogerg (Roger) · #15 19-11-2007, 02:50 PM

Wow, I'm amazed how much power you guy's go through! Do you use your batteries down to their "empty" voltage or just half way??

.. since having an amp meter on my setup I've been able to much more accurately track my usage and realised just how little power is being used much of the time.

I guess if you have 2 scopes 3 camera's 2 laptops external hd's, unbalanced mount, etc.... you're going to chew lots, but gez, how do you find the time to setup and dismantle all that power hungry equipment?!

h0ughy (David) · #16 19-11-2007, 03:18 PM

Quote:

Originally Posted by rogerg

Wow, I'm amazed how much power you guy's go through! Do you use your batteries down to their "empty" voltage or just half way??

.. since having an amp meter on my setup I've been able to much more accurately track my usage and realised just how little power is being used much of the time.

I guess if you have 2 scopes 3 camera's 2 laptops external hd's, unbalanced mount, etc.... you're going to chew lots, but gez, how do you find the time to setup and dismantle all that power hungry equipment?!

you just do it, this is packing up from SPSPthis year

(Al meehan pictured) and no I do not have a friendly carbon footprint

Glenhuon (Bill) · #17 19-11-2007, 11:00 PM

I've just scored 2 x 33 AH batteries from my ladies wheel chair (No, she not stranded, new ones arrived on Friday

) and theres a 3w panel in the shed. Should be enough to keep my drives, DSI and laptop going for a night or two.
I did consider going down the generator path, but since we are both environmentally concerned, went for the solar charger.
Not sure that its a good idea to hook the panel directly to the batteries Alex even if it does have a built in diode the input voltage can still exceed 20v on a bright day, not good for the battery. Better with some sort of regulator.

acropolite (Phil) · #18 20-11-2007, 08:24 AM

Quote:

Not sure that its a good idea to hook the panel directly to the batteries Alex even if it does have a built in diode the input voltage can still exceed 20v on a bright day, not good for the battery

Not possible, especially with a 3 Watt panel which will deliver at best 150 milliamps. The batteries will hold the voltage down to a sane level. Even an 80 watt panel pushing 4 amps won't raise voltage levels much over 15 Volts when connected to a decent size battery.

BTW your 3 Watt panel will put back in around 1.3 amp hours per day (sun all day), not really worth the effort of connecting.

KG8 · #19 20-11-2007, 07:17 PM

solar is a good option and I would recommend a single 80 Watt sharp panel at around $800. My panel gives 4.5 amps in full sun and you can start using it at 5am and run it all day if you want. I recommend sharp, which are probably the most expensive, but they are made in Japan and have a 25 year guarantee. Thats 25 years in the sun and rain. I expect mine to last forever unless I drop it!

[1ponders] (Paul) · #20 20-11-2007, 11:36 PM

Quote:

you just do it, this is packing up from SPSPthis year (Al meehan pictured) and no I do not have a friendly carbon footprint

Where's the Duckadang one