Powering the QHY8L CCD with a leisure battery?

[PARTY MARTY]

I currently use my QHY8L on a Skywatcher 17 AH power pack, unfornately due to the 4 to 5 amp power useage from the QHY8L the power pack does not last long I'll be lucky if I get 3 and bit of hours from it!

So I've looked into a 26 AH 12v deep cycle leisure battery which I connect alligator clips with cables which are connected with one cigarette lighter plug which will then allow me to connect the 12v power supply to the QHY8L CCD!

Now I know that the power pack is regulated, I'm not sure if this is safe for the QHY8L to connected to a leisure battery, as anyone done this with method their QHY8L before??

Please help, I don't want buy anything which might damage the QHY8L, until if this could be done??? I was going to use a 12v to 230v power invertor which then supplies the QHY8L power cable, but cos I live in Germany, running a car's engine for long periods is illegal in Germany, So the leisure battery solution is my only method of power?? The QHY8L is thirsty beast requires some power to run it??

Can anyone help?

[PARTY MARTY]

Oh well it seem's that no one can't help me on this one? Thanks for help anyway!

[kirkster501]

You plan on using alligator clips every time? As an ex sparky, I council against that idea. Sooner or later, one night in a hurry or for whatever reason, you are going to connect them the wrong way round; It is a 100% certainty. You are better with a hard wired connection onto the battery in some way like the power pack does.

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[Zakalwe]

You plan on using alligator clips every time? As an ex sparky, I council against that idea. Sooner or later, one night in a hurry or for whatever reason, you are going to connect them the wrong way round; It is a 100% certainty. You are better with a hard wired connection onto the battery in some way like the power pack does.

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+1 million

Crocodile clips are a very bad idea...cross them when connected to a 12v battery and you have enough current to do serious damage. An acquaintance of mine has deep scars around his wrist where his watch strap shorted a car battery when he was working on an engine. We are talking about being hospitalised, needing extensive skin grafts and months of physio. Apart from the physical danger, you are far more likely to get sparks which could damage electronics or connect them incorrectly.

I personally have a deep hatred of cigarette plugs...the connection that they make is rubbish and easily disturbed. I have replaced mine with XLR plugs. They are still better than clips though.

[PARTY MARTY]

Thanks kirkster501 for your reply! Your response was very helpful!

I was going to use battery clamps soldered on good quality wire to a cigarette socket, here the battery clamps would already be connected on the battery, so that there's no risk of accidently connecting the terminals at the wrong poles! The whole I'm asking that will a gel lead long cycle battery work for the QHY8L without running into problems!

[PARTY MARTY]

Thanks Zak! A very interesting point, risk of sparking is not alway's good for electronics! I think that I might throw in a ON/OFF switch into the circuit to prevent it from happening! This will only work if everything is connected properly then the switch is then applied hopefully reduce sparking!

[D_Mike]

presumably it is just running a car's engine while stationary that is illegal

so you have two other options:

1. get quite a long cable and drive around the inveter in circles, slowly.

2. ignore the rules, you're out in the middle of the night, nobody will catch you. Be a bit wild! maybe even cross the road when the red Ampelmännchen in watching too

err... sorry, i can't actually be of any real help.

[ollypenrice]

I hate cigar plugs and don't think they are serious for astronomy, where a break in the supply is such a pain. I also agree that the clips are a bad idea.

I can't see the leisure battery doing any harm as long as it is giving 12 volts. You could just test one to see what it really gives, but I think plenty of people are using them.

Olly

[Zakalwe]

I can't see the leisure battery doing any harm as long as it is giving 12 volts. You could just test one to see what it really gives, but I think plenty of people are using them.

Olly

Never , ever mistake voltage for current.....it may be the last mistake that you ever make. 12 volts it maybe, but current is what burns. Lead acid batteries are designed to dump high currents (think hundreds of amps) in a short space of time.

This shows the potential (no pun intended) for danger that a 12v car battery has (again...ask my mate that had to get bits of molten watch strap cut out of his wrist. He was lucky not to lose his hand)

http://www.ncbi.nlm....pubmed/16006850

[Zakalwe]

How to kill yourself with an ordinary PP3 9 volt battery:

http://www.darwinawards.com/darwin/darwin1999-50.html

[PARTY MARTY]

Thanks Zak! Now you're trying to scare me here!

But you have sound advice on this! I might just stick with the power tanks in the safe side, However I can't seem find any which over 17 ah, I want more power for the QHY8L!!

[Helen]

You can get a battery box for a leisure battery which sorts out the connections/on-off switches etc for you. http://www.ebay.co.uk/itm/DELUXE-BATTERY-BOX-LEISURE-BOAT-CAMPER-ACCUBOX-/181033655228 A lot of us have them and they work well.

Helen

[PARTY MARTY]

Thanks Helen! But there doesn't appear that listing is there any more! Have got other links Helen much apreitated

[Helen]

http://www.tayna.co.uk/Numax-Deluxe-Battery-Box-Accubox-P7784.html

:-)

They are common for caravanning and sailing so I'm sure you'll be able to find a local stockist.

Helen

[PARTY MARTY]

Thanks Helen! That is brilliant, you just answered all my questions, now I be looking for a big 75 ah leisure battery! My QHY8L will run for days with this battery box!

[Zakalwe]

.

[SnakeyJ]

There are some good threads on SGL about making battery boxes. I would strongly recommend using correctly rated dc fuses in line wwith any expensive equipment. Not sure of peak current draw for qhy8l, but would assume this could be quite high for cooling - you can always check the output ratings of the mains adaptors.

[PARTY MARTY]

It is exactly 5 amps on the QHY8L, so definitely I'll be fitting a 5 amp in line fuse on the battery box, I don't want to destroy a CCD which costs under a grand. It's a lot of money to burn and I don't fancy my chances trying to cut corners, at least going through the battery box way is going to regulate the power output and prevent damaging the CCD! than trying to botch wires and terminals on a leisure battery which chances of something to go wrong are high!

Thanks Helen with this awesome idea! And I'm sure it's helped many others faced the same questions as I did!

[AlistairHowie]

Thanks Helen! That is brilliant, you just answered all my questions, now I be looking for a big 75 ah leisure battery! My QHY8L will run for days with this battery box!

Bigger is usually better, but are you sure you want to go for 75Ah? That's going to weigh about 30kg.

The QHY8L power consumption is from 3.6W to 30W, depending on the TEC’s PWM power ... according to the manual. You're going to be averaging over 12V, so your maximum power usage will be 2.5A per hour or less. Just something you might want ot consider ...

[PARTY MARTY]

The weight doesn't concern me here, being member of the Army the weight issue is standard practice considering I march around 25Kg for 8 miles in a time limit of 2 hours on my back is part of my job!

Thanks Howie for the calculation you provided it's good to know some values like this, so it gives you a good general idea on how the QHY8L draws it's power, I notice when during the summer months that I use more power due to the PEC cooling fan to regulate the temperature than in winter where the fan is hardly used especially where I live -6 is the norm. M

My 20 ah dies early in summer where I can get literally 4 and bit hours use, but in winter the 20 ah runs forever!

Averaging 2.5 amp per hour is interesting, here I'm only calculating the maximum output drain, So you reckon that 75 ah might be to much? What about 40 ah instead, it's heavy at 14Kgs but as enough power for up to 2 days use, and battery is not as bulky!

[Merlin66]

A fully charged battery has 13.8V, dropping to 12V.....

There's no problem running your QHY camera directly from a nominal 12V battery , gel cell or leisure type.

I found the 20Ah gel cel batteries they use for golf buggies/ mobility scooters to be ideal!

A couple of those are easily handled and do the job well. Just remember to get a GOOD electronic charger. They will out last the powerpack every time!!

[kirkster501]

Remember there's more to power up than the CCD. The mount, your laptop (after it goes flat), dew strips etc. those four alone and your looking at well over 12 amps. Do the math..... A long session away from home and all of a sudden 12 does not go into 75 many times.....

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[PARTY MARTY]

I've ordered a 40ah battery for the battery container! Thanks Kirkster501 for your concern with the power issues! However I was just purely going to use the 40 ah battery for the QHY8L CCD, my NEQ-6 mount will be powered by a 17ah Power tank. And all my Dew heaters are powered with a 7 ah Power tank! I never really liked to save power connections on one battery, particualy the QHY8L which if you share the power with the mount, QHY8L produces some interference in the images where you get a power loop problem, Here you see a Red to green faint banding formed on the images! That's where there isn't much voltage supplying the CCD! I've stop this and now I use each serprate power source to each devices now! Only problem you end up carrying 3 batteries for one imaging telescope rig, but you'll get used to it!!

[AlistairHowie]

Dion over on Astronomy Shed had the same ground loop problem with his QHY8L, you can check out his youtube videos of it.

I'd say you have more than enough juice for your setup. Your mount consumption is negligible when tracking. The killer is a laptop if you need to charge it.

[PARTY MARTY]

Thanks AlistairHowie! The power issue with the Laptop is not problem! I use a Net book which a ASUS Eee PC 1.6 Ghz duo processor and runs on 2 Gb of ram, this small laptop is ideal for capturing images and can quite happily run PHD Guiding software for the QHY5v and EZ cap for the QHY8L, despite being a £200 net book it's the best buy I've ever bought I.T wise for a long time, This net book can run and run on it's own battery up to 11 hours use, which shows that these net books are pretty good! Only drama I have with it is that the Net book is not powerful enough to serious work on Image stacking and processing with Deep sky stacker and Paintshop Pro X5. So I transfer all the captured images on a memory stick and transfer them to much my much bigger and powerful Sony Vaio PC which handles the rest!

So if anyone is wanting a small netbook to be used for capturing images, then get an ASUS Eee PC they are fantastic for the price! And they have fantastic battery life and it save on bringing your much powerful laptop at and risk damaging it, here the Eee PC would be easy to replace! I've had mine for 2 years and it never let's me down!!!