Goto power supplies

[newt]

Another noob question sorry.

Hope to order a skywatcher 127 mak(goto) tomorrow and I know that i'll be able to get by on batteries to begin with but is the skywatcher power tank really worth 100 notes!!!

Does the scope come with a lead to connect it to an external power source? and if yes, wouldn't it be cheaper to buy a deep cycle gel battery and charger, a quick google search found a 20ah(bigger than powertank) battery and charger for between £50 & £60!!! or will I need some sort of oddball connection that only a power tank can provide?

Thanks

Dean

[umadog]

Powertank is over-priced and has QC issues. Most in the know use the deep-cycle batteries you describe.

[rowan46]

maplins do the gel battery power packs a lot cheaper. the people who get them use them because we don't have to bother making boxes and wiring in sockets etc

[newt]

Thanks guys, maplins do a 17ah portable jumpstarter, which I don't think will ever come close to starting my van, but sounds perfect for running two small dc motors in a goto mount and all for £30! far better that £100 for the powertank that has the same size battery!

Dean

[rowan46]

don't forget with gel batteries they need charging after every session and once a month if you are not using them

[Horus]

Thanks guys, maplins do a 17ah portable jumpstarter, which I don't think will ever come close to starting my van, but sounds perfect for running two small dc motors in a goto mount and all for £30! far better that £100 for the powertank that has the same size battery!

Dean

I bought one of those from Maplins last week, seems a well made piece of kit for the money

[Dave S]

Don't knock the power tank too much.

I bought mine for £54, the build quality is fine and it also has several multi voltage sockets which power the camera, laptop etc... as well as the mount. I have found both the 800,000 candle power lamp and the red light extremely useful too.

Dave...

[russ]

The Maplins 17Ah Powertank is good if you treat it right. I bought my first in 2003 and it died in 2010......not bad at all. It also started a car once, which i was amazed by. Thought that part of it was just a gimmick and would never have the juice for that. But it did. Only a Toyota Yaris though.

[brantuk]

Yup - the maplins power packs will start a car if you use them right. I had a flat battery at Kelling last autumn and it got me going nicely (my maplins 17ah one) in a Volvo Estate.

After connecting it - wait 15-20 mins to let both batteries equalise - then you have enough in the car battery to turn the ignition on and fire up

[Carbon Brush]

A caution on charging the Maplin box. I know someone who bought one for astro use. The supplied mains charger output something like 19V on low load. Enough to eventually gas the sealed battery to destruction if left connected long term. Just charge it till it comes up to 13.8V then turn off.

[Watcher]

I have the same scope, it does eat AA batteries, 8 at a time. I bought the Skywatcher tank for about £50 but wished that I had shopped around as it only has the 12v output. To answer your question, the connector is nothing special. If you are only observing at home then you could consider a decent extension lead and transformer. I have a JCB waterproof extension lead which I bought from a DIY shop. It's waterproof and comes on a spike so you can stick it in the lawn. This seems to be the same one: JCB 5mtr 13ampTwin Outdoor Socket with Spike from ValueLand

[newt]

thanks watcher, i just started another thread with a more scope specific title but you have put my mind at rest now, i had visions of having the scope and maplins powertank and not being able to connect the two together!

[Blackelvis]

Hi all,

I just got my telescope and, being keen, I've already gone through 8 batteries. Going to maplins and picking up the following:

3in1 Portable Jumpstarter : InCar Battery Chargers and Compressors : Maplin

Is this what you are discussing? Also how do you properly hook it up?

[newt]

Hi all,

I just got my telescope and, being keen, I've already gone through 8 batteries. Going to maplins and picking up the following:

3in1 Portable Jumpstarter : InCar Battery Chargers and Compressors : Maplin

Is this what you are discussing? Also how do you properly hook it up?

Yes thats the one. I'll be picking one up on the weekend, running on an extension lead from the house at moment as haven't ventured beyond the garden!

As for connecting I'm hoping maplins sell a suitable lead with a 2.1mm tip positive plug one end for the goto and a car cigarette lighter plug on the other which will plug into the power tank. Although I think eventually I'll end up making my own lead. You can buy suitable parts from RS.com and then make the cable nice and long to allow for getting wrapped around tripod, and use a fused plug too.

Dean

[Blackelvis]

Yes thats the one. I'll be picking one up on the weekend, running on an extension lead from the house at moment as haven't ventured beyond the garden!

As for connecting I'm hoping maplins sell a suitable lead with a 2.1mm tip positive plug one end for the goto and a car cigarette lighter plug on the other which will plug into the power tank. Although I think eventually I'll end up making my own lead. You can buy suitable parts from RS.com and then make the cable nice and long to allow for getting wrapped around tripod, and use a fused plug too.

Dean

Hiya Newt. you reckon this is suitable? Universal 3A DC Power Supply : InCar Power Adaptors : Maplin

[Nibor]

An interesting thread for me as I am looking at the same GOTO system - would I be correct in thinking that straightforward rechargeable batteries would be an option?

Has anyone any experience of the staying power of rechargeable batteries (provided they are compatable of course)?

Given compatabilty and a reasonable battery life then two sets of batteries should suffice - one on charge the other in the GOTO unit.

Has anyone done this successfully??

[rowan46]

An interesting thread for me as I am looking at the same GOTO system - would I be correct in thinking that straightforward rechargeable batteries would be an option?

Has anyone any experience of the staying power of rechargeable batteries (provided they are compatable of course)?

Given compatabilty and a reasonable battery life then two sets of batteries should suffice - one on charge the other in the GOTO unit.

Has anyone done this successfully??

rechargeable batteries don't work too well in go to's an alkali battery is charged to 1.5v a rechargeable battery to 1.2v

[x6gas]

My plan was to use 2 x 6 volt SLAs wired in series so that I can tap the first cell to power my autoguider (which needs 6 volts ideally) and both cells for the GOTO. Any thoughts on whether this is sensible?

Right now I am a garden observer so it's a JCB extention cable for me!

[RogerTheDodger]

If you are using mains electricity outside USE AN RCD! never mind what fuse, you'll be dead before it blows.

just to check you heard me USE AN RCD!

[x6gas]

If you are using mains electricity outside USE AN RCD! never mind what fuse, you'll be dead before it blows.

just to check you heard me USE AN RCD!

Don't worry, socket protected as is extention cable.

Given the condensation that builds up on everything it's pretty much a must!

[Donkeiller]

As well as the gel battery you can buy the tip positive jack connector and suitable cable from Maplins for a couple of pounds (I did). Then a bit of soldering and your away.

Alternatively you can always snip the cable and connector from the supplied battery pack and connect it with croc clips to the gel battery - which also acts as great stabiliser for the AZ Synscan Goto mount.

[newt]

I was extra cautious when i got my 3 in 1 starter from maplins, and also got a cigarette lighter plug with a 12v regulated supply output. It was only about £8. I was a bit concerned that just connecting croc clips to a battery and then straight to the scope could put a higher voltage direct into the scope and damage it, i.e. My 3 in 1 unit shows nearly 14v when fully charged. Prob just me being uber cautious but may be worth considering if you plan on using a large lesuire battery!

[Carbon Brush]

Hi Newt.

A '12V' lead acid battery actually does show 13.5 (or a little bit more) when fully charged and not loaded. I'm sure the scope control makers know this and take account in their design.

If you look around, a lot of '12V' bench supplies for equipment actually output 13.8V or thereabouts to reflect the voltage seen from a fully charged battery. So nothing to worry about scope-wise.

The problems often come with overcharging a lead acid battery because the cheapskate company who supplied the mains charger have provided anything up to 20V, which will gas the battery if left on for too long. Then of course you might be tempted to connect the 20V charger to your scope with expensive results.

Hi X6gas.

If you take a different current from each of your 6V batteries, which your proposed connection will do, then you must charge them seperately. NOT in series from 12V. If not, you will end up with one 6V block overcharged and venting, while the other is still part charged.

Hope this is useful.

David

[Defender]

I'm a total noob when it comes to electricity, i've just found my old jump starter (just a cheapy), it has 2 clips for starting cars and a cigarette lighter socket, i thought the cigarette socket was only for recharging the unit but it also gives power i found out last night, does this sound like it would be adequte to run a goto mount?

[bcfcciderhead]

Hi Newt, i use that power tank (also from maplins) to run my skywatcher goto, and it works very well, also starts the car (diesel mondeo) the kids also worked there nintendo ds of it when camping last year.

FLO selll the correct lead for it to which i bought, very long and about £10, well worth getting, it has the ciigarette plug on the end and is fused.

Defender, i cant see why not, but check the output will be the same as what the goto needs.