Celestron 7 amp power tank

[goodricke1]

Can anyone suggest the best UK supplier for this purchase, surprisingly FLO don't seem to stock them...?

Thanks.

[alanjgreen]

The sky watcher one is the same thing, Just rebadged.

[alanjgreen]

http://www.firstlightoptics.com/power/skywatcher-powertank-7ah.html

[DirkSteele]

To be honest the branded powerpacks are expensive for what they are. For only a few pounds more, you can get a 17amp hour pack from Maplin which also has a inverter for mains power. Bearing in mind that you should avoid running a lead acid battery below 50% capacity too often, you effectively have to half the amp hour rating of any powerpack you see.

http://www.maplin.co...le-power-224871

EDIT: To be even more honest, the large capacity leisure batteries are far better value still. Take this one for example (http://www.batteries4leisure.co.uk/battery/Numax-Sealed-Leisure-Battery-100Ah-LV26MF/42/?gclid=CPXrrI6Sr7cCFbMbtAodtnYA-A) 100Ah and £67.

[goodricke1]

Thanks for replies guys.

Dirk, I think I read elsewhere that some of those Maplin tanks may lose reliability, although on second thoughts it could be have been jump starters I was reading about... anyway I don't expect my observing sessions to extend beyond a couple of hours so hopefully the 7 amp will suffice (and I'm running low on readies also!).

I thought the Skywatchers were a Meade brand and might not be compatible so thanks for correcting that Alan.

[LukeSkywatcher]

I have two Celestron 7Ah power tanks. They are uuber over priced for what they are. You are paying for the name. Get yourself an unbranded one that is stronger (17Ah etc) for a fraction of the price.

Maplins really seem to be the popular choice.

[gkec]

I have a SkyWatcher (same as the Celestron) and a Maplin power tank. The Maplin one is far better in that it has more capacity and you can charge and use it at the same time (so if you have a power socket available you don't have to unplug everything to switch between battery and mains) and cost less.

[goodricke1]

Well thanks for the suggestions, if I had searched properly I would have seen this was discussed only a month ago, so apologies.

[gkec]

Well thanks for the suggestions, if I had searched properly I would have seen this was discussed only a month ago, so apologies.

http://stargazerslou...ed-help-please/

Don't worry about it. The consensus on power supplies is fairly consistant.

On the other hand if you had you asked what telescope to buy...

[willhick]

With Regards to the Maplin Powerpack http://www.maplin.co...le-power-224871 does this come with a cigar-lighter plug to a 2.1 mm centre positive dc jack to suit Skywatcher and celestron mounts or does this have to be purchased separately ?

For example from FLO http://www.firstlightoptics.com/astronomy-cables-leads-accessories/skytron-power-supply-cable-for-skywatcher-celestron-mounts.html

Cheers

[midnight_sky_watcher]

Unbranded are certainly a lot cheaper, I have 2 sky watcher tanks, way over priced for what they actually are.

[hazegood]

With Regards to the Maplin Powerpack http://www.maplin.co...le-power-224871 does this come with a cigar-lighter plug to a 2.1 mm centre positive dc jack to suit Skywatcher and celestron mounts or does this have to be purchased separately ?

For example from FLO http://www.firstlightoptics.com/astronomy-cables-leads-accessories/skytron-power-supply-cable-for-skywatcher-celestron-mounts.html

Cheers

I have this power tank from Maplin http://www.maplin.co.uk/3-in-1-portable-jumpstarter-383992 the supplied lead to recharge it from a cars cigarette lighter is 2.1mm and tip positive, works fine using it to supply my skywatcher AZ Goto mount.

or if your handy with a soldering iron, you can buy the parts from Maplin for less than a fiver and make your own lead

[willhick]

Thanks for answering my query, a great help. Looking good for clear skies tonight

[goodricke1]

I have this power tank from Maplin http://www.maplin.co...pstarter-383992 the supplied lead to recharge it from a cars cigarette lighter is 2.1mm and tip positive, works fine using it to supply my skywatcher AZ Goto mount.

So can I confirm that the supplied lead can actually power the scope and is not just for charging the tank...? And also, is it possible to 'overcharge' it, in the manual it says 10-18 hours but the guy in the shop said 40 hours Thanks again.

[Carbon Brush]

The generic answer on charging is measure the voltage on the battery.

Usually the staff in High St retail outlets do not understand lead acid batteries.

If you charge at 13.2V to 13.8V the charge current will reduce as the battery approaches full charge.

With this regime the charger can be left on indefinitely without harm.

My shed alarm uses a 12V battery with the float charge described above. It is sometimes left on continuously.

Every few months I turn off the charger and deliberately discharge the battery to check capacity.

All is well 5 years on. The battery has lost some capacity over this time, as expected, but is still in good condition..

If the charger provides more than 13.8V then you risk overcharging the battery.

It is up to you to turn off the charger. Yes I have seen several start n charge or powertank type products with this design error.

If you overcharge, the cell will vent a hydrogen/oxygen mixture in exactly the right proportions for an explosion if there is a hint of spark.

If the battery manufacturer fails to fit a decent vent, then on overcharge the battery case can split, spraying corrosive gel over the inside of the powertank.

When the battery fails -they all fail after a time, then don't skimp on the replacement.

Go for a known name. Look up the manufacturer's (not retailer) web site.

Stick with a battery specialist. Not the wishy washy company from China.

Hope this is useful. David.

[gkec]

Don't buy the Skywatcher/Celestron ones they are over priced and not as good as the Maplin ones. If you wreck a Maplin one, which I haven't yet, but I have wrecked a skywatcher, then it is not too expensive too replace. Also with the Maplin power pack I have you can charge it as you use it.

[glowjet]

Another alternative to consider, is to just buy a good quality sealed lead acid battery, such as Power-sonic, which do not deteriorate, if not recharged after long periods non use. A 7Ah is, I believe, not much over £10, mount in a small box, wire to a socket or a couple of terminals of your choice, job done. You would ,however, need to purchase a dedicated charger, but these can be had I think for something less than £20

[goodricke1]

Thanks for those detailed replies. I've decided to charge it up for the full 40 hours and, if things don't work out, well it's been nice knowing you guys