Battery Packs for Goto scopes

[Bavchouhan]

Hi All I'm looking for a battery pack for my goto scope, now looking at what is available for my skywatcher, they offer a battery pack which is lead acid. Having worked in the photo industry for many years, I understand that lead acid has its advantages and disadvantages. mainly of building memory effect s, weight etc. Are there alternative power packs to look at that use lithium ion//polymer technology, this will obviously reduce the weight but also no memory effect on the battery. has anyone had experience of using a lithium battery pack, how does it fair? Thanks all

[knobby]

Have a look at golf trolley packs... Expensive though!

[LeeB]

Hi , i've had a try with a number of different battery techs, lead acid, Nicad, dry cell, NiMh, lithium ion and lithium poly. They all have pros and cons. For price,capacity, Toughness, cold performance the lead acid is hard to beat. The only big down side is weight. The battery memory effect everyone talks about is a bit of an urban myth. Batteries lose the ability to hold charge after cycling many times and some techs have low discharge thresholds that need to be stayed above or they get wrecked. Also lithium needs charging in a different way in that the volts can't exceed a set level or fire/explosion occurs so the final charge does'nt delta peak it amp reduces. I have built nicads and nimh for years for radio control racing and even those, famous for memry effect can be reconditioned using the correct charging methods. If i was to guess at the next wave of batteries for scopes it would be lithium polymer but they can be dangerous, especially if shorted or got wet. I have had two fires and one big pop during my rc flying, they are nasty when they do go.I have a 5 amp pack that I have tried with thye scope but matching voltage is difficult as each cell is 3.7volts nominal (3 would give 11.1 volts or 4 would give 14.8) so not ideal for a 12v usage.

To recap i use a 12volt booster pack (a mac one) mainly heavy but rock solid. tons of amps and with an attached charge level indicator and my eq6 will last all night, probably two.

[LeeB]

as an aside you can use the weight to your advantage , if your tripods a little light make a cradle for the battery and use its weight to add stability.

[DanH]

As the 10Micron needs 24V, I had to build my own battery pack.

I'm using 2 Panasonic 22 amps/hour gel batteries serially connected, fuse, switch, digital voltmeter.

I added a second circuit with fuse, switch and 24V->12V converter.

This gives me 24 and 12V outputs, independently switchable. The 12V output beeing needed for some of my accessories, like the flat screen.

I placed the whole lot in a marine battery box, the complete set weighting 15.5kg

[E621Keith]

... The only big down side is weight....

Actually, engineers at IOptron has turned it into a big advantage.

http://www.altairastro.com/product.php?productid=16567&cat=273&page=1

[DanH]

Looks nice, but only 8A/H !

[Matt Scunthorpe]

If your just driving your mount, have a look at this

http://www.maplin.co.uk/5-in-1-jump-starter-with-portable-power-224871

I bought it on advice of people on this forum, and a friend who has a NEQ6. I tend to charge it every 2-3 times i go out (but obviously depends on how long your out for etc).

Plus its handy if you ever need to jump start your car or pump up tires.