Month: December 2022

Since the 1990’s I have used Sealed Lead Acid batteries for powering my astronomy and astrophotography equipment.

When I was routinely using a laptop in remote field locations I was using at first a 40Ah SLA battery and then later a 120Ah SLA battery which was left in the boot of the car, a cable running to the telescope and other equipment such as laptop, USB devices, dew heaters, etc.

Curiously, for my portable rig the power demands have reduced in recent years. A combination of location and type of imaging. Running the mount with a small modern auto guider and someone else’s DSLR doesn’t require very much power. These sessions usually run for less than 4 hours which means a laptop can power its self for that time, no need for external power. Also in more recent years the need for battery power has reduced. Often my workshops are located at my private dark sky observatory where I have mains power, or at the Perth Observatory where I have mains power. If I’m not imaging there, then there’s a good chance I’m using my permanently mounted rig instead, that of course runs of mains power So, in recent years my power requirement had dropped to a 9Ah SLA battery.

Looking forward to the 2023 Total Solar Eclipse in Exmouth, and wanting to up the level of functionality in my workshop telescope rig, and looking at needing to buy a new 9Ah battery due to degradation of my existing, had me looking at alternatives which would be sufficiently over-specified they would provide for almost any workshop scenario.

The new astrophotography lithium battery

I hunted around for a light weight high capacity battery and came across https://www.auspowerbanks.com.au/

I’d seen a whole world of modern battery options, moving ahead from a simple battery with two terminals that I would need to DIY connections for. This is the direction I wanted to go.

I ended up choosing the “Outdoor Power Bank – 96000mAh (Solid Black)” pictured above. This large battery weighs only 3kg but packs a huge amount of power. It has dual cigarette lighter style outlets. it has various USB outlets.

I plug the Losmandy and ZWO ASIAir Plus directly in to the two 12v sockets. Sometimes the USB is used for powering the Prima Luce ESATTO focuser when I have been using that. I regularly have an iPad or iPhone plugged in to the USB outlets.

I have occasionally powered my Dell XPS15 laptop off the unit via a 240v inverter and the laptop’s supplied power supply.

The lowest I’ve had the battery so far is 2-3 bars out of 4, about 50-60%. The battery has been 100% reliable. The length of time it lasts combined with being Lithium type battery means I have no concern about running out of power and only charge it now and then, not after every workshop even if my workshops are weeks apart.

The unit has a bright diffused light on one end which has occasionally been useful for floodlight of a workspace to find lost screws and such on the ground.

The only thing I wish is that it had built in AC charging. It’s a shame I need to carry around a 12v power supply plug pack to charge the unit when I travel remote. That said, it’s taken only for caution because even a full weekend this unit will not run out of battery power for me.

More Blogs

This is part of a blog series regarding my updated workshop telescope rig

With my recent purchase of the SkyWatcher Quattro 8″ (200mm) and the upcoming Total Solar Eclipse in April 2023 it’s time to test out the Baader solar filter for the 200mm aperture.

Why Baader Solar Film?

I’ve consistently found Baader solar film provides a higher resolution more detailed view of the moon than glass white light solar filters. All the glass solar filters I have looked through, have not produced as much detail by some noticeable amount.

You do need to protect any solar filter while in transit/storage well. Any scratch, hole or other defect could risk damage to your eye or camera. One thing which people prefer about glass filters is they feel that the glass is more durable than the solar film. I can imagine a glass plate may well handle an object impacting it better than the solar film would. However I have used the solar film for about 20 years and so far have no defect in any of my filters. I keep the filters stored well in boxes such that the film is not in contact with any surface but is protected from impact.

I purchased a Baader OD 5.0 Astrosolar Telescope Filter from https://www.testar.com.au/

Equipment

This is setting up the Baader filter.

Mounting on the Telescope

The Baader filter slots over the front aperture with rubber coated pegs which grip against the outside (or inside if you configure it as such) of the optical tube. It also has Velcro with self-adhesive patches to prevent it coming off if the rubber grips were to be insufficient.

Here are some photos of the Baader filter on my SkyWatcher Quatro 8″ (200mm):

Solar Photos using the Baader solar filter

So, it turns out the only problem in taking photographs using this filter on the Skywatcher Quatro 8″ is brightness – too much of it. At raw prime focus the Canon R6 I had mounted on the telescope at the time of testing was using 1/8000th second exposures at ISO 200. Anything slower and the images would risk over exposure. I am likely to use a barlow or teleconverter lens with this configuration in reality, and doing so will dim the brightness (2x barlow will approximately half the brightness, for example). If that was not sufficient then a aperture mask could be made to shade some of the filter/aperture.

The clarity and detail lived up to the usual Baader solar film quality and did not disappoint. Here is a sample exposure which is a single exposure without stacking or any editing than brightness and clarity in Lightroom):