Mars Power

Wow.  Three and a half inches of rain in the past 24 hours.

That is a lot of rain for central Virginia.

The astronomy forecast for the remainder of the weekend doesn't look good.  There may be a brief window for viewing Mars tomorrow morning, but I'm not counting on it.

Shoo, clouds!

So, in lieu of fresh images of Mars this weekend, this post is going to feature some of the equipment that I use during my driveway astronomy sessions.

Specifically, what do I use to keep everything powered during an all night session?

Most importantly, I must be sufficiently powered to stay awake all night.  I rely heavily on this piece of equipment, my stainless steel coffee mug.  It loses heat at just the right rate, keeping the coffee warm long enough for the entire cup to be consumed at an enjoyable temperature.

Guatemala Antigua preferred!

For the electronic equipment, I originally started with this, a simple, but lengthy, extension cord.  We've had this forever and keep it un-kemptly coiled in the garage for ready access to power whenever we need it out of doors.

Fifty feet of power source!

I would unfurl the cord into the driveway and plug the 12v DC converter into it.  It is a beefy power supply that I use for amature radio gear.  It is a linear power supply and weighs about twenty pounds.

Plenty of DC power!

This combination worked nicely, but the cables had a tendency to get wrapped around the telescope within an hour or so of skygazing.  Once, the telescope actually wrapped the cord tightly enough to pull its plug out of socket.

It was then that I started accumulating batteries.

This one is my favorite. It is simple to maintain and has never run out of juice.  It is a TalentCell rechargeable lithium ion battery  It provides 12v at 8300 mAh.  I use it to provide power to the telescope's electronics and motors.  It is lightweight so I just let it ride on the bottom of the dob's base as I use the telescope.  This is perfect practice to avoid tangled power cables.

TalentCell Rechargeable 72W 100WH 12V/8300mAh Lithium Ion Battery Pack

Note the "C" label on the battery.  There is a corresponding label on its charger cord.  Clever, huh?! 🙂

I'm also fond of this one.  It is an XTPower rechargeable lithium ion battery  It provides 12v at 2000 mAh and 5v at 2100 mAh.  I use it to provide power to the focuser's electronics and 12v motors.  It also provides 5v power to the Bluetooth interfaces.

XTPower MP-10000 External Battery Pack

The angled flap is made of black electrical tape.  I flip it down to cover the annoying blue "state of charge" LEDs.  This battery also rides on the base of the dob.

The next battery is one that I use to provide power to the astronomy laptop.  The laptop has its own internal battery, of course, but it only keeps the laptop operating for a few hours.  There have been a few times when the laptop shut down due to low battery long before I was finished with my astronomy session.  This battery solved that problem.  It keeps the laptop fully charged for over 10 hours!  It is a Poweradd lithium ion polymer power bank.

Poweradd Pilot Pro 32000mAh Power Bank

It provides 118.4 Wh and is almost as heavy as the laptop!  Fortunately, I have a wheeled cart dedicated to the laptop and battery.

Cold weather tip:  Lithium ion cells lose performance in low temperatures.  When I use these in cold weather, I wrap them in insulating sleeves.  The heat they generate when discharging keeps them warm enough.

Next week?  Clear sky and more Mars!