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If I have one solar panel, and four 12v batteries I need to be charged, two pairs of equal age and capacity (60 amp hour x 2, and 50 amp hour x 2) and the pairs have the same resting voltage and seemingly the same capacity, and I can get a solar charger unit which can charge two batteries (see link below), I was thinking of charging each pair in parallel.
I've read about the risks of charging in parallel, with the weaker battery having the dominant impact and bringing the other battery down to its capacity, but in reality, how likely is this to be a problem in the course of 5 years, where the batteries won't be used that much anyway, maybe discharged 20%, just 10 times a year?
I'm conscious there is scope to discuss lots of things around this, like "buy pairs of new batteries rather than starting out with old ones" and "buy larger capacity new batteries etc", but this is the set up we have and will be sticking with.
Thanks for any replies.
I'm tempted to go down the route of getting myself a brand new reflector... My friend's old Meade 114/900 is a good telescope, but I want something of my own and with a bit more light gathering power. To this end, I've been looking at a couple of different models and manufactures.
I must admit, the Skywatcher Explorer 130M floats my boat, as it's motorised with a speed controller.
Any thoughts or observations?🤔
So I had a free day yesterday and decided to sort out my equipment and update my astro laptop software packages. I downloaded the latest Stellarium and managed to get it to sync with APT. I installed my Xmas present from my sweetheart (Optolong L-eNhance filter) how did she know it's what I wanted??? I recently installed the free trial version of Pixinsight on my main laptop so after watching a few YouTube videos decided to get some Dark and Bias frames to create some masters ready for my next session.
The weather was good yesterday and it stayed clear here as the sun started to set, so I set everything up outside hoping the apps were wrong and it wouldn't get cloudy. As it got darker I launched Sharpcap and completed a polar allingment, I used Stellarium and APT to slew to Vega and checked the focus was good. I then used Goto++ in APT to slew to NGC 7380 (Wizard Nebula), I set PHD2 off guiding and then I had my first issue; my laptop would not connect to my Lyn Astro dew controller so I manually set the temperature to quite low as it wasn't too damp at that time. So I started capturing 5 minute subs went inside and remoted into my astro laptop from my main laptop to check how it was going, all appeared good.
I recently set up a Rpi NAS at home so I'm able to transfer data to it and then to my other laptop on the go, so after I'd got a few subs I opened them in PI to check the quality, they looked ok to me. after about an hour PHD2 started binging a lost star warning so I went outside and the clouds were starting to cover the sky, I then took loads of flat frames using my main laptop, Notepad and 3 sheets of white paper and decided to take some more darks in case it cleared. I then set about trying to process the 9 subs I'd managed to capture with the 200 flat frames the master bias and dark frames I'd created earlier. Despite the lack of subs I'm quite pleased with the result, I have done a quick Histogram stretch, and the knowledge I have gained, I'm definately going to purchase PI when I can afford it.
So this morning I thought I'd sort out the issue with the connection to the Lynx Astro dew controller, you won't believe it, my Astro Laptop will not turn on, it's been playing up for a while I suspect the battery has died. So just when I thought I was getting on top of this frustrating hobby I get another spanner in the works. So do I gamble and order a new battery then discover it is the laptop that has failed, do I set up another old laptop I have and hope it will be ok, do I set up my Rpi3 with Indigo or do I buy a mini PC as I know my way around windows?
Anyway here's the calibrated stacked image as it is in PI with a quick stretch.
I've finally got around to making my flats box.
I decided to go for a cylinder rather than the normal square as I thought it would maximize the amount of reflected light and limit any 'dead' areas. I could also use the Celestrons dust cap retaining pins to lock the flats box onto the 'scope.
I purchased some of the craft board that has a thin foam sheet sandwiched between two sheets of thick paper/thin card. In order to bend the card into a cylinder, I creased the board every 20 mm by pressing the edge of a steel ruler into the board. It took two of the sheets to make a cylinder big enough to fit my C9.25, with only a couple of cm trimmed off.
I then made a reinforcing ring/defuser holder from two strips of the foam board; this time creasing them at 15mm intervals. I stuck these level to the bottom edge so the joins were 90° to the main cylinder joins. These strips were cut wide enough to ensure that the diffuser cleared the secondary housing.
The cylinder was designed to lock into the C9.25s dust cap retaining pins so next I cut two keyways into the bottom outer side. They looked a little weak so I reinforced them with some Christmas chocolate reindeer plastic packaging!
Although the foamboard is quite shiny, I wasn't happy with all the grooves, so I lined the inside with white A4 paper. The Perspex sheet was cut to shape and hot glued into place onto the ledge.
Next, starting at the top, I notched the edge of the cylinder to run the LED string lights cable through and then started to spiral the LEDs around and down the cylinder.
The top cap/reflector was made from two discs of foamboard. One to go inside the cylinder and one to sit proud of the edge. They were glued together before being hot glued onto the top of the cylinder. The LED light string that I bought has an integrated on/off button as well as both up and down brightness buttons with a 3M sticky pad on the back, so I stuck this to the top cap.
As I had previously made myself a 'scope mounted power distribution box with aircraft sockets for power, I removed the 3 pin UK plug/ac-dc converter and soldered on an aircraft plug to match my 12 volt DC supply socket.
The lightbox illuminated.
Celestron C8 XLT + extras and SkyWatcher Star Travel 80 (ST80)
I have a Celestron C8 with XLT Starbrite coatings. Will include the full length base plate, both visual and imaging backs, scope rings, front 8" end cap and the finder scope with it. No box I'm afraid. Optics are good and clean, focal length is huge - 2300mm from memory. This lot would cost close to £1300 new and one with less spec went for £750 on fleabay recently. Might be interested in a part exchange or will let it go for £450 collection only.
Also, I have a SkyWatcher Star Traveler 80 - good optics, used as a guide scope - just the scope itself (does not include the barlow in the photo) - now including dovetail bar and scope rings looking at around £50 for it.
I have decided to save up for another refractor, WO, Equinox or even toward an Esprit. However, I would also consider p/ex for an Intel NUC and/or Pegasus Astro Pocket Powerbox.
Please excuse some of the colours - I used my astro modded 6D which was in the observatory so the "nice" purple is actually black !!
Both these are collection only.