I ended up going for the Celestron PowerTank Lithium Pro because I got a deal on it and it meets the compactness, lightweightness and versatility criteria. And there were some good reviews out there, with some caveats.
So what have I ended up with?
A LiFePO4 battery with two USB's - 5V, DC quick charge and fast charge, one of 2.1 A. A 12v DC 10A car battery adapter port (which should provide consistent power) and a 12V DC 5A telescope power port. There is a LED panel with white or red light illumination. The battery shuts off automatically when insufficient current flow is detected. So there shouldn't be accidental battery drain. I immediately like the nifty 2" strap that helps secure the unit to a tripod leg and I suspect I'll use the red light to illuminate the ground so I dont keep bumping into the tripod legs in the dark! And I can definitely confirm it is lightweight relative to its size - so bonus!
The PowerTank holds up to 2000 charge cycles, has an un-recharged shelf life up to 10 years and should go for up to 17 hours. LiFePO4 batteries tend to be safer and less prone to chemical fires or leaks than traditional lead-acid and other lithium based batteries. Tough plastic exterior, charging time of six hours (more about that later). It comes with a universal plug 100-240v AC charger.
Other things? Battery capacity is 158.74 Wh; charging input 16VDC@ 2000mA. The telescope power port is 12VDC @5000 mA, tip positive. The car battery adapter port is 12VDC @10A, tip positive. USB charging port 1 output is 5VDC@2100mA whilst the second usb port is 5VDC quick charge.
Celestron information suggests that the auto shutoff threshold current is car battery port - Less than 420mA for a long period of time.
The PowerTank has a weatherproof/dustproof rating - IP-65. The tank comes with a 2m long telescope power cord for celestron telescopes.
Finally, product dimensions? 8.75" x 6" x 4" which in my head as a European - around 22cm x 15cm x 10cm. Weight is 4.5 lbs - which at a push in my head is 2 kg's just a tad over!
So, I'm looking forward to using this, having read positive reviews.
So, having used it three times, how is it doing?
Not good to be honest - I'm mildly 'initially disappointed' given its cost!
I used the little 12v port on one side to power the mount and the cigarette socket to power the ASIair and guidecam. I plugged my DSLR dummy battery into one of the USB slots.
The good:
1. It is very compact and lightweight
2. Over three different nights - it powered everything with no problem - DSLR, ASIair mini, ZWO 120mm mini guide cam, EQM 35Pro mount. Four hours on each of those nights.
3. It will strap to a tripod leg - with some adapting - see below
The bad:
1. plastic lid - it snapped off on the second night. The two lug hinges holding it in place are poorly designed. I didn't manhandle it in anyway, no excessive force. The lid just snapped off the lugs when I lifted it up. Subsequent internet browsing shows some reviewers complaining about this! The lugs disappeared down their holes. The lid snapped on the second night - how ridiculous!
2. charging times - yes it takes 6 hours, but! Mine just doesn't seem to hold its charge. Even after six hours and all red lights show battery full, if I come back three hours later - its down to three lights and needs charging back up to get all four red lights. I am disappointed. I am switching it off correctly. It is baffling and immensely irritating. Maybe I have missed something in the handbook but I've been through it twice. Do I have a fully charged battery? 75% charged? What is it - does it automatically drop to three lights as soon as you switch it on? Silly design flaw if it is!
3. Insufficient power for DSLR camera. This is an interesting one - I use a dummy battery on my Canon 800D and when I plugged it into the USB slot on the powertank, it did power the camera but I lost the rear screen touch screen function. Just wouldn't do it at all. Use a small powerbank and all was fine. Return to using the powertank and immediate lost camera screen touch function. Back to little powerbank and back it came. Baffling but definitely related to the Celestron Powertank in some way but no idea how or why. It may be something I'm doing in fairness.
The ugly:
3. attaching it to the tripod leg with the Velcro strap. My experience? For three consecutive nights, all it has done is slide down the tripod leg. Useless! It doesn't matter how tight you do it, there is insufficient grip in the V groove to secure it and the velcro strap is just too long for a 1.75" tripod leg. I am having to use a separate little long velcro cable tidy to support the weight of the powertank via the eyepiece holder which braces the tripod legs. Irritating!
4. the LED lights are very bright. Even the red light is bright and whilst I can see its superb usefulness in an emergency, for astronomy, it does see somewhat counter-intuitive, but that could just be me I guess. It certainly lights up the tripod legs though!
I am torn between contacting the dealer I got it from, contacting Celestron to get answers to my doubts and just sticking with it and giving it a longer testing time, so that at least I am fair in this review. Let's just leave it at 'initial impressions are mixed'!
But the fact that the lid broke under barely any pressure and the fact that it never seems to reach a full charge that actually holds - seem to be major issues to me!
I'll let you know how I get on. Out of fairness, I feel the need to give it further testing.
Video reviews:
No comments:
Post a Comment