I just acquired s meade etx 125. It take 8 aa batteries but I would rather have more power. It's better to have too much juice than not enough. I have seen meade have a 17 amp power supply but cannot find it anywhere. I have also found celestron make a similar product. Does anyone know if a celestron power bank will work on an etx125?
meade etx125 power supply
Posted 04 October 2019 - 06:28 AM
Yes it will. Basically its identical to the meade one with different badges. Any 12 volt battery pack or car jump starter will work fine with the right cable. I use the smaller version of the celestron.
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Posted 04 October 2019 - 07:55 AM
Obviously, the ETX is designed for 12 volts. What is not so obvious is that many, even most automotive 12 volt items are designed for about 14 volts. Yes, they say 12 volt, but 12 volt automotive isn’t really 12 volt. I have a new “mini starter” battery that is 17 volts. I will not be hooking this to my ETX to see if it will burn it out, so I can’t say for sure the ETX couldn’t take it. What I will say is to make sure your voltage is close to requirements or you are taking a risk. Even a two volt difference is 15% over stated requirements.
Posted 04 October 2019 - 09:21 AM
I use a small Lithium on my 105, depending on the battery model should be good for 3 or 4 hours - thinking the 6800mAh ones.
Here they come with charger and a 2.1mm output lead so had to make up a simple converter as the Meade is I think 2.5mm.
You can get bigger then 6800, think there is a 9600 version, but I use mine for outreach or just viewing so do not need greater since not a lot of slewing.
Sits on the base under the front of the scope so no cable wind up problems - small self adhesive velcro patch helps. Mine starts out at 12.5v so fine, will drop over time by about 1v then stay at that for the main duration. Have not used it greatly in the cold so temperature may throw everything out the window. That test comes soon. Something called Winter, and the East wind that arrives from Siberia every year.
Similar are made by Talentcell, the one I got was not really branded, looks the same and half the cost. Actually want another.
Posted 04 October 2019 - 07:47 PM
As far as voltage goes the celestron powerpack charges with a 15 volt charger as does my car battery jump starter but once you take it off charge they soon drop to around 13volts and continues to drop over time. I use both to run my etx as I have two locations to view from. The jump starter is also the back up for my boat battery so saves carting a pack as one is always with the boat. The internal battery is the same in both packs. Even fresh 1.5 volt AA alkaline and lithium batteries are actually just over 1.6 volts depending how long they have been sitting before use, so if you multiply that by 8 you get close to 13 volts, but because of the size they are draw down quickly with use, so slow down markedly after a short while. The larger battery packs are good for two or three sessions before slowing down. Just remember once you recharge do a calibrate motors on start up. My celestron pack is the smaller one they sell and is fine if you only want to run the scope and maybe charge your phone/ tablet. But if you want to power other stuff as well you are better off getting the larger pack.
Hope this helps
Posted 05 October 2019 - 09:36 AM
I couldn't find meades version but I did get one made by Celestron rated at 17 amps. It has a floodlight, small red flashlight, 2 usb ports, 2 car socket ports, an alarm, and an am/fm radio.
Posted 05 October 2019 - 05:32 PM
Yes that celestron powerpack will work fine mine is only the 7 amp hour and that has plenty of power for the etx, its about half the price as well. You need to give them a charge about once a month anyway to preserve the battery because they dont like to go completely flat. Not sure where you’re located but if you look up bhphotovideo.com they have both with pictures and specs.
Posted 06 October 2019 - 12:03 AM
Yes. I got my power pack from B&H. I get a lot of stuff from those guys.
Posted 06 October 2019 - 11:50 AM
FYI - The 12V adapter I bought for my LS-8 ten years ago also works on my ETX-125.
Posted 07 October 2019 - 08:11 PM
Posted 13 October 2019 - 03:33 PM
I tried charging my celestron 17 power bank when it arrived in the mail. Not a peep. Apparently I hear that the supplied charging cord is crap. Luckily I still have my harley davidson super smart battery charger. I hooked it to the terminals and it worked like a charm. Now if the clouds would just bugger off, lol.
Posted 13 October 2019 - 04:43 PM
I’m not sure about the 17 but my 7 has a rocker switch that switches power from on to off to charge you have to switch it to charge for the small charger to work it isolates operations for charging. Probably draw too much if you were trying to use it at the same time as charging. Or use the terminals as you did with a bike charger.