Synscan GoTo PowerBank?

[Wolfen54]

Afternoon,

I have managed to get my hands on a Synscan WiFi GoTo mount and notice it can be powered by AAs (8x) or dc connection.

The manual states it requires 12v D.C. running at 1 amp.

i am aware that there powerbanks made by skywatcher and Celestron for this but wondered if one of my several 20,000 mah USB powerbank would work? ( they all appear to be 5v but have different amps, 2.1, 3, 5!!)

I have seen multiple cables on amazon but concerned that either it’s not enough amps (0.88 is often quoted) or that the cable will allow more then 1 amp which from my basic knowledge would fry the power board?

I am happy to charge it for when it’s needed and would probably be using it for an hour or two max and not needing to power anything else

Advice please!

 

thx

 

[michael.h.f.wilkinson]

I tend to go for sealed lead acid batteries, of the deep-cycle variety. I have a 20 Ah and a 105 Ah variety (the latter was on offer for a  ridiculously low price). I then make my own cables, usually 1.0 mm^2, which is plenty for most mounts. This should work better than having to up 5V to 12V

[DaveL59]

if the only output on your powerbank is USB then it'll only deliver 5v. Some also have a second output for laptops which may be 19v or if lucky 12v but do check the actual voltage with a meter before hooking to your SynScan.

I use a Car jump-starter LiPo 20Ah pack and that gives 15+v on the car outlet, so I use a buck converter to provide a 12v regulated output into the SynScan and it works nicely. Does mean a bit of DIY sorting suitable connectors and cables but its compact and lightweight where lead batteries are heavy and need to be maintenance charged to prevent early demise of the battery.

[Wolfen54]

Thank you.

 

would delivering 1.5 amps be bad for the circuit though?

 

surely a lot of these lead batteries output more then 1 amp?

[DaveL59]

the circuit and motors will draw what they require, so long as the power source and cables are able to deliver it.  The voltage applied tho, if it exceeds the max could cause issues hence I suggest to test the voltage before hooking up and why I've put a buck converter in to limit it to 12v after finding the pack I have can deliver a bit over 15v.

Best not to try stepping up from 5v to 12v tho as that may not keep up with load demand during a slew and you'd get errors. You'd need some significant capacitors on the 12v side of that sort of setup to soak up peak demands especially on a long skew which would be drawing peak current.

[Wolfen54]

Thank you. I think I have a solution, I take it that this:

https://www.halfords.com/motoring/battery-maintenance/jump-starters/4-in-1-jump-starter-594335.html
and this (swapping out the fuse for like a 1.5 amp) would this work?

https://www.amazon.co.uk/dp/B01N078O5B/ref=cm_sw_r_cp_api_i_pn9vFb7R0M0G0

 

thank you

[DaveL59]

that'll be a lead battery unit, likely only 7Ah or maybe 12Ah so you would need to be sure and charge it after a session and then maintenance charge it every month or so to prevent a dead battery. Upside the battery can be replaced reasonably cheap, downside weight and you really only get 50-60% of the rated Ah capacity, less if its cold before the terminal voltage would drop far enough for the mount to struggle.

Other than that, yeah it probably would work ok 🙂

[Mcwaffles2003]

Snagged a couple of these recently. Going to wire them in parallel to run my setup.

[Geoff Lister]

Welcome to SGL.

My Skymax mount needs close-to 12V for reliable operation. I have various other mounts, and measured the current taken during start-up (before starting alignment - motors off), slewing, and object tracking.

I would expect the Synscan WiFi mount to have similar current consumption to the Celestron Cosmos, above.

These are some of my power sources:-

Most of the time, when observing from my back garden, I use the 12V 2A plug-top supply; with the supply body plugged into a mains extension lead, in an old shoe box to protect the live bits from dew formation. I extended the 12V output lead, with some white, heavy-duty, bell-flex. This shows up better in the dark, so I am less likely to trip over it.

For portable use, I tend to use the pair of 6V 2600mAh battery packs, "borrowed" from my radio-controlled model sailing yachts. These are fine for an evening's observing. They are equivalent to the 10-cell holder, but give a more-reliable electrical contact between cells.

I have also used my 4-in-1 jump starter pack. These have, in theory, a 17Ah (17,000 mAh) capacity, but should not be discharged below 50% (except in an emergency), and then recharged immediately after use. One of these should give over 24 hours of mixed slewing and tracking.

Geoff

[Wolfen54]

Hello @Geoff Lister,

Thank you for that. Questions if you don’t mind:

1) Why would you use the 6v x2 if you can have rechargeable batteries in either the mount or your 10x pack?

 

1b) Do you have a wiring diagram for that Y connection?

2) What’s the 3S at the top and how do you gurantee the 12v from it?

3) Have you considered a Usb powerbank with a voltage reg applied to it? 
 

Thank you

Edited September 9, 2020 by Wolfen54

[Geoff Lister]

1 hour ago, Wolfen54 said:

1) Why would you use the 6v x2 if you can have rechargeable batteries in either the mount or your 10x pack?

The rechargeable batteries have a nominal terminal voltage of 1.2V, whereas the alkaline batteries are 1.5V. Where the mount, or supplied pack, takes 8 cells, using rechargeables gives you 9.6V instead of 12V. The Synscan handset/mount interface needs a minimum of about 11V for reliable operation. The 6V packs give about 7.2v when freshly charged, and stay above 6v until they are close to being discharged.

1 hour ago, Wolfen54 said:

 1b) Do you have a wiring diagram for that Y connection?

Sorry, No. The packs are wired in series. The photo shows a short loop, where the red wire from one connector is connected to the black wire of the other. The other wires are connected to the power jack (5.5mm dia. outer sleeve negative - to black wire, and internal 2.1mm dia. sleeve positive to red wire). The "spare" third connector is used to charge the combined batteries.

1 hour ago, Wolfen54 said:

2) What’s the 3S at the top and how do you gurantee the 12v from it?

The 3S LiPO pack gives 12.6V when freshly charged. I only use it as a backup. The cells should not be discharged to below 3V, but the mount alignment and tracking will drop out well before this point. The pack has a special 4-way connector, for use with a balancing charger, and I have a special plug-in voltmeter module that cycles through the cells and gives a "beep" if they are getting low (it also has 7-segment displays but these need to be masked to protect night-vision).

1 hour ago, Wolfen54 said:

3) Have you considered a Usb powerbank with a voltage reg applied to it?

Yes, it is possible to use a boost regulator to convert the +5V to +12V, but these packs already incorporate a regulator, to get a constant +5V from the internal battery as it discharges. The mAh values quoted for these packs tend to be for the cells at a nominal 3.7V, so give about half that at 5V and about a quarter at 12V.

 

I hope that this answers your questions.

Geoff

[cletrac1922]

23 hours ago, Wolfen54 said:

Afternoon,

I have managed to get my hands on a Synscan WiFi GoTo mount and notice it can be powered by AAs (8x) or dc connection.

The manual states it requires 12v D.C. running at 1 amp.

i am aware that there powerbanks made by skywatcher and Celestron for this but wondered if one of my several 20,000 mah USB powerbank would work? ( they all appear to be 5v but have different amps, 2.1, 3, 5!!)

I have seen multiple cables on amazon but concerned that either it’s not enough amps (0.88 is often quoted) or that the cable will allow more then 1 amp which from my basic knowledge would fry the power board?

I am happy to charge it for when it’s needed and would probably be using it for an hour or two max and not needing to power anything else

Advice please!

 

thx

 

 

I use a car jump start pack to power my EQ5pro mount

Can power the mount for over a week when attending Astrofests down under

Pic of my ED80 on EQ5pro, showing jump start pack

John

 

 

[johninderby]

I have had absolutely zero problems using the Duracell Precharge AA 2500mah batteries in my AZ-GTi mount. Hold a charge for. 12 months.

The specs for the AZ-GTi mount say 8 to 14 volts required. The precharge batteries do hold their output better than regular rechargeables though which probably explains why they work well for this mount. Of course no handset used so using a handset could give problems.

I do have a Tracer LiFeP04 battery that can be used but not  needed it yet.

Edited September 9, 2020 by johninderby

[ScouseSpaceCadet]

I was using a 20000mah USB power bank with a 5v-12v converter cable. However I wondered if the occasional issues with the AZGTI were a result of this. I've changed to a Talentcell 6000mah@12v battery. A search will find it's commonly used with the likes of AZGTIs and Star Discovery Synscan style mounts.

Whether or not it's any better I don't know due to weather, however I have a sneaky suspicion it will be...

 

https://www.amazon.co.uk/TalentCell-Rechargeable-6000mAh-12000mAh-Lithium/dp/B0713T4XT9/ref=mp_s_a_1_1?dchild=1&keywords=talentcell+6000&qid=1599659369&sr=8-1

Bear in mind the cable is way too short. A new one ranges from around £1.87 for a generic el cheapo to £17 for a snazzy Lynx Astro job.

Edited September 9, 2020 by ScouseSpaceCadet

[Geoff Lister]

17 hours ago, johninderby said:

The specs for the AZ-GTi mount say 8 to 14 volts required

I'm glad to see that Skywatcher's more recent designs will work with a lower supply voltage. My Skymax and Skyliner mounts each have a V3 Synscan handset, which has a specified working range of 11 to 15V. The manual for my (again more recent) Virtuoso mounts, gives a range of 7.5 to 14V for an external supply; but I do not know if the bottom end of the voltage range applies when I use the mount with one of my V3 Synscan handsets.

The manual for my Celestron Cosmos WiFi mount gives power requirements of (a) 8-off AA batteries, (b) 12V DC source with at least 1A capacity {no voltage range specified}, or (c) a Celestron PowerTank.

Geoff

[johninderby]

I like the Duracel Pecharge batteries as they are 2500 mah and deliver 1.2v until  they are nearly discarged. and will keep a full charge for a year. Downside is they aren’t cheap..

Edited September 10, 2020 by johninderby

[Wolfen54]

Thank you guys.

The 12v minimum is the real sticking point so may have to go with something like the Talentcell.

Some portable car chargers also look intresting

 

Edited September 10, 2020 by Wolfen54

[johninderby]

I’m not sure how long the precharge batteries will last as I’ve not used it long enugh to find out. Would imagine would be good for an evenings or two use per charge.

[Physopto]

On 08/09/2020 at 19:55, Wolfen54 said:

Thank you. I think I have a solution, I take it that this:

https://www.halfords.com/motoring/battery-maintenance/jump-starters/4-in-1-jump-starter-594335.html
and this (swapping out the fuse for like a 1.5 amp) would this work?

https://www.amazon.co.uk/dp/B01N078O5B/ref=cm_sw_r_cp_api_i_pn9vFb7R0M0G0

 

thank you

Just come across this line of inquiry.

I would agree with those that list LiPo type batteries as being much better than Lead Acid. They are longer lasting and much safer if handled correctly. Of the LiPo types LiFePo4 are the safer type. These are slightly heavier but much safer again. Initial cost is always important but if you can afford them over time much cheaper. You will get 95% of the rated charge out of them as opposed to about 50% of the Lead Acid type. LiFePo4 types also don't mind being discharged below 50% whereas Lead Acid are notorious for being damaged  by this deep discharge. I have recently come across a company selling 20Ah LiFePo4 batteries for about £120. Sounds a lot of money, but in comparison to the Halford's starter type you listed above much cheaper and a lot longer lasting.

https://www.ksenergy.co.uk/store/product/model-ks-20-12v-20ah-lifepo4-lithium-leisure-battery

I have just purchased a 120Ah caravan battery from them. It has not arrived as yet, but hopefully no problems with it. You can expect over 2000/5000 recharge cycles for this type of battery compared to Lead Acid's 200 approx recharges. You would also need a Lead Acid of about 35Ah to get the same power output as that of a 20Ah LiFePo4 battery.

Lead Acid batteries have a very curved discharge graph of their output characteristics. So you can expect a quick drop from their full voltage of 126/8 volts to that of half charge at about 12.4 volts Whereas LiFePo4 batteries maintain over 12 volts until about 80% discharge. ( It does vary slightly, but not by much)

This is very important if you are worried about the voltage at the mount.

Derek

PS.

It is very important never to try to recharge a LiFePo4 or LiPo battery  at or below ZERO Degrees C. It will severely damage the battery. But these batteries can be used between -20 deg C and 40 deg C without any problems.

Edited September 10, 2020 by Physopto

[kevenh]

On 09/09/2020 at 14:49, ScouseSpaceCadet said:

 I've changed to a Talentcell 6000mah@12v battery. A search will find it's commonly used with the likes of AZGTIs and Star Discovery Synscan style mounts.

<snip>

Bear in mind the cable is way too short. A new one ranges from around £1.87 for a generic el cheapo to £17 for a snazzy Lynx Astro job.

Hi.  How well is the Talentcell working out for you?

Did you get new cables?

Amazon have a bigger Talentcell, a 72W one

With how you got on with the 36W would you change anything?

Thanks in advance. 

I hate burning through alkaline batteries & think standard AA nimh will be too low in the volts area

[ScouseSpaceCadet]

1 hour ago, kevenh said:

Hi.  How well is the Talentcell working out for you?

Did you get new cables?

Amazon have a bigger Talentcell, a 72W one

With how you got on with the 36W would you change anything?

Thanks in advance. 

I hate burning through alkaline batteries & think standard AA nimh will be too low in the volts area

The Talentcell battery works great. It's still on four out of five green lights, after approx 10-12 hours use. 

I'm using the £1.87 Amazon cable with no issues. 

Edited September 28, 2020 by ScouseSpaceCadet

[kevenh]

Huge thanks for the prompt feedback 👍🏻
I’ll also go for the more compact sized 36W version.

[BS269]

On 28/09/2020 at 18:33, ScouseSpaceCadet said:

The Talentcell battery works great. It's still on four out of five green lights, after approx 10-12 hours use. 

I'm using the £1.87 Amazon cable with no issues. 

Sorry to jump on the thread.. I’m interested in the talentcell batteries but read a warning on Amazon to not use in humid or wet places. Given how bad we get dew in the UK have you ever had problems or worried about it getting wet??

[ScouseSpaceCadet]

On 19/11/2020 at 23:58, BS269 said:

Sorry to jump on the thread.. I’m interested in the talentcell batteries but read a warning on Amazon to not use in humid or wet places. Given how bad we get dew in the UK have you ever had problems or worried about it getting wet??

The Talentcell batteries are commonly used to supply small mounts and I've not read or heard of one failing due to dew. Mine is secured to the tripod in a very old compact camera bag with a top flap covering the power supply.

Shielding the battery from the elements will obviously prolong its life and it will discharge slower than if exposed and cold.

There's lots of different options for bags. An example being, an army surplus magazine pouch or similar. Velcro tensioning straps or bungies can be picked up cheaply.

Edited November 24, 2020 by ScouseSpaceCadet