Best Battery for Skywatcher goto mount

[bluesilver]

Hi, Just a quick easy question i am hopping.
I am looking for a decent battery to run my Skywatcher goto mount.
It is the Skywatcher 16" Dobsonian goto mount.

I have 3 fans mounted also.
Did an Amp test today and with all fans going and the motor in the fastest setting using both up and across motions all together, I get a maximum of 1.7 amps when everything starts to move, then drop of to under 1 amp.

So i am going to say a maximum draw of 2 amps will be over the top.

Would this batter be suitable?
https://www.supercheapauto.com.au/p/century-century-ps-series-battery-ps12180/128930.html

It is a 12 Volt 18AH battery.

Any advice is appreciated.
Thanks.

[xa-coupe]

Whilst I didn't buy it for this, I use what could only be described as 'massive overkill'.



https://www.4wdsupacentre.com.au/adventure-kings-battery-98ah.html


On the face of it, the battery you list will be fine but technical specs and reality often don't meet.

[Benjamin]

Jaycar have something similar but slightly cheaper: https://www.jaycar.com.au/12v-18ah-sla-battery/p/SB2490
Guess you'd factor in the charger too:
https://www.jaycar.com.au/automatic-sla-battery-charger-6v-12v-24v-1-2a/p/MB3527

[sunslayr]

I don't know how soon you need this battery but if you want a neat and portable solution kogan sells this (https://www.kogan.com/au/buy/kogan-26800-mah-power-bank-pro-102w-pd-and-qc-30-black/) 26000 mAH usb Pd powerbank. If you combine it with a ZY12PDN (https://www.ebay.com.au/itm/100W-9V-12V-15V-20V-Type-C-USB-C-PD-2-0-3-0-to-DC-USB-QC-Trigger-Poll-Detector/312705399960?hash=item48ceb1bc98:g: 9MwAAOSwVhxef-Xy) board. Unfortunately there doesn't seem to be any in stock in Australia so you would have to wait for it to ship from China.

[mswhin63]

Based on 2A that is 9 hours of use. As long as it is only 2 Amps.

[sunslayr]

Well 9 hours of max speed slewing :lol:

[bluesilver]

Thanks for the replies, I like the Jaycar idea, nice and simple battery.

Unfortunately i have no idea at all what that ZY12PDN board is,
Looks like it just regulates the voltage to what ever voltage you want.
Reading the specs on the power bank, it is maxed out at 1.5 Amps at 12V, so right on the limit with that.
Nice idea though.

[sunslayr]

That if you are using all the ports. The ZY12PDN board lets you use the usb-pd capabilities to get 12V3A on just the usb type C port.

[bluesilver]

ah, that makes better sense,
Had a bit of a search around, can get a board out of Australia if it is the same thing.
https://www.ebay.com.au/itm/1Pc-Type-C-USB-C-PD2-0-3-0-to-DC-USB-fast-charge-trigger-Poll-detector-Charg-K7G/324158417500?hash=item4b7958ea5c:g: zLcAAOSwpcBdcfD7

[sunslayr]

That might work if the bare terminals still carry the 12v under the usb port, can't say for sure as I got the version with the screw terminals but that store is out of stock. They do have the ZYPDS but you can only use that if your mount can take 15v.

[xelasnave]

The thing to remember is astronomy batteries operate often in very cold conditions, which they don't particularly like so getting something bigger than you think you need is not a silly move...also when you have it out there keep it off the ground a wood carry box is a good idea to keep it off the ground. Also you can attach a Meter to the box that shows battery condition or volt..maybe a little red light or sectioned off for some tools and tape..whatever...and put it on charge asap after use.
Alex

[The_bluester]

I reckon a good rule is to work out what you need, add 30% fat. Then double it.

I know from experience of forgetting to turn on my DC supply one night that a 7.2AH battery in good temperature conditions will run my rig of Orion Atlas mount, cooled ZWO cam, guide cam, focuser, heater for a small refractor and small PC for about half an hour. It would be drawing at least double what the Dob would, so call that an hour or so (Probably more with the lower discharge current) so I would guess 18AH might reliably get four or five hours running a dob for visual if you don't need heaters?

That really is a back of the napkin guess, but you don't want to be over discharging an SLA battery on a regular basis or it will drop off in capacity pretty quickly.

[bluesilver]

Thanks again for the replies,
I think i might stick with the standard battery like the one from Jarcar.
The battery will just be sitting on the goto mount itself, so will go around with the mount.

[highlander2287]

I've been using the iforway battery from skywatcher with my 10" goto mount and so far it has worked quite well and is very compact just sitting on the mount.

[Hemi]

27 Amp hrs in a 600g battery pack? I don’t think that’s at 12v. The specs on Kogans website don’t give a total watt hrs number. This is the important number, when the battery can operate at a variety of voltages, it then enables you to calculate the amp hrs at your desired voltage.

Cheers

Hemi

[Sunfish]

I think you can get a cheaper 12ah battery at Jaycar. The Diamec one for $50 runs my mount and camera and heater for many hours , more than four, and I think at the cost of bigger better batteries , you could but two of these. That is 12 hour at 600 MA or 5 hr at 2 amp.

https://www.jaycar.com.au/12v-12ah-sla-battery/p/SB2489

[The_bluester]

That is interesting Ray, as I wrote above, I get maybe half an hour out of a 7.2ah, though that is running my mount PC as well (Which only runs a couple of watts typically) If I had my guess I would say it was pulling about 4A at the time which going by the data sheet should be about 60 minutes run time (Half an hour is a guess for how long it ran things, I didn't time it as my "test" was not deliberate) but it would have been somewhat derated for temperature and may not have been at 100% charge to begin with, and I can't recall how old the battery is.

In my case I only use the battery to float over any power interruptions so it does not bother me much, the new setup I am building uses two power supplies and two batteries so it should go a decent time on it's own.

[Sunfish]

Well this is a new 12ah battery , the old 7.2 was not much chop. Need to be continuously charged when not in use.

A laptop sucks up the power with all the USB connections and the screen.

I use an 18v 4-5 ah ryobi drill battery if I need to for the old Ubuntu laptop and even that does not last if not fully charged . MostLy use a cable.

My home made 12a cooler sucks the battery out in an hour so I Use the old battery off and on. The cooled camera is ok on the new battery with the heater and the mount for four hours but I think if I added a USB hub I would have to run that off the 5v connection on a drill battery as I have done before

[Merlin66]

I’ve been using a couple of 20 Ah gel cell golf buggy batteries for the past ten years.
A good triple charge battery charger and they seem to last forever.

[MountainGoat]

Perfect timing, having just picked up an Astro Fi 6 last week.


If I was to buy that battery, what other "bits" do I need to buy, to connect it to my motor. It looks like its a 5.1\2.1 I think (out and inner).


Thanks

[Sunfish]

The one I have is a standard narrow spade connector on the battery but you should ask at Jaycar as they vary in shipments and they will sell you the right connectors and try them on. The pin end, I forget but take your existing power cord in and try them .

[Sunfish]

If you can get one of those for $70 that would be great. But this probably a cheapy.

https://www.ebay.com.au/itm/Mobility-Scooter-Golf-Buggy-battery-20AH-BATTERY-AGM-12-VOLT-DEEP-CYCLE-6DZM20/133223385050?hash=item1f04bb87da:g: k9YAAOSwD6Fe5wjr

The gel ones on gumtree are $135 but that is still ok for 24ahr.

[Stonius]

Is this to insulate it from the cold for better performance?

[MountainGoat]

That's great. I have one 5k's away .... could be time for a chat.


Thanks

[xelasnave]

Yes. Batteries don't like cold and anything one can do to help is worth the effort in my view. Ask a car battery dealer when they sell the most batteries and I bet the answer will be the start of winter..the cold pushes a failing battery over the edge .I have lived for years with deep cycle batteries and solar power, no grid power, and this is one of the things I try and take care of...and dont run them down. Folk make the mistake of not realising that us use only a percentage of their rating for a start ..I try too not drop below 12 volts ..or if I think I will use 20 amps max I look for a 100 amp or higher battery..I needed 100 for the observatory but went for 120..I need 300 for the van but went 440..just rules of thumb but what you don't want is an approach that has you running a battery until it is flat ..best to leave it healthy as possible while it waits for a recharge... I have never put a hot water bottle in the battery box but the temperatures here of late has me thinking may be a good time to start...I don't have a box for what was to be my observatory battery but it sits on some thick ply which sits on some foam..it was to be housed in a covered utility box but I have not got to making that yet as my plans have had many set backs this year and new unexpected projects added..nevertheless I did my best by having that battery in the caravan annex and reasonably insulated from the ground. My 440 for the van, three batteries each have a plastic box and under a bench..gel for safety.
Alex

[Stonius]

Thanks Alex. Interesting reading. Makes me think of a time when I was in the Himalayas in a little hut which had so many holes I could see the snow outside. It was minus 15, and even my new torch batteries were flat, but if I warmed them up in my hands they would work a little longer. I guess it's all just chemical reactions, I guess.


I imagine in a box the heat the battery generates as it is used, in turn makes it more usable, by keeping temps higher.



Cheers


Markus

[Wilsil]

Last weekend we were camping in the bush and I used the gear for the first time away from home.
My car has a dual battery setup with a 105Ah AGM battery.
No problem using the HEQ5Pro GOTO with it.

[Spleenus]

I've decided to go ahead with one of these from Jaycar.

https://www.jaycar.com.au/battery-box-with-voltmeter-and-dual-usb-charger-and-dual-anderson-plugs/p/HB8504

I opted for the version with more anderson plugs so that we have the option to use it also when camping on a site with no power, but I also had very little inclination to build myself a box. This is much more neatly presented for those with limited DIY skills IMHO :)