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Power supply question - Powerwerx SPS-30DM

ap@CaptivePhotons.com
 

I have two Powerwerx SPS-30DM power supplies, the first I got with the AP1100AE and the second I got because George was persuasive that I should dedicate a power supply to the mount.  So A powers the mount, B powers a computer, router, camera, and raspberry pi weather station (about 6 amps with full on dew). 

All was great for 3 months, and in the last 10 days now twice I have had an "event" which caused all devices on "B" to reboot.  With Ray's help I determined the mount did not see a power outage (APCC's startup is different if it did).

So I checked all connections (powerpoles except where they go to end devices), double checked it was on fixed voltage, I redid the box they sit in outside with foam to keep them from sliding around, made sure wires tight, ran it indoors for days... no problem found.

Last night at 3:30 google is shouting "Wake up telescope unreachable" (google watches over things while I sleep), and sure enough, everything on "B" rebooted.  Again the mount showed no signs of a power cycle.

Additionally, I checked the UPS I have on my home computer, and it showed no utility power event.  Both the outdoor power supplies are plugged into the same extension cord, with no separate fuses or such for each, so if one went, both should go  from a utility power event. 

My main operating theory is one is bad, get it replaced.

Except: The normal operating amperage for the mount one is a tiny fraction of an amp.  I'm wondering if this could be a very brief utility power event, but the DC power at such low draw remained on for the milliseconds needed until power was restored.  (This is somewhat denied by lack of indication on my desk UPS). 

So here is my question (well, other than whether you have better ideas):  How long can a power supply like this, at 0.2a or less, provide power if the utility power goes off, and is it long enough to ride out a power glitch that would shut down another running at 6a?

I.e. is it even worth considering it is utility power as opposed to a bad power supply? 

I'd rather buy another power supply than lose a couple more nights of imaging (or get woken up to revive it), but on the other hand I hate buying a new power supply if this is really the utility screwing up the power in the wee hours as it will have the same issue. 

With 10 days (and probably 4 nights imaging, and most of the time the computer/router up during the day) this does not happen often enough to make it simple to experiment, so hoping someone can help me narrow my options.

Linwood

PS. I looked for some kind of affordable power monitor that would tell me if AC glitched, but I saw nothing reasonable; I could buy several power supplies for some of the more serious power analyzers. 

PPS. And yes, this supply would be under warranty if it really is bad, but convincing Powerwerx it is bad may be an issue; even if not, this is really about being sure I find the right culprit, not the cost of the power supply. 
Jim Crumly
 

On Fri, Dec 24, 2021 at 12:34 PM, ap@... wrote:
Linwood
A little basic electrical trouble shooting is in order.
Swap the power supplies and see if the problem follows, if not the trouble is farther up the chain like windows doing something weird in the middle of the night.
if it follows then it could be the power supply AC connection inside the box, or the output of the power supply itself. an option would be to put a UPS before the power supply.
Plug the power supplies into different plugs (swap the plugs) on the extension cord or use two different extension cords to the power supplies. could be a bad female plug on the extension cord.

hope this helps
Jim
ap@CaptivePhotons.com
 

jimwc wrote:

 

  • A little basic electrical trouble shooting is in order.
    Swap the power supplies and see if the problem follows, if not the trouble is farther up the chain like windows doing something weird in the middle of the night.
    if it follows then it could be the power supply AC connection inside the box, or the output of the power supply itself. an option would be to put a UPS before the power supply.
    Plug the power supplies into different plugs (swap the plugs) on the extension cord or use two different extension cords to the power supplies. could be a bad female plug on the extension cord.

The reason I asked about what happens in a brief utility power outage relates to trouble shooting.  I do not know what happens if utility power drops for (say) 300ms; does the (not sure of the right word here) filters of the power supply provide power to carry 0.1a through 300ms, but at 4a the DC drops to zero?  Much as the LED display stays on 10 seconds or so after you unplug it.

 

Tonight I decided (sorry George) to run everything off of one power supply.  If it is utility power that is doing this, then it will have a similar load, but this time the mount should go down also.  If it is a bad power supply (the one not in use), then it will run fine.  The advantage of this to swapping supplies (given I think a bad supply is most likely) is that I stand a better chance of being able to keep imaging.

 

Swapping power supplies would yield more likely results but … its getting closer to the new moon and is really clear and I want to do more invasive trouble shooting with clouds or with full moon at least.

 

The real problem is that if it takes 10 days to do this (and that's a single data point of an interval), this could take forever to debug.

 

I am fairly confident it is not the AC side in terms of wiring, this is fairly new stuff, 12awg extensions, good contacting plugs (and I keep them out of the grass).  Possible, but I do not think so.  I'd put that at the bottom of my guess list.

 

My GUESS is that it's something flakey in the power supply.

 

My 2nd guess is, with so much construction going on, FPL might be doing maintenance in the wee hours and causing glitches in the AC without notice, and it is the tiny load that allows the mount both times to ride through it on the waning power.  If that's possible.

 

It COULD be something intermittent in the DC side that shorts out, the PS drops DC, brings it back after a bit…. possible, but I think that would blow a fuse (there is also an external fuse, I think 10 or 15a, between the PS and the load, plus the PS's own internal protections; plus there's really not much here to short out.).

 

I do not have a suitable UPS to use, without a lot of un-doing in existing systems, and can just buy a new PS for the price of a decent heavy duty one (I might want a sine wave version to power two switching power supplies?).   I have batteries I could just power everything with, but that tells me nothing and they are HEAVY to take in and out nightly.

 

What I really wish was that I knew how to make it get worse, so it would happen more often.  Waiting a month before saying "maybe this config works" is not great.  I mean, it ran for about 3 months without a glitch, then two in 10 days.

 

Linwood

 
Jeffc
 

You would need a data logger to record the power supply input and output at a fairly high rate… and then shutdown logging after a failure/recovery.  The logger of course needs its own power supply.  I was thinking something could be cobbled together with a raspberry pi and some A/D converters.  

I also would swap supplies.  

My guess/money TBH would be windows issue.   If you have another machine , put it on the power supply also (assuming there’s capacity.).  I might have missed it in your post but … if you have other devices on AC that would be affected by a glitch, then look for evidence with those devices. 

-jeff


On Dec 24, 2021, at 3:15 PM, ap@... wrote:



jimwc wrote:

 

  • A little basic electrical trouble shooting is in order.
    Swap the power supplies and see if the problem follows, if not the trouble is farther up the chain like windows doing something weird in the middle of the night.
    if it follows then it could be the power supply AC connection inside the box, or the output of the power supply itself. an option would be to put a UPS before the power supply.
    Plug the power supplies into different plugs (swap the plugs) on the extension cord or use two different extension cords to the power supplies. could be a bad female plug on the extension cord.

The reason I asked about what happens in a brief utility power outage relates to trouble shooting.  I do not know what happens if utility power drops for (say) 300ms; does the (not sure of the right word here) filters of the power supply provide power to carry 0.1a through 300ms, but at 4a the DC drops to zero?  Much as the LED display stays on 10 seconds or so after you unplug it.

 

Tonight I decided (sorry George) to run everything off of one power supply.  If it is utility power that is doing this, then it will have a similar load, but this time the mount should go down also.  If it is a bad power supply (the one not in use), then it will run fine.  The advantage of this to swapping supplies (given I think a bad supply is most likely) is that I stand a better chance of being able to keep imaging.

 

Swapping power supplies would yield more likely results but … its getting closer to the new moon and is really clear and I want to do more invasive trouble shooting with clouds or with full moon at least.

 

The real problem is that if it takes 10 days to do this (and that's a single data point of an interval), this could take forever to debug.

 

I am fairly confident it is not the AC side in terms of wiring, this is fairly new stuff, 12awg extensions, good contacting plugs (and I keep them out of the grass).  Possible, but I do not think so.  I'd put that at the bottom of my guess list.

 

My GUESS is that it's something flakey in the power supply.

 

My 2nd guess is, with so much construction going on, FPL might be doing maintenance in the wee hours and causing glitches in the AC without notice, and it is the tiny load that allows the mount both times to ride through it on the waning power.  If that's possible.

 

It COULD be something intermittent in the DC side that shorts out, the PS drops DC, brings it back after a bit…. possible, but I think that would blow a fuse (there is also an external fuse, I think 10 or 15a, between the PS and the load, plus the PS's own internal protections; plus there's really not much here to short out.).

 

I do not have a suitable UPS to use, without a lot of un-doing in existing systems, and can just buy a new PS for the price of a decent heavy duty one (I might want a sine wave version to power two switching power supplies?).   I have batteries I could just power everything with, but that tells me nothing and they are HEAVY to take in and out nightly.

 

What I really wish was that I knew how to make it get worse, so it would happen more often.  Waiting a month before saying "maybe this config works" is not great.  I mean, it ran for about 3 months without a glitch, then two in 10 days.

 

Linwood

 
ap@CaptivePhotons.com
 

Jeffc wrote:

 

  • I was thinking something could be cobbled together with a raspberry pi and some A/D converters.  

 

I actually have some I used for a weather station, but I just doubt they are fast enough.  I'm also not sure they are good for 110v, I'd have to look.  But I just don't see it being fast enough to see AC transients, maybe I am wrong.  I do have a Pi 4 sitting around.

 

  • My guess/money TBH would be windows issue.   If you have another machine , put it on the power supply also (assuming there’s capacity.).  I might have missed it in your post but … if you have other devices on AC that would be affected by a glitch, then look for evidence with those devices. 

 

It can't be windows, as it takes down a raspberry pi and a router that are on the same DC bus.   Both have logs showing a reboot without shutdown at the same instant.  I like blaming Microsoft for things, but it just isn't possible in this case.

 

It could be something on that DC bus of course, I just can't imagine what could do it that wouldn't blow a fuse.  It's all heavy wiring (14 AWG on the common sections, 16 most others) and the power supply is good for way more power than the fusing after it.

 

What I really lack is experience… is my home UPS (for example) fast enough at detecting utility power glitches that the absence of an event in its log is strong evidence that it is not utility power?   I think it should be, but not sure.  It's a Cyber Power 1500 sine wave, so it is a moderately good home UPS.

 

My gut still tells me it's a bad power supply.  I just don't know how to prove it.  At least not until it gets more frequent.


What I will do though is put the suspect power supply inside and run the computer with it while in the house, normally I had it hooked to the mount power supply (just a more convenient cable run given the physical arrangements).  But I'll be sure to run it 24x7 inside when not imaging.  It will not have the same load (new dew heat, though I guess I could just set them somewhere on full).   And I monitor the computer with a network management system, so I'll know if it reboots while inside.

 

I've had really bad luck with power supplies.  My last attempt (prior mount) at getting a good one was a Pyramid.  Turns out it was fanless (despite the advertisement) and overheated when outside at night repeatedly.  Then I had a bad panel GFI breaker that just plain turned power off intermittently (swapped, never did it again), now this.  Murphy really does not like my setup I think.

 

Merry Christmas, thanks for helping!

 

Linwood

 
legendtrail@...
 

I get the same behavior occasionally when I've neglected to pause auto updating in windows. I don't think there's any way to shut it off, but you can prevent reboots for a 7 day period. I also second the suggestion to swap supplies.
Peter Nagy
 

Did you check Windows Update history to see if Windows downloaded and installed updates during imaging?

You can disable Windows updates by disabling the following in "Programs->Windows Administrative Tools->Services":

Windows Update
Windows Modules Installer
Update Orchestrator Service

Don't forget to re-enable Windows Update after you're done imaging to keep your computer secured.

Peter
ap@CaptivePhotons.com
 

Peter Nagy wrote:

 

  • Did you check Windows Update history to see if Windows downloaded and installed updates during imaging?

 

Sorry, I thought I was clear -- THREE separate devices went down at the same time that are all on that power supply, a windows computer, a linux computer, and a router.

 

It's not software!

 
Brian Valente
 

I have had random acts of power loss through the years.

I invested in a small simple battery backup that solved my problems. It doesn’t last for more than maybe 30 minutes, but it’s enough to avoid most brown outs and quick cuts

Brian

On Sat, Dec 25, 2021 at 7:05 AM ap@... <ap@...> wrote:

Peter Nagy wrote:

 

  • Did you check Windows Update history to see if Windows downloaded and installed updates during imaging?

 

Sorry, I thought I was clear -- THREE separate devices went down at the same time that are all on that power supply, a windows computer, a linux computer, and a router.

 

It's not software!

 

--
Brian 



Brian Valente
Peter Nagy
 

Maybe invest in PWRGate like this:

https://powerwerx.com/west-mountain-radio-pg40s-super-pwrgate

Super PWRgate PG40S is a 12 volt backup power system that can supply up to 40 amperes continuously from either a Power Supply or a Battery, and can also charge the battery with its high performance charger.

Peter
ap@CaptivePhotons.com
 

Peter Nagy wrote:

 

 

I had not seen that before, but it would require (if I'm not misreading it) that I haul a battery out to the telescope each night in addition to the power supply.  I guess I could buy a couple of small, lighter ones, but the ones I have for dark site are almost 50# each.  Plus two of these.  That's a lot more.

 

But it is an interesting setup, I think I would love it if I had a permanent setup, a more efficient form of a UPS since it is on the DC side.

 

I wonder if someone has these with a built in small lifepo4 battery, just something with a few amp-hours to ride through small outages but only weighs a few pounds.  That might be worthwhile for a daily setup (though probably 2-3x the price so maybe not).

 

If I go the UPS route, I think just a 1200-1500w sine wave home UPS sitting on the outdoor porch, and plug the extension into that, would be the way I go. I just don't know if I'm fixing an actual problem though, given the lack of my indoor UPS indicating any power events either time.

 

It ran all last night on the mount power supply for both.  Which I admit did not tell me a lot.  Proving a negative is hard.  I guess I really do need to swap power supplies instead, I'll do that if I can get out tonight.  The suspect one is running the computer now, I'll go hang some dew strips on it also to get the power back up to normal, but given the long interval between failures am not hopeful.

 

I want to take the suspect one apart, make sure it's not something like a bug that crawled inside and committed suicide, but since it is under warranty I'm hesitant to break the seal (interesting since their adjustment for calibration is inside, that they seal it, I guess they think you should not adjust anything).

 

Linwood

 
Peter Nagy
 

I don't think PWRgate is useful for dark site unless the dark site has 110VAC outlets. If a brownout occurs, the PWRgate will automatically and very quickly switch to battery power and then back to power supply when brownout recovers.

Also the PWRgate charges the battery (power supply must also be running) during imaging so that the battery will always be charged when power outage or brownout occurs.

You don't need a large or heavy battery for this setup. The battery is for backup until power from utility company restores. The battery should be small enough to last 30 minutes until power is restored. 

Peter
Peter Nagy
 

BTW, I've been using single power supply/battery along with PWRgate for years to power everything without issues. My area is very dry so no dew heater. My laptop is always powered with 110VAC and battery backed with included laptop battery. 

Peter
Roland Christen
 

One thing to keep in mind: Linear power supplies usually have large capacitors on their output line (because they have to filter 60hz ripple). These can hold power for up to a second or more depending on load current and the size of the capacitor. Switching power supplies are much more efficient, however they generally do not have large capacitors on the output line, and therefore will drop to zero in milliseconds.

Finally, you can buy a large electrolytic and wire it across the DC output line. The bigger the better for holding up the power during a power glitch or power surge.

Rolando

-----Original Message-----
From: ap@... <ap@...>
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Sent: Fri, Dec 24, 2021 5:14 pm
Subject: Re: [ap-gto] Power supply question - Powerwerx SPS-30DM

jimwc wrote:
 
  • A little basic electrical trouble shooting is in order.
    Swap the power supplies and see if the problem follows, if not the trouble is farther up the chain like windows doing something weird in the middle of the night.
    if it follows then it could be the power supply AC connection inside the box, or the output of the power supply itself. an option would be to put a UPS before the power supply.
    Plug the power supplies into different plugs (swap the plugs) on the extension cord or use two different extension cords to the power supplies. could be a bad female plug on the extension cord.

The reason I asked about what happens in a brief utility power outage relates to trouble shooting.  I do not know what happens if utility power drops for (say) 300ms; does the (not sure of the right word here) filters of the power supply provide power to carry 0.1a through 300ms, but at 4a the DC drops to zero?  Much as the LED display stays on 10 seconds or so after you unplug it.
 
Tonight I decided (sorry George) to run everything off of one power supply.  If it is utility power that is doing this, then it will have a similar load, but this time the mount should go down also.  If it is a bad power supply (the one not in use), then it will run fine.  The advantage of this to swapping supplies (given I think a bad supply is most likely) is that I stand a better chance of being able to keep imaging.
 
Swapping power supplies would yield more likely results but … its getting closer to the new moon and is really clear and I want to do more invasive trouble shooting with clouds or with full moon at least.
 
The real problem is that if it takes 10 days to do this (and that's a single data point of an interval), this could take forever to debug.
 
I am fairly confident it is not the AC side in terms of wiring, this is fairly new stuff, 12awg extensions, good contacting plugs (and I keep them out of the grass).  Possible, but I do not think so.  I'd put that at the bottom of my guess list.
 
My GUESS is that it's something flakey in the power supply.
 
My 2nd guess is, with so much construction going on, FPL might be doing maintenance in the wee hours and causing glitches in the AC without notice, and it is the tiny load that allows the mount both times to ride through it on the waning power.  If that's possible.
 
It COULD be something intermittent in the DC side that shorts out, the PS drops DC, brings it back after a bit…. possible, but I think that would blow a fuse (there is also an external fuse, I think 10 or 15a, between the PS and the load, plus the PS's own internal protections; plus there's really not much here to short out.).
 
I do not have a suitable UPS to use, without a lot of un-doing in existing systems, and can just buy a new PS for the price of a decent heavy duty one (I might want a sine wave version to power two switching power supplies?).   I have batteries I could just power everything with, but that tells me nothing and they are HEAVY to take in and out nightly.
 
What I really wish was that I knew how to make it get worse, so it would happen more often.  Waiting a month before saying "maybe this config works" is not great.  I mean, it ran for about 3 months without a glitch, then two in 10 days.
 
Linwood
 

--
Roland Christen
Astro-Physics
Jeffc
 

On Dec 25, 2021, at 8:42 AM, Peter Nagy <topboxman@...> wrote:

I don't think PWRgate is useful for dark site unless the dark site has 110VAC outlets.
True.

I now use a GoalZero Yeti 1500x at dark sky sites, and also at home. It’s about the size and weight of a car battery (I move it on a furniture dolly). This replaces 4 deep cycle batteries I previously used over the years. The 1500x has a built in sine wave inverter, and 12v power pole output.
The 1500x can also behave like a UPS in that it supports charging while in use. There’s other models of so-called “solar generators” which are lighter/smaller and use other battery chemistry.
Tho..definitely not as convenient as a couple small switching power supplies for AC supply home use.

-jeff
Eric Weiner
 

Jeff,

Out of curiosity, do you find the 1500x to be a bit overkill at dark sky sites for a night of imaging, or are you exhausting it down quite a bit?  I do well with a pair of AGM 12V batteries in parallel, but I was curious how well the Yeti does considering Lithium batteries don't do well in cold weather.

Thanks,
Eric
Michael Kelly
 

While often my dark sky imaging involves camping, so this is definately overkill, but I parallel 2-100Ah LifePo batteries and a 2000w inverter that I leave in the truck. Then run an extension cord to a Powerwerx 30A power supply, so its basically just like being home where everything is happy operating at 14vdc. While this 'up then down' conversion is certainly not the most efficient, I have run 3 rigs, a laptop and kept iPads charged all night with room to run the coffee maker in the morning before recharging with solar and a small Honda generator. 

The batteries are maybe 25lbs/each and the inverter is maybe 10lbs. 

Best,

Michael

On Monday, December 27, 2021, 12:24:14 PM EST, Eric Weiner <weinere@...> wrote:


Jeff,

Out of curiosity, do you find the 1500x to be a bit overkill at dark sky sites for a night of imaging, or are you exhausting it down quite a bit?  I do well with a pair of AGM 12V batteries in parallel, but I was curious how well the Yeti does considering Lithium batteries don't do well in cold weather.

Thanks,
Eric

Brian Valente
 

Wow what does a battery setup like that cost?

On Mon, Dec 27, 2021 at 9:45 AM Michael Kelly <Michael@...> wrote:
While often my dark sky imaging involves camping, so this is definately overkill, but I parallel 2-100Ah LifePo batteries and a 2000w inverter that I leave in the truck. Then run an extension cord to a Powerwerx 30A power supply, so its basically just like being home where everything is happy operating at 14vdc. While this 'up then down' conversion is certainly not the most efficient, I have run 3 rigs, a laptop and kept iPads charged all night with room to run the coffee maker in the morning before recharging with solar and a small Honda generator. 

The batteries are maybe 25lbs/each and the inverter is maybe 10lbs. 

Best,

Michael

On Monday, December 27, 2021, 12:24:14 PM EST, Eric Weiner <weinere@...> wrote:


Jeff,

Out of curiosity, do you find the 1500x to be a bit overkill at dark sky sites for a night of imaging, or are you exhausting it down quite a bit?  I do well with a pair of AGM 12V batteries in parallel, but I was curious how well the Yeti does considering Lithium batteries don't do well in cold weather.

Thanks,
Eric

--
Brian 



Brian Valente
Michael Kelly
 

About $2k for the batteries, inverter and 200w solar charger. You can use one 100Ah battery and a smaller inverter as that would handily operate 2 rigs. I'm sure someone will say just run it off the battery, but my thoughts on this is that the battery is 12.8v, by the time that sees each device its low 12's. The 'benefit of the up/down efficiency loss' is that you don't need the batteries close to your rigs. Batteries stay in the truck and use a 100' 12Ga extension and then locally convert to 14vdc. Even if you're spread out, just run another extension cord to a local power supply so you aren't running long 12v power cords.  

On Monday, December 27, 2021, 12:49:10 PM EST, Brian Valente <bvalente@...> wrote:


Wow what does a battery setup like that cost?

On Mon, Dec 27, 2021 at 9:45 AM Michael Kelly <Michael@...> wrote:
While often my dark sky imaging involves camping, so this is definately overkill, but I parallel 2-100Ah LifePo batteries and a 2000w inverter that I leave in the truck. Then run an extension cord to a Powerwerx 30A power supply, so its basically just like being home where everything is happy operating at 14vdc. While this 'up then down' conversion is certainly not the most efficient, I have run 3 rigs, a laptop and kept iPads charged all night with room to run the coffee maker in the morning before recharging with solar and a small Honda generator. 

The batteries are maybe 25lbs/each and the inverter is maybe 10lbs. 

Best,

Michael

On Monday, December 27, 2021, 12:24:14 PM EST, Eric Weiner <weinere@...> wrote:


Jeff,

Out of curiosity, do you find the 1500x to be a bit overkill at dark sky sites for a night of imaging, or are you exhausting it down quite a bit?  I do well with a pair of AGM 12V batteries in parallel, but I was curious how well the Yeti does considering Lithium batteries don't do well in cold weather.

Thanks,
Eric

--
Brian 



Brian Valente
Jeffc
 

Eric…. Here’s a few reasons I went for the Yeti1500x…

First tho, I want to mention:  At the time of the 1500x purchase I was considering building a LiFePO4 based supply but there were some logistical and component supply issues going that route; the 1500x was a choice in balancing weight with capacity, and also availability (REI stocks the GoalZero gear.)

1) Space.   While I have a collection of optima yellow tops (AGM), these take up space in the vehicle and are heavy to load/unload/move.  With recent vehicle changes here , using the yellow tops became a showstopper.   

2) Capacity - Sometimes i go out for multiple nights and would prefer to over-provision.  One time I was out and underestimated the power consumption and was hurting for power. (I think the weather was colder than normal, and I switched to a new camera drawing more power.)   It turns I could only reliably get 1 night out of the YellowTops.  And on top of that I would need to charge them during the day.. which meant bringing multiple AGM chargers for multi-night trips (when there’s a generator or nearby daytime charging.)

3) Regulated 12v.   The Optimas worked great but were not regulated.   I fried two 12v “auto” laptop adapters (replaced under warranty) as a result of the voltage dropping below something 11.5 volts. 

4) I’m in the SFBayArea .. so it’s not super cold here, but I’ve had the 1500x out in near freezing weather (for a couple hours) at remote sites and did not notice any issues.  I have the 1500x in a soft case which has some insulation, so that might help with the cold.  I doubt I’ll be using the 1500x at -4F (or even below 32F much), but if I did I would just put it in a cooler.
(Fwiw, I have noticed cold weather issues with the YellowTops.)

5) Turnkey… at the time I wasn’t in the position to build a DIY power setup (too many projects) and was looking for a turnkey solution with quick charge capability (the 1500x charges in about 3 hours with the 600w charger.)

5) Regarding capacity - I use an 85w computer (desktop class, not laptop), camera and a couple dew heaters in addition to the mount.  The camera probably averages about 3amps with peaks at 5amps.  With the YellowTops I would designate one battery for running the dew heaters, and also separate the camera, mount, and computer on their own batteries.  I would monitor the battery voltage through the night — a bit annoying.   All this hassle is gone with the 1500x.   And with multiple flavors of ports I can also use the 1500x for daytime charging a laptop and cellphone. 
One night uses about 40-50% of the 1500x capacity.  If I’m conservative I figure I can get two nights out off the 1500x, but usually I just charge it during the day with the 600w charger. 
The 1500x also does double duty as a power supply for the occasional Bay Area power failures. 

 -jeff

On Monday, December 27, 2021, 12:24:14 PM EST, Eric Weiner <weinere@...> wrote:


Jeff,

Out of curiosity, do you find the 1500x to be a bit overkill at dark sky sites for a night of imaging, or are you exhausting it down quite a bit?  I do well with a pair of AGM 12V batteries in parallel, but I was curious how well the Yeti does considering Lithium batteries don't do well in cold weather.

Thanks,
Eric
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