Trying to solve a power 'delay' issue...

[CaptainPalapa - DWO]

We are full-time RV'ers. We're doing more and more boondocking and all is good with our 4x100ah LiON batteries, solar and generator.

What we do have is a small issue I'd like to see if anyone has any solutions / ideas to resolve. We work full time, and we carry a variety of electronics. I have the majority of things wired to DC power, like our network switch, cell provider router (Pepwave) and various other things. We have two appliances, however, that require AC power. One of these is a Drobo NAS (Network Attached Storage) and our new Starlink.

The Drobo has a great feature in that it contains its own small battery and when power loss is detected, it shuts down. This is great. However, while we're boondocking, we are switching from our inverter to our generator and back to the inverter usually more than once per day. There is a slight delay when switching between these power sources. Our solar company explained that the delay is in there and should not be removed because of switching from (I think he said) 2-phase and 3-phase power. (I might not have the right, but the delay is real.) This means that the Drobo and the Starlink both shut down, then take time to come back up. The Drobo is particularly slow, as its an older unit. The Starlink would probably only draw about 50W/120v and the Drobo likely about the same (not during spin up, which I'm trying to avoid.)

I've considered using a UPS just to remove the delay. And at the end of the day, when we switch off all AC power and head to bed, I know I would have to turn off any UPS devices. (I don't need them to power the devices, just keep them up for a few seconds while the power switches.) I've tried all manner of searching to find a tiny UPS that might cover this kind of scenario. As for true UPS devices, the best I can find is an overly-large (for this purpose) APC unit. (https://www.amazon.com/dp/B073Q3BSPG/) It's really overkill and with an RV, every pound of added weight matters. The other that might work is this one: https://www.amazon.com/65Watts-Portable-Charger-Battery-Notebooks/dp/B07P87JTVT/

And right now, I need TWO of these, as these two devices are on opposite ends of our 44' fifth wheel. I don't mind an alarm indicating power loss, as long as the alarm stops when power is restored. In fact, the alarm might be good to let me know "hey, you shut off power for the night, but you forgot to turn me off!".

Any suggestions, thoughts? Product suggestions would be fine.

 

[TorC]

I'd be very surprised if it's a 2-phase to 3-phase switch. 2-phase exists, but is very rare. 3-phase is common, but not at the level of power you're dealing with.

My first thought for a proper solution would be toward a different inverter. Don't know as either quite fits what you want, but both my Samlex Evo 2224 and Outback Radian are designed so they can come up and transfer from grid to inverter with UPS-grade half-cycle (16.7ms, IIRC) timing. On grid restoration, they'll maintain inverting until they can synchronize to the incoming power and transfer back at AC zero crossing for no perceptible power blip to devices.

Other inverters to do the same should be easy to find. Just look for the specification of transfer time back to inverting on incoming AC power loss.

ETA: here is the specification for one of my inverters: https://www.donrowe.com/v/vspfiles/pdf/evo_series_spec_sheet.pdf See page two, the Transfer Relay section for what a good inverter can and will do.

 

[DIYrich]

https://www.amazon.com/APC-Battery-Protector-Back-UPS-BE425M/dp/B01HDC236Q

 

[CaptainPalapa - DWO]

I'd be very surprised if it's a 2-phase to 3-phase switch. 2-phase exists, but is very rare. 3-phase is common, but not at the level of power you're dealing with.

My first thought for a proper solution would be toward a different inverter. Don't know as either quite fits what you want, but both my Samlex Evo 2224 and Outback Radian are designed so they can come up and transfer from grid to inverter with UPS-grade half-cycle (16.7ms, IIRC) timing. On grid restoration, they'll maintain inverting until they can synchronize to the incoming power and transfer back at AC zero crossing for no perceptible power blip to devices.

Other inverters to do the same should be easy to find. Just look for the specification of transfer time back to inverting on incoming AC power loss.

ETA: here is the specification for one of my inverters: https://www.donrowe.com/v/vspfiles/pdf/evo_series_spec_sheet.pdf See page two, the Transfer Relay section for what a good inverter can and will do.

Thanks, I'll look into this, though that would require a major rewire and investment I'm hoping to avoid. This problem isn't a show-stopper, but it's annoying. Kinda looking for a low-budget solution.

 

[CaptainPalapa - DWO]

https://www.amazon.com/APC-Battery-Protector-Back-UPS-BE425M/dp/B01HDC236Q

That's just a fairly standard UPS, and having had a similar one in the past, they're quite heavy, and overkill for a 2 to 3 second power delay. Thanks for posting it, though.

 

[SparkyJJO]

That's just a fairly standard UPS, and having had a similar one in the past, they're quite heavy, and overkill for a 2 to 3 second power delay. Thanks for posting it, though.

Define "heavy"? It is a few pounds, yes, but is a handful of pounds really a problem?

 

[CaptainPalapa - DWO]

Define "heavy"? It is a few pounds, yes, but is a handful of pounds really a problem?

Yes and no. For starters, "heavy" also implies overkill. I just don't need that much battery power available for a very, very short window. Secondly, in an RV, every pound absolutely matters. Things tend to come "into" the RV more than they go "out". I'm already carrying 1500 pounds of motorcycles, and when you add in hundreds of pounds of water, waste, fuel, food, etc... yes, "watching your weight" really, really matters. If I were at the old sticks-n-bricks (house), I wouldn't think twice about one of those. (In fact, I did have one of those!)

 

[TorC]

The problem for any small UPS is that the batteries aren't so happy with very high current demands, and with inverter passive losses, there's a limit to how small they can make them, especially when they know people will plug oversize things into them for the size of the UPS.

@CamperJack - MyRVRadio Regarding the inverter, there's a good chance something exists that's pretty much a drop-in replacement in size, shape, and voltage for your existing inverter. I merely linked to a spec sheet I know off the top of my head can do what you need. Samlex also makes good 12V inverters. Pricier than some, but their better ones are highly reliable, and produce clean power that won't disrupt nearby radios. Plenty of others make perfectly serviceable inverters. Just look at their transfer time specs.

 

[DarrylG]

I think I would figure out a way to have the two items on the same circuit and add one simple UPS, like the one DIYrich mentioned. If you wanted to save the weight, you could possibly use a battery source you already have as these items typically work on a small 12v SLA battery. They might work fine off of your LION batteries depending on the voltage. Or your standard "house" battery.

 

[CaptainPalapa - DWO]

I think I would figure out a way to have the two items on the same circuit and add one simple UPS, like the one DIYrich mentioned. If you wanted to save the weight, you could possibly use a battery source you already have as these items typically work on a small 12v SLA battery. They might work fine off of your LION batteries depending on the voltage. Or your standard "house" battery.

It's possible, maybe, to run the Drobo on the 12V setup like I do for a lot of the other electronics. The difference is, those all stay on all the time, whereas I definitely don't want the Drobo on all the time. (Much more power hungry.) Getting the Starlink to 12V, that's a messy proposition, unfortunately. It can be done, but requires cutting the proprietary cable, flipping a pair of the Cat6 cable, replacing all the RJ-45 connectors and adding a setup (12v to 24v? 48v?) into the circuit. Not prepared for the latter, and I'd have to install a new switch for the Drobo if I powered it via 12v directly. But these are good thoughts, and the kind of input I'm seeking, for sure. I might end up doing the 12v and switch on the Drobo, as I can put the switch where I can reach it. (All this is up in a cabinet that requires getting out a ladder to get to!)

Since I do want the Drobo off when power is off (off for good, not just switch delay), maybe I can find a 120v gizmo that could send a power on/off signal to 12v. Might have to build such a thing. Heh.

 

[TorC]

For that kind of signaling, it would probably work just fine to have a little USB power adapter on both the inverter input and output. Might want to put a diode in each line. Feed the combined output to a 5V (maybe 3V) coil NO relay. When there is AC power on either inverter input or output the relay will be held closed. When both cut out, it'll open and kill power to the Drobo.

On the SL, is that something different than bog standard PoE? I'd expect PoE from 12V adapters already exist, though I haven't needed one to search it out.

 

[CaptainPalapa - DWO]

On the SL, is that something different than bog standard PoE? I'd expect PoE from 12V adapters already exist, though I haven't needed one to search it out.

Here's an article on making Starlink DC that I've referenced a few times to others: https://www.offgridcto.com/2022/05/23/starlink-on-pure-dc-power/

 

[DarrylG]

Or just purchase a small UPS device that works with a 12v battery inside (or whatever your setup is) and connect to your own battery. Still running the Starlink and Drobo on 120v

But you are correct. I have converted all of my IOT to run on 12 volts. For the two oddball devices I purchased a 48 volt DC-DC converter and a 5 volt DC-DC converter to make them play nicely.

 

[TorC]

Read through that article. If I read right, you don't need to cut any of the Starlink cables. Just have to make up your own special patch cables for the PoE injector because they used standard ethernet with a non-standard PoE power scheme.

That's actually a very trivial pair of cables to make for anyone with network wiring tools. Sounds like some newer SL dishes may use something different, however.

 

[CaptainPalapa - DWO]

Read through that article. If I read right, you don't need to cut any of the Starlink cables. Just have to make up your own special patch cables for the PoE injector because they used standard ethernet with a non-standard PoE power scheme.

That's actually a very trivial pair of cables to make for anyone with network wiring tools. Sounds like some newer SL dishes may use something different, however.

I have the newest flat-faced Dishy McDishFace or whatever they call it! Heh.
Yeah, I miss my RJ11 and RJ45 toolkit. I do NOT miss getting cat5/6 straightened out to squeeze into the little plugs. Ha ha ha.

 

[CaptainPalapa - DWO]

Read through that article. If I read right, you don't need to cut any of the Starlink cables. Just have to make up your own special patch cables for the PoE injector because they used standard ethernet with a non-standard PoE power scheme.

That's actually a very trivial pair of cables to make for anyone with network wiring tools. Sounds like some newer SL dishes may use something different, however.

Also, part of the "cut the cable" (for me) is I want an IP65 RJ45 port on the outside of the rig.

 

[TorC]

You can buy IP 65 or even IP 67 RJ-45s. Perhaps they also used a fully non-standard cable gland type on the SL, however.

https://www.discount-low-voltage.com/krj45ig-c6c is one potential option, and mating pairs are available.

 

[CaptainPalapa - DWO]

You can buy IP 65 or even IP 67 RJ-45s. Perhaps they also used a fully non-standard cable gland type on the SL, however.

https://www.discount-low-voltage.com/krj45ig-c6c is one potential option, and mating pairs are available.

I kinda like this one, for the use I need. https://smile.amazon.com/Shielded-Industrial-Bulkhead-Waterproof-Connector/dp/B07V317BYF/