Is there such a thing as a 12v UPS?

[BigFatGuy]

You can get a UPS (Uninterruptible Power Supply) for computers/tvs, etc that charge an internal battery off of the 120V mains, and provide the equipment with a stable 120V environment, even in the event of power failures.

Is there such a thing in the 12V world? A capacitor bank isn't really the same, and i could build my own... but I'd have to dig up my power supply design textbooks from college... I'm not that kind of electrical engineer.

Does such a thing exist, commercially?

[hbn7hj]

It is called a battery! You already have one.

[BigFatGuy]

A battery is only part of it

[Bud]

Originally Posted by BigFatGuy

A battery is only part of it

I think that I understand. A solution that I use, but did not realize it until now as my application was not yours. My application was for the refrigerator.

I don't recall the exact circumstances, but avanti is responsible for me having this solution. This is what you can do.

Purchase a ATS. I used this one per avanti:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Then I simply plugged in ac from a 110 ac outlet which was priority (shore power, then generator). Also plugged in ac from the inverter. The output was this:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

With individual switches I can turn off the tv (standby power is off) along with everything else like the outside tv antenna amplifier, sat receiver, computer etc. But the refer always stays on, so I better be running the van's engine sooner rather than later or switch to propane.

This seems like it would work for your application.

Bud

[BigFatGuy]

Let me describe what I'm trying to do in a bit more detail:

The "house" stereo, fridge, and any other electronics I install in my "media cabinet" are fed by 12V battery power.

This "12V" power fluctuates between 11V and 14.4V on a regular basis. It also frequently "glitches" when I, for instance, start the generator or plug into 120V mains.

I've gone through 3 fridge controller boards in 2 years, and my stereo turns off every time I get one of these 12V "glitches"... so I'm convinced the people who design the electronics in the RV did not fully account for the unstable power environment.

I'd like to install a device that would take in this "dirty", glitchy 12V power, use it to charge a small alarm-system-type battery, and use that battery to supply a clean, stable 12V output to a small number of devices.

In the 120V world, this is an off-the-shelf item called a "UPS".

In the 12V world, it looks like I may have to design my own... but I'd rather buy something that already exists.

EDITED TO ADD:

I may, in the end, just stick a big bank of capacitors (from the car audio world) in line with the 12V charger... it'll be cheaper and simpler, and should provide most of the glitch protection I'm looking for...

[Bud]

Originally Posted by BigFatGuy

Let me describe what I'm trying to do in a bit more detail:

The "house" stereo, fridge, and any other electronics I install in my "media cabinet" are fed by 12V battery power.

This "12V" power fluctuates between 11V and 14.4V on a regular basis. It also frequently "glitches" when I, for instance, start the generator or plug into 120V mains.

I've gone through 3 fridge controller boards in 2 years, and my stereo turns off every time I get one of these 12V "glitches"... so I'm convinced the people who design the electronics in the RV did not fully account for the unstable power environment.

I'd like to install a device that would take in this "dirty", glitchy 12V power, use it to charge a small alarm-system-type battery, and use that battery to supply a clean, stable 12V output to a small number of devices.

In the 120V world, this is an off-the-shelf item called a "UPS".

In the 12V world, it looks like I may have to design my own... but I'd rather buy something that already exists.

EDITED TO ADD:

I may, in the end, just stick a big bank of capacitors (from the car audio world) in line with the 12V charger... it'll be cheaper and simpler, and should provide most of the glitch protection I'm looking for...

Your application appears to Not be the usual UPS application. You want it for 'nice' ac power from your rv batteries. Why not fix the lousy ac power from the batteries? The power to my computer, etc. no matter source from the ATS switch is not lousy with qlitchy dirt power, no problems.

I suppose that I'm still not understanding, sorry.

[BigFatGuy]

Originally Posted by Bud

Your application appears to Not be the usual UPS application. You want it for 'nice' ac power from your rv batteries. Why not fix the lousy ac power from the batteries? The power to my computer, etc. no matter source from the ATS switch is not lousy with qlitchy dirt power, no problems.

I suppose that I'm still not understanding, sorry.

DC. I want to clean up the DC power environment. Most of my rig never sees AC at all.

I cannot "clean up" the DC environment properly for several reasons:

1. A lot of the issues are simply the way the RV works... the 14.4V periods, for instance, are a regular battery-maintenance feature of the charger. the 11V periods are the batteries running low.
2. Replacing the solar charger, the 120V charger, the auto-crossover, AND the generator would be expensive, and will likely not fix the "glitches"
3. in your RV, the 120V environment might, indeed, be quite clean... because you don't have many 120V devices on that line. Put an oscope on your house's 120V line in a major urban center, and see how dirty the power can really be.

[markopolo]

12V DC direct from a battery should be clean power. That might not be the case when the charger is running though. Sometimes the DC distribution panel will have filtered and not filtered outputs.

Voltage variance is normal but 11V is really low when inverter use is excluded.

You could check all connections and grounds. See if you notice any areas of heat that would indicate high resistance due to a poor connection.

[booster]

When we were using a 110v tv that used a 12v wall brick, which we removed, we used a 12v stabilizer to assure the voltage and cleanliness of the power was good. I think the brand was Amperon of near that. I don't know if they had larger versions of that product line, but it sounds like what you are looking for.


On edit--I think this is what you want, all the way up to 50 amps.




https://www.poweringthenetwork.com/d...r-stabilizers/

[Bud]

Originally Posted by booster

When we were using a 110v tv that used a 12v wall brick, which we removed, we used a 12v stabilizer to assure the voltage and cleanliness of the power was good. I think the brand was Amperon of near that. I don't know if they had larger versions of that product line, but it sounds like what you are looking for.


On edit--I think this is what you want, all the way up to 50 amps.




https://www.poweringthenetwork.com/d...r-stabilizers/

booster, thanks for taking care of me and much ignorance. If I understand: With my 190P vs your 'old' 190P, when connected to shore power or generator the battery switch can be off and the 12 volt stuff is using the converter while you have to had the battery turned on? right? IF so, were you then using the converter or battery for the 12 volt stuff?

[booster]

Originally Posted by Bud

booster, thanks for taking care of me and much ignorance. If I understand: With my 190P vs your 'old' 190P, when connected to shore power or generator the battery switch can be off and the 12 volt stuff is using the converter while you have to had the battery turned on? right? IF so, were you then using the converter or battery for the 12 volt stuff?

I think yours is an 04/05? maybe, if so we are a bit newer at 07/07


On ours, which was one of the first with a wiring change for the charger circuit, the charger is on the same side of the 12v power relay as the batteries are. One earlier versions the batteries were on one side of the switch and the charger was on the load (coach) side of the relay. Yours would have been like that and you would need to have the 12v relay on to get the charger to run and charge the batteries. All of the post 2003 Chevies came with chargers that won't run unless they can see a battery in the circuit I think, so there would be no way to run the coach off the charger with batteries shut off. On the later ones like ours, if you have added something that runs right off the batteries, you would be able to run that item without having the coach 12v power relay on, but nothing else.



To run the coach without a battery in the circuit you would need to have a regulated 12 power supply. AFAIK, the only ones that are used for RVs currently are the Progressive Dynamics units as they can be run at a fixed 13.6v without a battery in the circuit, if they have that provision in the unit you have. If you go way back to the time frame of dedicated "converters" in RVs, I think some of them may have been OK without a battery, but I am not certain on that.

[BigFatGuy]

Originally Posted by markopolo

That might not be the case when the charger is running though.

Which, in my RV, occurs whenever the sun is up, the rig is plugged into mains power, or the generator is running.

Originally Posted by markopolo

Voltage variance is normal but 11V is really low when inverter use is excluded.

11V basically means the batteries are run down, and my fridge is on the verge of shutting off. It's not good, it's not common, but it happens. The problem with a compressor-only fridge and AGM batteries is: if I crank the fridge to "7" while boondocking my batteries will be dead by morning.

Originally Posted by booster

On edit--I think this is what you want, all the way up to 50 amps.
https://www.poweringthenetwork.com/d...r-stabilizers/

That's almost exactly what I'm looking for. Thank you!

[markopolo]

Originally Posted by booster

.................... All of the post 2003 Chevies came with chargers that won't run unless they can see a battery in the circuit...............

Maybe all .......... except Bud's. His didn't come with a Tripp Lite for some reason.

[booster]

Originally Posted by markopolo

Maybe all .......... except Bud's. His didn't come with a Tripp Lite for some reason.

Yep, I couldn't remember which one he had though to check for sure that it wouldn't run without a battery or not. It must have been whatever they had been using in the Dodges at the end of their run.

[hbn7hj]

You need a voltage stabilizer. I use Amperor but I can’t find a link for you. Output voltage is a stabilized 12.6 volts and works very well. Output is 10 amps which covers everything that is voltage sensitive. I have had no trouble with the refrigerator control board voltage not being stabilized. If you are interested in Amperor I’ll look harder but most I found are 18.5 volts for computers. I expect the 12.6 volt version is available. I just haven’t found it.

Even with it my TV system will not survive a generator start. For that I switch to the lithium system and all is well. The generator starts from the FLA system. I don’t think I would want a stabilized system at 13.6 but it worked well for booster.

I haven’t had the need to put a battery between the stabilizer and load but you can try it. It could smooth out a generator start. Don’t think you would want it charged at 13.6 volts for an indefinite time.

This will work for a 12 volt TV but nothing more.
https://www.amazon.com/Jili-Online-C.../dp/B078QJWYLH

A hybrid system would solve all your problems!

[booster]

Originally Posted by hbn7hj

You need a voltage stabilizer. I use Amperor but I can’t find a link for you. Output voltage is a stabilized 12.6 volts and works very well. Output is 10 amps which covers everything that is voltage sensitive. I have had no trouble with the refrigerator control board voltage not being stabilized. If you are interested in Amperor I’ll look harder but most I found are 18.5 volts for computers.

Even with it my TV system will not survive a generator start. For that I switch to the lithium system and all is well. The generator starts from the FLA system. I don’t think I would want a stabilized system at 13.6 but it worked well for booster.

I haven’t had the need to put a battery between the stabilizer and load but you can try it. It could smooth out a generator start. Don’t think you would want it charged at 13.6 volts for an indefinite time.

This will work for a 12 volt TV but nothing more.
https://www.amazon.com/Jili-Online-C.../dp/B078QJWYLH

I think this is what you are talking about, but not 10 amps. This is the one we had IIRC.


https://www.amperordirect.com/pc/c-P...090-D1000.html

[hbn7hj]

Originally Posted by booster

I think this is what you are talking about, but not 10 amps. This is the one we had IIRC.


https://www.amperordirect.com/pc/c-P...090-D1000.html

Yep, it is tuff being senile. Anyhow, it works very well.

[rowiebowie]

Voltage stabilizer = lithium batteries.

I know this is what the OP eventually wants, so it might not be cost effective to spend much on his immediate 12v problem. Especially since it appears to be related to his need to increase overall battery capacity.

[booster]

Originally Posted by rowiebowie

Voltage stabilizer = lithium batteries.

I know this is what the OP eventually wants, so it might not be cost effective to spend much on his immediate 12v problem. Especially since it appears to be related to his need to increase overall battery capacity.

All batteries smooth power a bit, but I can tell you that you can see the ripple from an alternator, MPPT solar controller, most chargers, etc with a scope or sometimes even with an AC multimeter. Lithiums high acceptance probably helps some, but I doubt is would do a lot more for superimposed noise or spikes, especially if it kicked in the lithium setup self protection stuff. Where did you get information that says that a lithium bank can take the place of a stabilizer or power conditioner?

[MobileCabin]

Back to the original question. In addition to the Newmar product mentioned by booster, they have another with an internal battery for those momentary no power events. It might be closer to what is needed for this application:

https://powerwerx.com/newmar-mdp-25-...s-backup-power

I would like to hear from anyone who has used it.