Off grid solar, bummer.

[venquessa]

Last month I had a 50W panel and a 12V lead acid battery. A kinda hobby project that "stuck" and I kept using it to charge my phone, and anything battery operated I could find and in winter charge the battery to keep it alive.

Audio related. An ungrounded, floating, leadacid is a VERY quiet power source. Even when you put it through a boost/buck convertor to get a stable 16V, it's amazingly quiet.

This month, I upgrade to a 330W panel and 1.5kWh of LiFePO4 (105Ah). The panel is now fully charging the battery with the current load even on cloudy days.

So I started adding anything that would accept a 12V DC barrel jack into the solar circuit. Network switches, routers, USB hubs.

Now my audio sucks

I could try and fix that, but next month I intend to install an inverter. As far as I see it, that's the end of my quiet DC power source

The plan... throw some LiFePO4 18650 cells together as a buffer pack I can disconnect from the main rail to run just my audio rail.

Of I could learn how to properly filter the common mode USB noise off my power rails.

 

[Timcognito]

My solar panels, inverter, Tesla Powerwall II runs dead quiet for 20 hours when full, running lights, two refrigerators, and and OLED TV. Can't use the electric dryer or oven though, then about 7 hours..

 

[venquessa]

Slight difference. Your system is only mains voltage. What I am working with would be what you would only see if you put a scope on the power wall's DC terminals.

 

[venquessa]

Mains noise itself with inverter versus grid versus hybrid (of various flavours). I would have little experience and few ideas. One thing is pretty much guaranteed is some form of isolation between the mains and DC. Even if that regrettably includes mains leakage via the Y class feedback of anti-EMI caps on the SMPSU. So, given the mains is being switched at over (sometimes 300kHz) into a big cap, does noise on the mains noise really matter on DC LV systems?

 

[Chrise36]

Last month I had a 50W panel and a 12V lead acid battery. A kinda hobby project that "stuck" and I kept using it to charge my phone, and anything battery operated I could find and in winter charge the battery to keep it alive.

Audio related. An ungrounded, floating, leadacid is a VERY quiet power source. Even when you put it through a boost/buck convertor to get a stable 16V, it's amazingly quiet.

This month, I upgrade to a 330W panel and 1.5kWh of LiFePO4 (105Ah). The panel is now fully charging the battery with the current load even on cloudy days.

So I started adding anything that would accept a 12V DC barrel jack into the solar circuit. Network switches, routers, USB hubs.

Now my audio sucks

I could try and fix that, but next month I intend to install an inverter. As far as I see it, that's the end of my quiet DC power source

The plan... throw some LiFePO4 18650 cells together as a buffer pack I can disconnect from the main rail to run just my audio rail.

Of I could learn how to properly filter the common mode USB noise off my power rails.

Make two different systems. There are also ready made low voltage battery ups

 

[venquessa]

What I am facing is "FzzTcTcTcFzzzzzTcTcTc" noise from the USB and the huge amount of crap a gaming PC rig will dump onto the grounds, causing it to bounce. You can "hear the mouse move".
Also the whine of a boost or buck covertor or the PSU in a network switch.
DC power rails, in the wild are.. wild. Common mode noise and ground in balance create huge headaches.

 

[venquessa]

The inverter is upstream so it only sees AC.

What? The power wall is a block of DC batteries. If you put AC into it, it will explode. I don't mean the AC feed INTO the powerwall I mean the + - terminals on it's battery terminals. You'd need to open it to find them.

See "Off grid Garage" on YouTube.

 

[Chrise36]

What I am facing is "FzzTcTcTcFzzzzzTcTcTc" noise from the USB and the huge amount of crap a gaming PC rig will dump onto the grounds, causing it to bounce. You can "hear the mouse move".
Also the whine of a boost or buck covertor or the PSU in a network switch.
DC power rails, in the wild are.. wild. Common mode noise and ground in balance create huge headaches.

It is because they are in the same system. Isolate your audio gear from the rest.

 

[venquessa]

I note. Tesla power wall, 7kWh, £7000 + install + accessories + shipping + VAT =>£1000 per kWh. Wholesale LiFePO4 batteries < £200 per kWh. + expenses... granted very expensive ones.

No right or wrong, just a balance of cost and convenience. Tesla Powerwall is not the only ones at it. Most "House batteries" are priced abotu 4 to 10 times their actual value in parts.

 

[venquessa]

It is because they are in the same system. Isolate your audio gear from the rest.

Yes. A bit of a captain obvious statement.

However. Define "system".

Look I'll be fair on you. In reality you are absolutely correct. To restore my nice quiet DC rail, I just need to put a sizable enough battery to supply a few days of isolated DC power for "analog side" devices like amps, headphones, audio processors, speakers. I can connect and charge that battery when I'm not using it for audio.

 

[Timcognito]

Slight difference. Your system is only mains voltage. What I am working with would be what you would only see if you put a scope on the power wall's DC terminals.

 

[Timcognito]

I note. Tesla power wall, 7kWh, £7000 + install + accessories + shipping + VAT =>£1000 per kWh. Wholesale LiFePO4 batteries < £200 per kWh. + expenses... granted very expensive ones.

No right or wrong, just a balance of cost and convenience. Tesla Powerwall is not the only ones at it. Most "House batteries" are priced abotu 4 to 10 times their actual value in parts.

In California my time to free electricity is 6-1/2 years, on target after 2-1/4 years at current rates. Could be less if rates go up. My house was a net electricity producer in 2022 by the slimmest of margins.

 

[Zapper]

You need a power line EMI filter. A passive low pass filter to attenuate all that electronic noise.