Battery Backup Options?

I live in California and it looks like we may be having scheduled, multi-day power outages this summer due to PG&E's history of poor management/maintenance of our power grid.

Therefore, I'm looking at a battery backup and would appreciate any advice from the forum. I plan to recharge the battery during the day using the solar panels already installed on our roof or in a pinch, my Prius

I have a Resmed Airsense Auto (don't use the humidifier) with a Resmed Airfit N20 mask.

Any and all ideas re: batteries, adapters, etc. gratefully accepted .

rshev wrote: ↑

Wed Jul 24, 2019 11:24 am

I live in California and it looks like we may be having scheduled, multi-day power outages this summer due to PG&E's history of poor management/maintenance of our power grid.

Therefore, I'm looking at a battery backup and would appreciate any advice from the forum. I plan to recharge the battery during the day using the solar panels already installed on our roof or in a pinch, my Prius

I have a Resmed Airsense Auto (don't use the humidifier) with a Resmed Airfit N20 mask.

Any and all ideas re: batteries, adapters, etc. gratefully accepted .

Everything I know is in this thread:
viewtopic/t114012/Choosing-a-Battery.html
The good stuff is on the first page - the first dozen or so posts.

Your pump, without humidity, uses roughly 8 amp-hours a day from a 12V battery. You'll need a ResMed 12/24 volt converter. The battery I generally recommend is the "U1" size, which is 35 amp-hours, which would be good for 3 nights, but you could go up or down from there depending on your anticipated needs. If you really expect multi-day power outages, you might be planning for powering cell phones and other appliances.

rshev wrote: ↑

Wed Jul 24, 2019 11:24 am

I live in California and it looks like we may be having scheduled, multi-day power outages this summer due to PG&E's history of poor management/maintenance of our power grid.

Therefore, I'm looking at a battery backup and would appreciate any advice from the forum. I plan to recharge the battery during the day using the solar panels already installed on our roof or in a pinch, my Prius

I have a Resmed Airsense Auto (don't use the humidifier) with a Resmed Airfit N20 mask.

Any and all ideas re: batteries, adapters, etc. gratefully accepted .

welcome to the zoo!

please see this post-

viewtopic/t114012/Choosing-a-Battery.ht ... +a+battery

or wait for capnloki to come by to answer your question.

good luck!

rshev wrote: ↑

Wed Jul 24, 2019 11:24 am

I live in California and it looks like we may be having scheduled, multi-day power outages this summer due to PG&E's history of poor management/maintenance of our power grid.

How many is "multi"?

rshev wrote: ↑

Wed Jul 24, 2019 11:24 am

Therefore, I'm looking at a battery backup and would appreciate any advice from the forum. I plan to recharge the battery during the day using the solar panels already installed on our roof or in a pinch, my Prius

You have solar panels but no batteries?
Is this a grid tie system?
Hope its not a Tesla system, confirm?

First, thanks sooo much for the prompt and most thorough responses. There is much to digest and learn from.

Jack, to answer your questions, Pacific Graft & Extortion just says they don't know, but "it could be up to a week". It has to do with needing to inspect each of the unpowered the lines for damage after the winds before power is restored.

As to the solar panels, yes, it is a tie-in to the grid with an LG battery as backup. My hope is that with judicious economizing, I might be able to get a full night with the LG and then recharge the next day. Sadly, the LG is of somewhat limited capacity and so I may need additional power for my CPAP--thus my question on this forum. Even the Tesla battery (which I looked at), could at most do 1.5 days before going dead. It added major cost to the system and I could not justify it. Also, it is now in short supply and may not be possible to even get in time.

rshev wrote: ↑

Wed Jul 24, 2019 4:07 pm

...
As to the solar panels, yes, it is a tie-in to the grid with an LG battery as backup. My hope is that with judicious economizing, I might be able to get a full night with the LG and then recharge the next day. Sadly, the LG is of somewhat limited capacity and so I may need additional power for my CPAP--thus my question on this forum. ...

Ah ... the plot thickens! You actually have a small off-grid system but having thoughts that it might not be enough and you should have a backup for the backup! The real answer of course is simply make the off grid system big enough - but that is easier said than done.

So the "backup for the backup" is easy. Get a 100 amp-hour AGM (about $180). The 5 or 6 amp BatteryTender should handle it if you can't use the solar. This should cover 7 nights at 8 amp-hours per night with a fair margin. Or get 3 of the U1 (35ah) batteries so you can carry them easier. Or get a 100 and 35 so you have a backup for the backup for the backup. (I'm only being slightly sarcastic - I'm a "belt and braces" guy!)

BTW, on my boat I live off grid - 350 watts of solar and a 480 amp-hour house bank support a small fridge, several computers, phones, lights, fans, microwave, and my cpap. I have a few alternate charge options but haven't had to use them this summer. My theory is to make the house system, which I rely on everyday, overkill - at least enough to run 3 days while inhabited with no sun, 5-7 days uninhabited.

rshev wrote: ↑

Wed Jul 24, 2019 4:07 pm

...it is a tie-in to the grid with an LG battery as backup.

It is my understanding that typically grid tie inverters don't deliver power when they don't "see" poco power to synchronise with. The reason I mention Tesla is they have a further dependency on an internet connection back to the mother ship.

For outages of up to a week I would be looking at keeping other things running also.
Think fridge, freezer, well pump , sump pump, etc.

Good batteries - https://battlebornbatteries.com/product ... batteries/
Fuel cell - https://www.efoy-comfort.com/which-model

The batteries are expensive.
The fuel cell is really expensive!
A generator is inexpensive by comparison.

Jack Burton wrote: ↑

Thu Jul 25, 2019 3:52 pm

rshev wrote: ↑

Wed Jul 24, 2019 4:07 pm

...it is a tie-in to the grid with an LG battery as backup.

It is my understanding that typically grid tie inverters don't deliver power when they don't "see" poco power to synchronise with. The reason I mention Tesla is they have a further dependency on an internet connection back to the mother ship.

For outages of up to a week I would be looking at keeping other things running also.
Think fridge, freezer, well pump , sump pump, etc.

Good batteries - https://battlebornbatteries.com/product ... batteries/
Fuel cell - https://www.efoy-comfort.com/which-model

The batteries are expensive.
The fuel cell is really expensive!
A generator is inexpensive by comparison.

Until you count in the cost of Fuel. Jim

I use a UPS as my emergency backup but its only good for around 1-2 hours. I have another battery backup that is DC to DC (Maxoak CPAP battery).

Nebraska gets cold, hot, wet, or snowy; and your house can blow away.
But our electricity is cheap and reliable.

Diotima wrote: ↑

Sun Jul 28, 2019 9:10 am

I use a UPS as my emergency backup but its only good for around 1-2 hours. I have another battery backup that is DC to DC (Maxoak CPAP battery).

If you want to make your UPS last a lot longer, tear out the inverter, and hook the cpap directly to the battery with the appropriate DC cable.

palerider wrote: ↑

Sun Jul 28, 2019 12:20 pm

Diotima wrote: ↑

Sun Jul 28, 2019 9:10 am

I use a UPS as my emergency backup but its only good for around 1-2 hours. I have another battery backup that is DC to DC (Maxoak CPAP battery).

If you want to make your UPS last a lot longer, tear out the inverter, and hook the cpap directly to the battery with the appropriate DC cable.

That sounds intense... It's also my main computers UPS during the day.