Looking to add battery back up to house

[BORIStheBLADE1]

New guy here!
I've been reading through this forum for a while and decided to register to ask some questions.
I recently lost my father and trying to provide my mother with back up power that's as simple as possible. She is in her 70's and doesn't know how to start a generator.

I've been in the electrical field for about 20 years, but have never installed solar or the components for it. I've been doing research and where I need assistance is understanding what to look for in an inverter. I'm looking to just have power for the fridge and lights when the grid is down. I'm looking at getting an automatic transfer switch like this https://norwall.com/products/Champi...enter-Nema-1-Automatic-Transfer-Switch-100947 The lights are all LED which doesn't draw much. I don't need a split phase set up from what I see but open to it.

Right now with all the lights on in the house the total draw is 720 watts and the fridge idles around 150 watts with a peak of 650 watts.

Budget is about 5-7k and shooting for a 48v system.

Also the home she's in has arc fault breakers which I've seen be very sensitive. Does anyone have experience with the breakers and swapping over to battery back up power?

 

[MisterSandals]

Right now with all the lights on in the house the total draw is 720 watts and the fridge idles around 150 watts with a peak of 650 watts.

Do you know watt hour use per day and have a plan for number of days without sunshine this needs to handle as a backup?

Are there battery freeze possibilities or do you have a lead acid or lithium preference?

With this, its pretty easy to figure out how big. With your budget, quite a few folks can suggest options.

 

[Zapper77]

Simple as possible.

Generic UPS for a light.

 

[BORIStheBLADE1]

Do you know watt hour use per day and have a plan for number of days without sunshine this needs to handle as a backup?

Are there battery freeze possibilities or do you have a lead acid or lithium preference?

With this, its pretty easy to figure out how big. With your budget, quite a few folks can suggest options.

The fridge is averaging 2-4kWh a day. I don't have numbers for the lights. I would like to get her 24 hours at the least of back up.
Yes we get freezing temps and the garage can be over 100 during the summer. I don't have a battery preference and would probably need to look into the pros and cons. Do inverters come with battery tech requirements?

 

[MisterSandals]

The fridge is averaging 2-4kWh a day.

So what do we size for? Thats a 100% difference from 2kWh to 4kWh.

Do inverters come with battery tech requirements?

No solar mentioned so assuming grid charged.
The inverter will have a battery voltage compatibility spec as well as a charging amps spec. Sounds like charging amps can be low if not preparing for back to back outages.

Battery pros and cons (many existing discussions):

Search results for query: lithium vs lead

diysolarforum.com

 

[BORIStheBLADE1]

So what do we size for? Thats a 100% difference from 2kWh to 4kWh.


No solar mentioned so assuming grid charged.
The inverter will have a battery voltage compatibility spec as well as a charging amps spec. Sounds like charging amps can be low if not preparing for back to back outages.

Battery pros and cons (many existing discussions):

Search results for query: lithium vs lead

diysolarforum.com

Yeah it is a huge difference. There is nothing wrong with sizing for the 4k. I over build things anyways haha.

 

[MisterSandals]

I would like to get her 24 hours at the least of back up.

4kWh fridge and 1kWh lights...?

5000Wh / 12.8V = 391Ah battery (double this for lead acid, only 50% dischargeable)

with a peak of 650 watts.

Probably good with 1200W inverter. The trick will be finding one small enough (low idle power consumption if important) that can be hard wired to your ATS.

 

[BORIStheBLADE1]

4kWh fridge and 1kWh lights...?

5000Wh / 12.8V = 391Ah battery (double this for lead acid, only 50% dischargeable)


Probably good with 1200W inverter. The trick will be finding one small enough (low idle power consumption if important) that can be hard wired to your ATS.

If I went with 48v batteries that's just over 104Ah. From what I've read on here best practice is to run two batteries?

 

[MisterSandals]

If I went with 48v batteries that's just over 104Ah. From what I've read on here best practice is to run two batteries?

Yes you can use whatever voltage suits you. There are a lot of pros and cons between 12V and 48V. The watt hours are the key metric.
I am not sure how you'd find/choose a 48V inverter, that can be hard wired, that is right-sized for a 650W max load.
Regarding best practice, not sure why 2 batteries would be preferred over 1 battery other than redundancy.

 

[sonnyandsolar]

New guy here!
I've been reading through this forum for a while and decided to register to ask some questions.
I recently lost my father and trying to provide my mother with back up power that's as simple as possible. She is in her 70's and doesn't know how to start a generator.

I've been in the electrical field for about 20 years, but have never installed solar or the components for it. I've been doing research and where I need assistance is understanding what to look for in an inverter. I'm looking to just have power for the fridge and lights when the grid is down. I'm looking at getting an automatic transfer switch like this https://norwall.com/products/Champi...enter-Nema-1-Automatic-Transfer-Switch-100947 The lights are all LED which doesn't draw much. I don't need a split phase set up from what I see but open to it.

Right now with all the lights on in the house the total draw is 720 watts and the fridge idles around 150 watts with a peak of 650 watts.

Budget is about 5-7k and shooting for a 48v system.

Also the home she's in has arc fault breakers which I've seen be very sensitive. Does anyone have experience with the breakers and swapping over to battery back up power?

Not sure if you would be interested... But I have a new battery back-up system that I would sell to you in your budget. It is a Q-Home 7.6kWh inverter with two 4.5kWh (9kWh) batteries. I would love to help you and your mom out and see it get put to good use.