DIY battery backup

Spicy Reef · Jan 31, 2022

So this is basically my battery backup plan.
I have
Solar trickle charged
Leaf car battery's - used ebay
inverter that goes to a switch by the mains panel
refrigerator, tv, computer, radiant whole house gas heater/boiler, and aquarium all have access to this power.
With all this plugged in and running I might squeeze 12-24 hours.
I also have ryobi inverter with plenty of batteries for my water movement and filtration.
I'm currently working on adding a switch to make it a seamless transfer of power if I'm away.
Here's the intro...
still looking for more efficient (no inverter) solution to heat the water.

Jekyl · Jan 31, 2022

My recommendation is always a portable whole home generator. 5 or $600 and you can take care of everything instead of just the tank.

theatrus · Jan 31, 2022

Spicy Reef said:
So this is basically my battery backup plan.
I have
Solar trickle charged
Leaf car battery's - used ebay
inverter that goes to a switch by the mains panel
refrigerator, tv, computer, radiant whole house gas heater/boiler, and aquarium all have access to this power.
With all this plugged in and running I might squeeze 12-24 hours.
I also have ryobi inverter with plenty of batteries for my water movement and filtration.
I'm currently working on adding a switch to make it a seamless transfer of power if I'm away.
Here's the intro...
still looking for more efficient (no inverter) solution to heat the water.

Disclaimer: didn't watch a 15min video

A leaf battery pack is a 350V device, so be extremely careful. HVDC is a whole other ball game compared to AC from a safety perspective (you will _not_ let go if you grasp a HVDC connection, assuming the arc flash doesn't get you first). If you part it out to the various lower voltage modules, that will also help in the power conversion front.

As for heating, resistive heaters (WITHOUT THERMOSTATS) could care less if powered by DC or AC. They're just resistors. If you're at higher voltages, just string several in series to get back to the nominal power.

Spicy Reef · Feb 1, 2022

Jekyl said:
My recommendation is always a portable whole home generator. 5 or $600 and you can take care of everything instead of just the tank.

Agreed

I'm kind of a numb nuts when it comes to SMALL gas engines, I'm great with cars. rebuild MGB, VW Bug, and work all the time on my ford ranger.
I Had a gas lawn mower had to take in twice a year, pain in the ars! So happy when I they started making electric mowers.
Love the lithium-ion leaf batteries. I've had them for 4 years now, we get an outage at least once every year during the windstorms.
what generator do you have that can power the whole house or at least everything I'm powering?
Does it have built-in inverter?
how long does a tank of gas last?
Thanks

Spicy Reef · Feb 1, 2022

theatrus said:
Disclaimer: didn't watch a 15min video

A leaf battery pack is a 350V device, so be extremely careful. HVDC is a whole other ball game compared to AC from a safety perspective (you will _not_ let go if you grasp a HVDC connection, assuming the arc flash doesn't get you first). If you part it out to the various lower voltage modules, that will also help in the power conversion front.

As for heating, resistive heaters (WITHOUT THERMOSTATS) could care less if powered by DC or AC. They're just resistors. If you're at higher voltages, just string several in series to get back to the nominal power.

I must come off as an imbecile to you

My Leaf batteries are 51.8v and yes even that packs a punch!
My 48V panels as you probably know put out 75V (that's solar for you)
My 48V inverter works up to 57V

Why would anyone run a heater w/o thermostat?
I was asking if anyone is running them w/o inverter, straight DC?
Thanks for checking in. Ask me anything, no need to watch a 15-minute vid

Jekyl · Feb 1, 2022

Spicy Reef said:
Agreed
I'm kind of a numb nuts when it comes to SMALL gas engines, I'm great with cars. rebuild MGB, VW Bug, and work all the time on my ford ranger.
I Had a gas lawn mower had to take in twice a year, pain in the ars! So happy when I they started making electric mowers.
Love the lithium-ion leaf batteries. I've had them for 4 years now, we get an outage at least once every year during the windstorms.
what generator do you have that can power the whole house or at least everything I'm powering?
Does it have built-in inverter?
how long does a tank of gas last?
Thanks

I have an 8500w portable generator I keep in the garage with 3 6gal gas cans full with a splash of seafoam in each. Keeps the gas good when not being used. I also have a 220 outlet in the garage. Any time the power is out I shut off my main breaker in the house (very important) roll my generator outside (also very important) start it and plug it in the the 220 outlet. Powers my whole house including A/C and fridge. Think I paid about $800 for it. Could have went smaller but didn't want any issues.

DopamineKata · Feb 1, 2022

theatrus said:
As for heating, resistive heaters (WITHOUT THERMOSTATS) could care less if powered by DC or AC. They're just resistors. If you're at higher voltages, just string several in series to get back to the nominal power.

I've wondered if those Helios PTC heaters would be easier on a battery/inverter setup?

YOYOYOReefer · Feb 1, 2022

why not just run a titatinum heat exchanger off your boiler system, use a peristatltic pump to drive it based off temp.

or just plug your heater into your inverter and eat the conversion energy just like you are with everything else plugged into the inverter.,, what inverter are you running?

theatrus · Feb 1, 2022

Spicy Reef said:
I must come off as an imbecile to you
My Leaf batteries are 51.8v and yes even that packs a punch!
My 48V panels as you probably know put out 75V (that's solar for you)
My 48V inverter works up to 57V

Why would anyone run a heater w/o thermostat?
I was asking if anyone is running them w/o inverter, straight DC?
Thanks for checking in. Ask me anything, no need to watch a 15-minute vid

Ok, so its not entire leaf pack, its the modules, which is fine. Whole packs are strung at 350V for traction, and its not uncommon for battery "powerwall"esque products to be configured the same.

> Why would anyone run a heater w/o thermostat?

The thermostat is external. The heaters with built-in bi-metallic thermostats are designed for AC, and they could not break DC reliably (it has no zero crossing to extinguish the arc, so would just arc-weld its self closed). Switching DC requires other methods - solid state is fine.

> I was asking if anyone is running them w/o inverter, straight DC?

If you had 120V DC, yes, absolutely. Grab a BRS titanium heater core (w/o thermostat), stick 120V to it, success. At 48V, you'd need ~4x+ as many in parallel to get the same power, which is viable but not cheap and kinda wastes space. They're just resistors in a box. There are probably other heater cores which can be used, but its probably simpler to just string two battery modules in series on discharge to the heaters.

Spicy Reef · Feb 1, 2022

YOYOYOReefer said:
why not just run a titatinum heat exchanger off your boiler system, use a peristatltic pump to drive it based off temp.

or just plug your heater into your inverter and eat the conversion energy just like you are with everything else plugged into the inverter.,, what inverter are you running?

heat exchanger... that would be a fun project

not for me though...

Ur right, when it comes down to it, I run the aquarium heaters off the inverter. My hope is to get away from that and keep the reef separate. Not because I have to, but only to make it clean for anyone to replicate.

My son made a sous vide "heater" that runs off a battery no inverter everything DC. It looks very simple so I'm surprised no one has come up with one for the reef.

Also, pushing it to run the heaters off this inverter... takes a lot of juice

Thanks for the suggestions

Stang67 · Mar 7, 2022

Jekyl said:
I have an 8500w portable generator I keep in the garage with 3 6gal gas cans full with a splash of seafoam in each. Keeps the gas good when not being used. I also have a 220 outlet in the garage. Any time the power is out I shut off my main breaker in the house (very important) roll my generator outside (also very important) start it and plug it in the the 220 outlet. Powers my whole house including A/C and fridge. Think I paid about $800 for it. Could have went smaller but didn't want any issues.

I am getting a transfer switch installed myself. I assume that will mean I don't require the inverter style gene? Is the 8500 starting or running power?