The beginnings of my battery bank, inverter station.

[Pepere]

Today I built the plywood case.





The height of it will allow me to have both the charger and inverter mounted on the back.

I also have a handhold cut into the top back, and will be installing an axle and a set of wheels on the back to move it around.

I had planned on wiring it up, but I found I ordered the wrong buss bars, so it will have to wait.

I will be mounting the buss bars on the case and I will have a class T fuse inline from. Batteries to buss bars on the which provides a 20,000 ampere interrupt capacity. (AIC) rating. For those who have not heard of AIC ratings, it means that the fuse will blow at nominal rating, in this case iirc I have a 125 ampere fuse, and it will not allow a spark to bridge the gap, up to 20,000 amps. Class T fuses have the highest AIC ratings and it is reccomended anytime you are working with Lithium batteries…

I have 2 100 amps hour Lithium Iron Phosphate batteries that combined will provide roughly 2.5 killowatt hours of power.

This will be used at our house to provide back up power to boiler when we dont want to run the generator. It is replacing an older setup that used 2 deep cycle lead acid batteries. We can also use it to boost fridge and or freezer, and have been known to get a load of dishes done in the dishwasher with it. It is recharged when the generator is running.

I will update with additional photos when the Buss Bars arrive and get installed…

I will grant you this is not as compact and professional looking as an all in one unit like the Ecoflows or Jackery or what not, but, I have spare fuses on hand, and if an inverter or charger goes, I simply replace that item. A couple screw and nuts and its done. No having to ship whole unit out somewhere…. If the batteries wear out or fail, I simply replace that component. I dont have to worry about the company going out of business and not being able to get replacement proprietary components and being mandated to have it repaired at an authorized service center…

 

[Phish Tank]

awesome setup. There is something quite nice about being able to control (and replace!) all the components going into a DIY system. And I bet 2.5kwh will power your aquariums for a nice long stretch.

 

[Pepere]

It is mostly done.

The battery charger has a quick disconnect so I am charging the batteries up while I am sitting by the unit. The wires from the charger is smaller than 4 guage so I will be installing an ANL fuse of 50 amps to protect the wire. It is on order and will be here next week.

First I installed some rigid caster wheels at the rear base to allow me to tilt it back and roll it around like carry on luggage. And I installed the inverter on the back of the unit.


I then installed a hot and neutral buss bar and a class T fuse and holder. Class T fuses have a 20,000 AIC rating which is the highest of any fuse. AIC stands for Ampere Interrupt Capacity.. in essence I have a 125 amp fuse. The fuse will blow at 125 amps nominal. Which means it blows at higher than 125…. I forget what the actual amperage is, . Iirc it may be 125% of rating…. There is a fudge factor with fuses and circuit breakers as well as safety factors in the ampacity of wires…. In any event this is the right size fuse for 4 guage wire. The AIC rating means that the fuse will not allow a spark to bridge the fuse ends up to 20,000 amps. When you play with lithium batteries the amount of amps that can flow is amazing. Use a Class T fuse if you are using Lithium batteries…



The LiFePO4 Power Queen batteries come with an owners manual. It recommends connecting the two positives together with a conductor and then a wire from each positive to your Buss Bar as well as the same with the neutrals.

I also installed MBRF fuse blocks on the positive terminals and the wires going to the Class T fuse is coming from the top of the MBRF fuses also 125 amps each. MBRF fuses have a 10,000 AIC rating. In my mind the redundancy is cheap insurance, but many might be of the opinion that it is overkill. It might be, but it is cheap enough…

Bear in mind this power station is a lot more than most aquarium owners would need. It has roughly 2 1/2 killowatt hours of power storage and 1500 watts of output.

If you are simply desiring to keep a canister filter running till power comes on, it is overkill…

A fluval 207 consumes 10 watts
A Fluval fx4 consumes 27 watts
An Oase biomaster 350 consumes 16 watts…

So, 240 watt hours a day for the 207
650 for the fx4
390 for the oase…

All of these would operate just fine on a cheapy 400 watt pocket inverter…. The key is still the capacity…. A deep cycle lead acid battery. For about $120.00 holds roughly 100 amp hours, or a little over a killowatt hour of electricity, but you dont want to discharge it too deeply. The deeper you discharge it the fewer charge recharge cycles you have. In the Rv and Marine world people generally try to avoid discharging more than 50%…. So around 500 to 600 watt hours before a recharge.

One of the biggest benefits of the LiFePO4 batteries have is the ability to pretty much fully discharge the battery and use the whole 100 Amp hours. The LiFePO4 batteries have built in to them Battery management devices that will shut them down once you have pulled all the power you safely can, or if it overheats or is subject to overcharging etc. etc…. They can be charged daily and discharged until the BMS shuts it down daily and will still retain 80% capacity after 20 years. Try that with deep cycle lead acid batteries and you will be replacing them several times a year…

 

[Pepere]

Oh my freaking goodness!

I shied away from the all in one proprietary units over the issue of being able to repair the thing…

Now they have given me a whole new reason to avoid them..

https://www.notebookcheck.net/EcoFlow-to-introduce-paywall-for-premium-features-on-power-solutions.953068.0.html

This scourgeof having to pay ongoing subscription to use an item we have paid for has to be stopped!

It will only stop when companies perceive lost sales are costing them more than they are raking in….

 

[Pepere]

In an earlier post above I mentioned the capacity and output of this is significantly higher than needed to run a filter or two for an aquarium.

This power station is used at the house to provide back up power for the boiler providing heat and hot water for my house.

Since last update to it I placed an additional ANL fuse between the buss bar and the charger. The wire was a bit smaller. When we install fuses or circuit breakers it is to protect the wires. We want to protect the wires from becoming igniters setting the house on fire. I also installed a Victron shunt inline between the negative buss bar and the negative battery posts. The shunt provides real time data on state of charge and power flows as well as a historical graph so you can see how full the battery is and how long it might last till needing a recharge. The shunt connects to your phone or tablet by bluetooth.

The battery charger is plugged into a Kasa wifi plug, so I can turn on the charger before a storm is set to start that might be a power outage event. I store the batteries at 50% capacity and only rechargeto 100% before a sizeable storm, either wind and rain event or Noreaster snow storm here in Maine. The timer allows me to have the charger on a countdown timer to have it charge for 3 hours which will bring the batteries from 50% to full.

We have a remote switch in the living space to turn the inverter on. The boiler is wired to plug into an outlet like an appliance. We have a switching device that is plugged in to grid power and into the inverter and the boiler is plugged into the device. So long as the grid is energized, the boiler gets its power from the grid. When grid power fails, both the neutral and hot conductor is switched to the inverter.
All we have to do in case of an outage is walk to the inverter remote and turn it on.


The current battery can keep the boiler going providing heat at 70 degrees in the house, and hot water for our needs for 4 days with outside temps averaging 0 degrees.

In the summer time we could keep both our fridge and freezer running and at temp for 2 days.

I also have a few generators for recharging the batteries and running other loads as needed.. it is nice to have the generator off all night and not droning in the background…

Where we live within city limits as a general rule run of the mill outages are under an hour or two. Large powerful storms with widespread outage may leave us without power for 18-36 hours typically…. This setup lets us manage decently through that by itself. Aquarium filters can be plugged in via extension cords to basement..

 

[Phish Tank]

That’s a pretty slick setup. It seems like you are also well set up for adding solar if you were so inclined.
I have a friend that lives off grid, and has an electric car. Last summer I helped him set up a program running on a raspberry pi that monitored the voltage coming in off the panels (using a Shelly Uni voltage sensor) and controlled when his car charger would run (using an OpenEVSE charge controller). His goal was to have his car charger running only when the sun was shining brightly without having to manually walk out to the garage and turn it on.
I agree with you on ecoflow, I do grow weary of endless subscription models, especially with physical devices.

 

[Pepere]

It seems like you are also well set up for adding solar if you were so inclined.

One thought of installing it in a caddy with the wheels in the back was to increase mobility to bring it outside and hook up temp solar panels to recharge in event of an extended outage.

Alternatively I could put 6 100 watt panels on the roof, and add another inverter. The second inverter could run the fridge and freezer all of the time, and I could disconnect grid power to the boiler to run that all the time. I could have the wifi plug turn on the charger for an hour or two every night to top off the batteries in the event it was a cloudy day…

It is hard to get excited about doing so though. 6 panels would cost about a grand, not counting charge controlers, racking, wires, connectors. A second inverter is another $200.00. Easily 1,500.00.

2 inverters consume 500 watt hours a day simply maintaining the waveform whether anything is running or not. And at best they are about 90% efficient when provding power to an appliance.

Boiler, fridge, and freezer consume roughly 2-2.5 kwhr per day. Figure in an annualized basis, 2 kwhr at most. At 0.21 a kwhr, I might save $150.00 a year…. A ten year Return On Investment is not terribly enticing, esp given the fact that inverters have finite lifetimes and do infact where with usage, thoughts of water ingress from roof penetrations, wind loading on panels etc…

The economics of home solar do not entice me much.