DIY portable generator ideas and opinions

[oldmaninsaline]

What inverter did you use in there?

I could have gone with a smaller case but wanted to leave room for upgrades. Right now I have a WZRELB 600 watt pure sine inverter (2 years old) in it. Hard on/off switch, not the soft kind so I can kill power to it through the relay. The reason is that it's all the wattage I need right now. 5.64 watts on standby, 10 amps from the batteries at my highest load. I replaced the 40 amp fuses in the inverter with 20 amp for CYA. What I did when mounting it is remove the cover (heat dissipation), bend the mounting tabs 90 degrees to mount it in the case. Then I tapped into the AC out and ran that to the AC outlets in the case, using UL outdoor rated outlets. I used the ground in the inverter and used the AC outlet screws to connect the cables (10 gauge, THHN) per NEC. Hopefully I'll feel like upgrading to a 1000 watt pure sine with terminals to allow for earth grounding.

 

[HarryN]

It won't be stored in a garage. I will keep it in the house. Then I will test some loads to see what I end up with. During a power outage I have 2 full frigerators full of meat, cheese and eggs.

Systems that have a small battery pack can be used if there is a LOT of charging capacity. That way they will still work even when it is overcast as the charging can be made up fairly quickly. To support 2 freezers like that in hot weather perhaps put 800 watts on the morning side of the house and another 800 watts on the late afternoon side.

If you are willing to sometimes run a generator for 1 -2 hours, this can also really help.

 

[oldmaninsaline]

Systems that have a small battery pack can be used if there is a LOT of charging capacity. That way they will still work even when it is overcast as the charging can be made up fairly quickly. To support 2 freezers like that in hot weather perhaps put 800 watts on the morning side of the house and another 800 watts on the late afternoon side.

If you are willing to sometimes run a generator for 1 -2 hours, this can also really help.

One of the things I have are twenty 10 pound freezer packs I keep in the deep freeze. That and my 6 coolers. They'll keep the food for 5 days or so in the coolers without having to run the genny at all.

 

[LBART]

You do want some series panels fwiw

How much solar I recommend isn’t answerable without knowing what you intend to power and for how long.

So you need enough batteries for ‘at least’ 36 hours to go one day and two nights with overcast. Minimum.

Go into ‘resources’ and do a power audit on your essential loads… once you know the watthours required then the panels and batteries can be sized.

On my current 800W (~3000W total panels I could connect quickly) I get by with the fridge, coffeemaker, furnace fan, charging devices, etc etc. but most people would be unable to function as well as I do.
Why 3kWh total? Because that might make 1.5kWh on overcast winter days, and be WAY overpaneled for 8mos.+ of the year.

I could wildhat guess at your needs but that’s like randomly buying stocks hoping for a windfall.

The only devices I really need are the 2 refrigerators. In the door the new one says 1.5a and the old one says 10a. So that should be 180w and 1200w. I don't believe in reality they are that far apart. On the last day of the power outage I used a 2000w gas generator to power them and charge the cell phones for 10 hours till the power came back. Since a lot is frozen it wasn't too bad.

My plan is a portable unit so the solar would not be out all the time. I can't put solar on this house there is a big tree covering too much of the roof and it is the neighbor's tree so it won't come down. He may agree only if I pay for the removal which is not my desire. The system I described could also be charged with grid power so it would have fully charged batteries in the event needed. Bring out the solar to add charge as needed.

 

[LBART]

Systems that have a small battery pack can be used if there is a LOT of charging capacity. That way they will still work even when it is overcast as the charging can be made up fairly quickly. To support 2 freezers like that in hot weather perhaps put 800 watts on the morning side of the house and another 800 watts on the late afternoon side.

If you are willing to sometimes run a generator for 1 -2 hours, this can also really help.

I only have one good spot in the yard so turning them a bit would suffice. No generator. If going the generator route I wouldn't need the solar. Solar is preferred by me and the learning for a future project is my main desire.

 

[LBART]

I could have gone with a smaller case but wanted to leave room for upgrades. Right now I have a WZRELB 600 watt pure sine inverter (2 years old) in it. Hard on/off switch, not the soft kind so I can kill power to it through the relay. The reason is that it's all the wattage I need right now. 5.64 watts on standby, 10 amps from the batteries at my highest load. I replaced the 40 amp fuses in the inverter with 20 amp for CYA. What I did when mounting it is remove the cover (heat dissipation), bend the mounting tabs 90 degrees to mount it in the case. Then I tapped into the AC out and ran that to the AC outlets in the case, using UL outdoor rated outlets. I used the ground in the inverter and used the AC outlet screws to connect the cables (10 gauge, THHN) per NEC. Hopefully I'll feel like upgrading to a 1000 watt pure sine with terminals to allow for earth grounding.


View attachment 139841

Something smaller like that was my original plan but as I dug down the rabbit hole my plans expanded. The best part is in my planning I can bounce ideas and get recommendations before spending the cash. I feel I am getting good advice.

 

[12VoltInstalls]

only devices I really need are the 2 refrigerators

I would put a wattmeter on them and confirm.

you need enough batteries for ‘at least’ 36 hours to go one day and two nights with overcast. Minimum.

Go into ‘resources’ and do a power audit on your essential loads… once you know the watthours required then the panels and batteries can be sized

I could wildhat guess on how much battery ~9kWh and then probs a 2000W pure sine inverter but I’m not confident without knowing the starting watts and running watts. 10A sounds like a lot! That might be ‘max’ on defrost cycle? Who knows?

That’s why doing a basic audit is useful: you gotta know the details. I’m usually comfortable wildhat guessing with small systems but I am not comfortable guessing here because it’s more like gambling without data than a calculated risk of being wrong. Or right.

 

[oldmaninsaline]

Something smaller like that was my original plan but as I dug down the rabbit hole my plans expanded. The best part is in my planning I can bounce ideas and get recommendations before spending the cash. I feel I am getting good advice.

Hey, I went with the Seahorse case simply because I could afford it. There are plenty of other types of cases you can use that cost a lot less.

In my case, I've got 22 years doing off grid projects and 45 years in mechanical and digital repair, I'm just new to Lifepo4. I was on the 7th generation of my system before I decided I'm too old to move 100 pound batteries between the cabin and condo so I sort of forced myself into it.

 

[LBART]

I would put a wattmeter on them and confirm.

I could wildhat guess on how much battery ~9kWh and then probs a 2000W pure sine inverter but I’m not confident without knowing the starting watts and running watts. 10A sounds like a lot! That might be ‘max’ on defrost cycle? Who knows?

That’s why doing a basic audit is useful: you gotta know the details. I’m usually comfortable wildhat guessing with small systems but I am not comfortable guessing here because it’s more like gambling without data than a calculated risk of being wrong. Or right.

Makes total sense to me. I need to get a Kill-a-watt and look closer. In 6 years in this house power went out twice once for 19 hrs and 44 hr the most recent time. The first time I only had one fridge so it wasn't that bad, a few bags of ice and it was fine.

I do want to tinker into the solar realm so that is another guiding force. In a few more years I want to retire and live off grid so my plans are to learn as I go.

 

[LBART]

Hey, I went with the Seahorse case simply because I could afford it. There are plenty of other types of cases you can use that cost a lot less.

In my case, I've got 22 years doing off grid projects and 45 years in mechanical and digital repair, I'm just new to Lifepo4. I was on the 7th generation of my system before I decided I'm too old to move 100 pound batteries between the cabin and condo so I sort of forced myself into it.

I really like the smaller case ideas. I saw several videos on them. I guess my tastes get more expensive and bigger as I research further. I am a rookie in this space but enjoying the learning aspect.

 

[tim0shel]

I am working on a Seahorse SE540 now that will house 4 eve 280ah batteries. This will be an Aux battery I can double my power to my main Power Generator that recently I redone along with changing the EVE batteries to CATL 280ah.
This Seahorse seems to fit these cells perfectly with 2.5" ish of extra room to the lid. I may try fitting a inverter in it but I have victron 75/15 going in with USB, powerpole PP45's, SB175 and two SB50 connections. Will be running the JK BMS on both.

 

[LBART]

I am working on a Seahorse SE540 now that will house 4 eve 280ah batteries. This will be an Aux battery I can double my power to my main Power Generator that recently I redone along with changing the EVE batteries to CATL 280ah.
This Seahorse seems to fit these cells perfectly with 2.5" ish of extra room to the lid. I may try fitting a inverter in it but I have victron 75/15 going in with USB, powerpole PP45's, SB175 and two SB50 connections. Will be running the JK BMS on both.

I looked this up and if I am finding the right stuff this is build your own battery from eve cells? The case looks good but I am leaning towards a completed battery.

 

[tim0shel]

I looked this up and if I am finding the right stuff this is build your own battery from eve cells? The case looks good but I am leaning towards a completed battery.

Yes correct I built my own batteries from the cells and JK BMS. Plenty of cases out there the best thing would be for you to decide purchase your battery then use those measurements for the battery to find a case.

 

[TorC]

Building a battery isn't that much harder, aside from generally having to figure out your own case layout. Plus side is you get to decide exactly what layout of cells works the best for the case you can buy/make and where you want it to go.

I briefly looked at some of the pre-made batteries, but I would need something supported right near me or I'm looking at a floor of $250 each way to ship lithium batteries for warranty issues. That tipped the scales heavily in favour of buying cells and making my own. Having two fully assembled 16S strings and one portable 4S battery with an inverter on it, my experience is it's just a few more wires if you are comfortable with the idea of case fabrication.

 

[LBART]

Building a battery isn't that much harder, aside from generally having to figure out your own case layout. Plus side is you get to decide exactly what layout of cells works the best for the case you can buy/make and where you want it to go.

I briefly looked at some of the pre-made batteries, but I would need something supported right near me or I'm looking at a floor of $250 each way to ship lithium batteries for warranty issues. That tipped the scales heavily in favour of buying cells and making my own. Having two fully assembled 16S strings and one portable 4S battery with an inverter on it, my experience is it's just a few more wires if you are comfortable with the idea of case fabrication.

The battery I am considering is the EG4-LL Lithium Battery (V2) | 48V 100AH | Server Rack Battery. I did see Will's review and some others so I am sure it is a good battery. I don't believe I want to deal with building a battery on my first system build. Maybe in the future it would be a good project. On this round if I tried building my own batteries and it didn't work I would be troubleshooting from a broken system with no experience. Most likely a dead end for me. Then again it could work the first time but not worth the risk to me.

 

[LBART]

Yes correct I built my own batteries from the cells and JK BMS. Plenty of cases out there the best thing would be for you to decide purchase your battery then use those measurements for the battery to find a case.

That is where I was thinking of the EG4 Enclosed Battery Rack | 3 Slot | Wheels Included. It is about a 2x2x2 cube so size wise not bad maybe a bit heavy but I would move it with a 2 wheel dolly. I don't plan to put on the included wheels.

 

[TorC]

Fair enough. I have enough general experience with electrical/electronic stuff that that wasn't much of a concern to me. When I did look a bit at the premade stuff since then, the SOK was high on my list because it can be serviced by any reasonably competent person, something I don't recall being true of the EG4.

You being on the mainland makes any needed shipping a lot easier, so you have less to worry about there.

 

[LBART]

Fair enough. I have enough general experience with electrical/electronic stuff that that wasn't much of a concern to me. When I did look a bit at the premade stuff since then, the SOK was high on my list because it can be serviced by any reasonably competent person, something I don't recall being true of the EG4.

You being on the mainland makes any needed shipping a lot easier, so you have less to worry about there.

I see the SOK 48v server rack battery is similarly priced. I might research that route a bit more before spending my money. My search came to Current Connected so I will dig through other things on their site also.

 

[tim0shel]

That is where I was thinking of the EG4 Enclosed Battery Rack | 3 Slot | Wheels Included. It is about a 2x2x2 cube so size wise not bad maybe a bit heavy but I would move it with a 2 wheel dolly. I don't plan to put on the included wheels.

I gotcha, when portable is used I am thinking more portable than the direction you are going here. My builds are for me to take off grid camping etc. with both packs I have around 7.2kw. I just need to add more solar lol.

 

[LBART]

I gotcha, when portable is used I am thinking more portable than the direction you are going here. My builds are for me to take off grid camping etc. with both packs I have around 7.2kw. I just need to add more solar lol.

That was my initial plan. But upon further research I started leaning to more power. I also need it for backup power at my home and I use 2 refrigerators. I don't want only a couple hours. It is tricky to determine the right size. In this thread I found out my solar panels needed was a bit more. I was thinking 4 200w but it seems I need between 6 and 8 200w panels. Bigger than 200w are too big to use unless I just leave them in my yard.