Finally going off grid, need a bunch of help

So, fully loaded, this bank Will power the inverter about 2 hours.

Fine for a small bank, but likely need to double up soon depending on usage loads.

I use a 60W halogen bulb to bleed my inverter caps... works fine.

Hedges said:

Oh, "14 of them" meaning 14 of these 48V batteries in parallel, 14 x 30A = 420A available, and 10kWh or so?

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Yes they are rated at 748 watts. So 14 * 748 = 10,472 watts, yes 10kWh.
But if you look at the test results they are testing over 770 watts.

The LV5048 manual states the battery cut off is 40v. Unless that is adjustable, I'll be only using the top end of the batteries.

Using my kilowatt meter, where I am staying at I use about 200-300 watts continuously per hour. That includes my lights, deep learning desktop, chargers, and starlink. If I stayed under that, I'd have 52 hours of run time.

It would be nice to use some high power stuff, I never considered it. If I had more money I would
* Nvidia 2080ti, 16 core amd deep learning system... about 700 watts. Was going to sell it for a profit.
* Toaster oven. I think 1500 watts, 40 minutes to cook my chicken breast
* Microwave, I think 1200 watts. 15 minutes to cook my vegetables
* Air conditioner that tested at 450 watts, not sure what the surge inrush is.
* One of those 'portable' ice making machines, it claims 290 but I remember it tested at 350 watts. This I keep on all day when I was at the farm

However, I was going to ditch all of the above and live a simpler life. But I will test it while I am prototyping this setup.
Consider that the LV5048 will also provide power from the solar when it is available, if I am strategic about when I use things I could be fine.

One day when I have a half a dozen daughters running hair driers all day, and I'm running 4x 3090 bitcoin miners, I'll upgrade my system But it is just me this should be fine

...
Based on the feedback (Thanks) I think I am going to go with:

187-Series Circuit Breaker - Surface Mount 200A​

7149


$80

offgriddave said:

Solar
- I only have 4x 250 watt 37v panels right now, but I want to order a pallet (27-29) for 350+ or 400w panels. (Any suggestion)? I want 10kwh. The property gets a lot of fog so I need to build it out four times the capacity I need. The panels aren't compatible with the Giandel because of the voltage, but somehow they work. Huge loss in effiency.

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Many of us have bought from SanTan Solar. They have used and some new. Prices range from $0.12 to $0.50/kW. Some have had UL stickers removed.

I like to have excess PV, and both morning and evening orientation for more level production. I try to draw from battery as little as possible, just run things of AC as it is produced. My system is grid-backup, so not usually depending on it.

offgriddave said:

* Air conditioner that tested at 450 watts, not sure what the surge inrush is.

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I measured the surge for you. 4x nameplate. Running under mild temperature conditions, power draw was 1/2 of nameplate.


You're talking about cooking with electricity. How do you plan to heat water? Heat the house?
I think you could have an electric water heater to be enabled when batteries are full, so using surplus PV.

Hedges said:

I measured the surge for you. 4x nameplate. Running under mild temperature conditions, power draw was 1/2 of nameplate.

Is 600w enough

I plan on putting 600w of solar panels on the roof of a small camper. The Panels will be able to tilt so I can get as much power as I can. My main use is to run a 5000 BTU AC tha draws 450w in the summer and a 500w space heater in the winter & a few little items like phones, tablets and led...

diysolarforum.com

You're talking about cooking with electricity. How do you plan to heat water? Heat the house?
I think you could have an electric water heater to be enabled when batteries are full, so using surplus PV.

Click to expand...

I have a propane on demand camp water heater, new in box. I've used these before when I had my farm.

For heating I have a Liberator Rocket Heater, paid $1800. It is still new in the box unopened
Here's a picture



The property I am trying to buy is fully timbered and I just finished building a 26"x16.5ft capable wood saw mill for lumber.

My plan is to buy a RV with a damaged roof or side at auction, build a pole barn car port around it. Sawzall one side of the RV and timber frame a 200-300ft tiny house with an open floor plan. Use the propane refrigerator and range of the RV. This is going to be a crazy year.

I was just speculating about using the electronics for everything, but the plan is minimal use. But I'm basically in the ball park!

Propane will get you started.
Once you're settled in, consider a conventional electric refrigerator, and power it only when the sun is up. (Or 24 hours a day if it turns out battery lasts the night.)
Use an electric water heater for pre-heat, so propane only needed if not warm enough. But does the on-demand one adjust its power?

Maybe a wood fireplace can make much of your heat.

I was going to do something similar before. I built an 8x20' stick-frame room intending to dock my 18' RV to it. They are still on separate pads on the lot, so room is storage and I used the trailer for a time. Very small spring filled a 50 gallon drum up the hill, providing gravity feed.

I never did fell or mill anything. Some of those trees are 6' diameter now.
I spent all my time trying to keep tractors running long enough to cut a road. Mostly mechanical issues, old farm Cats.

Yes, there is a spring about 100 ft height above, I think. And then there's also a creek. I have about 10 IBC totes and one of those Intex pools you see at walmart.

If I get the property, I am going to try and place the homesite where the water can flow from my irrigation pipes to get 40-60 feet drop. Glad I kept all of my irrigation pipe fittings, poly, PVC from my farm when I sold it!

The rocket heater, which burns wood, would more than enough heat the place. I will be frying inside. It also never gets under 40f except for one week a year.

The property is so overgrown right now, you can't even get into it. There's a road in the middle but it so overgrown it took me hours just to get a few hundred feet with my chainsaw. 40-50 year old trees growing in the road. I am thinking I need to rent or buy an excavator. I have a Case 530CK backhoe and a ford tractor, but I might try and sell them and just get a mini excavator with a thumb. Before I do that I'll rent one for a week and try it out. I have never used one before.

When Li-ion cells get tired, they will sometimes start to heat up, more than normal. Also, under normal use a battery will have some heat. If it were me, I would avoid putting those packs right together. I would arrange them in such a way that I could feel the sides of them to check for unexpected heat. Routine checking to make sure you don't have a cell that is turning into a heat source is a good ideal.

offgriddave said:

Yes I had some serious problems with his setup, using zinc plated bus bars and no safety equipment. He gets a lot of views on youtube and is pretty trendy.

I bought the PowerStrip 160A-SB120 Anderson connector version with xt60. I will be running 15 amps through the xt60. On this version it has four layers of copper, it claims 2oz. I figured that's enough,

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Thank you for the reality check here... I've been looking at Jehu's stuff for a while before finding Will's YT channel. I think I will stick with Will's recommendations. I'm looking hard at the 48V BDGR unit from BigBattery.com after seeing Will's review of it, but $268 shipping for a $500-600 battery is hard to stomach. They offer free shipping for 5 or more units. While I DO own an electric golf cart with brand-new lead acid batteries that I could replace with 2-3 of these units, it's still not worth it to me. Any other tips on saving shipping costs? Maybe picking up cells in the local Seattle area and DIY?

hoeveler said:

Thank you for the reality check here... I've been looking at Jehu's stuff for a while before finding Will's YT channel. I think I will stick with Will's recommendations. I'm looking hard at the 48V BDGR unit from BigBattery.com after seeing Will's review of it, but $268 shipping for a $500-600 battery is hard to stomach. They offer free shipping for 5 or more units. While I DO own an electric golf cart with brand-new lead acid batteries that I could replace with 2-3 of these units, it's still not worth it to me. Any other tips on saving shipping costs? Maybe picking up cells in the local Seattle area and DIY?

Click to expand...

I bought my 48v batteries from Battery Hookup

These ones:


I got 16 total. One as broken for parts or fixed. The rest were 100%. I will use one for an actual e-bike that I haven't built yet and 14 for 10kwh off grid. I pulled the trigger because they already had fuses, integrated BMS, and Battery Hookup tests them with a ZKE programmable tester. They also answer emails, I asked them where I could ask questions -they pointed me here; I had already created an account last year.

I haven't opened the broken ebike battery yet, but I want to see if the BMS has a temperature sensor because of DThames's comment above

offgriddave said:

I bought my 48v batteries from Battery Hookup

These ones:

Greenway FULLY TESTED 48v 15.6ah 748.8wh w/ BMS

Shipping only available to the United States and Canada. Here are 48v battery packs with a 30a BMS and 40a inline fuse. These batteries come fully tested with a printout including capacity and curve chart (sample shown in the 2nd photo). The D-CC represents the discharge capacity reading. Each...

batteryhookup.com

I got 16 total. One as broken for parts or fixed. The rest were 100%. I will use one for an actual e-bike that I haven't built yet and 14 for 10kwh off grid. I pulled the trigger because they already had fuses, integrated BMS, and Battery Hookup tests them with a ZKE programmable tester. They also answer emails, I asked them where I could ask questions -they pointed me here; I had already created an account last year.

I haven't opened the broken ebike battery yet, but I want to see if the BMS has a temperature sensor because of DThames's comment above

Click to expand...

Thanks for the Hookup, offgriddave!

hoeveler said:

Thanks for the Hookup, offgriddave!

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If I had to re-do it I'd go with Lithium Phosphate, the neighbor went that direction.
I went with Lithium Ion because they already were built with a BMS. Another comment on the first page mentions the bad part about going with 18650, is welding them together and testing them. Huge amount of work. Well I bought them prebuilt. With Lithium Phosphate you would need to bolt them together and find a BMS. I have limited knowledge into this, hoping after this project I will have enough knowledge to figure out the BMS. Battery hookup does have Lithium Phosphate and you should check their page a few times a day it is always changing.

Parts are starting to show up
Edit: For my battery input in the LV5048
I laid them out in the box, as a suggestion, to install
There's another picture with the fuse removed, but I didn't upload it.

Fuse + Breaker or just Breaker?
How did I do?

The main wiires are 8 awg, with no voltage loss for 2 feet. They are walmart jumper cables.

@Hedges, unfortunately I did not go with the 1-2-switch just regular breaker + fuse.

Just an update

-San Tan Solar accidentally sent the wrong panels. Instead of the Jinko 385w, I got 20x $35 240W Santan chinese specials with bad vinyl. I called and __they did the right thing__ and apparently next Tuesday or Wednesday I will pick up my panels.

- Battery Hookup screwed up and never sent a big order of 3500ma 3c discharge 18650 I had budgeted for my dewalt packs and backup solar system. I got a full refund and free shipping, but note... the order was made in February and it is May. I made a replacement order and got free shipping but instead of 3500mah I could only get 2200mah. But they are 2c discharge and will work. He has not shipped my replacement yet, fingers crossed. I still have the 14x 48v 1500w ebike batteries.

- I still have not confirmed the purchase of the land. I fired the title company due to incompetence, and went with another one. The incompetent title company tired to contact my new one and screw up the deal, but my new title company is awesome and is going the extra mile.

- I have most of the parts ready as of today from various orders on ebay, amazon, and random marine electrical parts. I will update as I go. I am currently building the backup solar setup and waiting for the Jinko 385w.

- There's a 200lb+ cougar, and cougar den as you walk in to this place. Not sure what to do about this. The roar sounds like a diesel engine in the distance. I just kept walking, but eventually I'll have to deal with this. Hopefully I can rent an excavator with a cab LOL

Having a cougar sounds like a privilege. Hopefully you can learn to just give each other respectful distance.
They're supposed to be intelligent, and curious about people. Not a threat at least to adults, unless defending their cubs or rabid. Even with cubs, there's video of one making sure a guy moves away.

If not a 2-position switch, you can set up a momentary switch and resistor for precharge as described elsewhere on the forum.

Double check polarity with a meter before connecting things or closing a switch. That should help avoid mistakes connecting batteries together, or panels together, or to inverter. One guy said a PV string was only delivering 2V to the inverter. That was because it had a reverse-polarity diode to protect it. Not all do, and battery connection doesn't.

@Hedges
Has anyone measured the "in-rush" for charging the capacitors for a hybrid inverter? Could I hook up a temporary circuit? How often do I need to "charge" my hybrid inverter's capacitors?

Regarding the cougar, when I visited the property I heard a grawl, stopped, and then I just kept walking. At the time I couldn't figure it out. I thought it was a diesel engine coming down the hill having issues (thats why I knew it was a big cat) but when I walked another 20-30ft it got quieter. When I walked back to go home, I heard it again. Then I knew it wasn't a truck. I am in no way a hunter of big game "just for fun". For meat, yes-- I do hunt. And I pack heat. I had problems with black bear at my previous farm. The problem with cougars is they don't back down -- so there is no point firing a warning shot. And on top of that this cougar is setup about 35 feet from the year round spring (obviously hunting other critters getting a drink). I am hoping to do what you are suggesting, just keep on doing what I am doing and ignore him/her for now. Still haven't closed on the property yet, but if I get it that is plan.

My sister said she was walking her Shepherd pup above Stanford when it froze. There was a cougar on a branch above the trail, and people passing under unaware. I've never encountered one, but a few other interesting critters on my mountain property.

You only need to precharge capacitors before closing switch or breaker to battery. Lithium batteries are about 1/5th the internal resistance of lead-acid, so much higher surge current. People here report welding relays, and I think blowing fuses. My inverters have internal breaker so not as easy to bypass, but I'm using AGM. I don't have a precharge. Wouldn't take much resistance to significantly reduce the current. Some people use a high wattage resistor. I think a light bulb might work. or a length of wire.

Value of capacitors will vary between inverters. It sounds like you're using a different battery from most people, so don't know how it performs. I would assume zero resistance and consider inverter standby draw, selecting a resistor or length of wire that would only drop 1% or so of battery voltage while supplying standby current. That way capacitors get charged 99% of the way. (Instead of a 10 second charge that never gets above 90% of battery, leaving 10% to still burn the main switch.) One idea I had was a length of phone/LAN wire. It would probably charge in milliseconds, then you close main switch.

Hedges said:

My sister said she was walking her Shepherd pup above Stanford when it froze. There was a cougar on a branch above the trail, and people passing under unaware. I've never encountered one, but a few other interesting critters on my mountain property.

You only need to precharge capacitors before closing switch or breaker to battery. Lithium batteries are about 1/5th the internal resistance of lead-acid, so much higher surge current. People here report welding relays, and I think blowing fuses. My inverters have internal breaker so not as easy to bypass, but I'm using AGM. I don't have a precharge. Wouldn't take much resistance to significantly reduce the current. Some people use a high wattage resistor. I think a light bulb might work. or a length of wire.

Value of capacitors will vary between inverters. It sounds like you're using a different battery from most people, so don't know how it performs. I would assume zero resistance and consider inverter standby draw, selecting a resistor or length of wire that would only drop 1% or so of battery voltage while supplying standby current. That way capacitors get charged 99% of the way. (Instead of a 10 second charge that never gets above 90% of battery, leaving 10% to still burn the main switch.) One idea I had was a length of phone/LAN wire. It would probably charge in milliseconds, then you close main switch.

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Hi OffGridDave,
I to am building a system using the greenway battery packs. I have 20 configured in groups of 5 and will be running a GrowWatt inverter. I will add some picture shortly. The batteries are in a great box, so my intent was to keep everything as reusable. Lots of zip ties and portability.
Best regards,
T-486