Off grid equipment questions

#1
Batteries:
I’m going to purchase 24v Forklift batteries.
Question:
Should I buy (1) 14-kWh battery or (2) 7-kWh batteries?

INVERTER:
I’m looking at Pure Sine Wave Inverters.
Question:
Should I purchase a 4000w - 8000w peak, or a 6000w - 18000w peak inverter using the above battery pack(s)?

I’m currently using a Firman 10,000/8000 portable generator which I will be using to recharge the batteries until I get a few solar panels. Then the generator will be used more as a backup when the solar panels are unable to charge during cloudy, snowy and rainy days.
It’s a Duel Fuel generator that I have running off a small propane bottle at the moment. A 500 gal propane tank is in the works to be installed and connect to this generator.

I’m currently fighting Disabilty and have no income. I have a small amount of money from a 401KNew. What I’m doing is eliminating the electric company (who shut me off) and the water company. I found an old shallow well that I’m going to redo for basic water needs. This includes an aerator and a filter system, plus a propane powered tankless water heater.

Anything I’m doing incorrectly or that I might consider doing differently, please let me know.
 

HandLoad

Magnificat
Brass Subscriber
#2
Inverter choice should be driven by Your needs.

I would choose Two Batteries, and run them in Series (so, @48VDC), to reduce system's Current losses. Smaller conductors are cheaper to buy and replace.

BTW - fun avatar!

[EDIT]: Welcome to the Site! Introduce Yourself when You are comfortable!
 

Red dog

Well-known member
#3
If you are not already tied to a 24V system I would go as HL suggested and go 48V.

As far as the batteries go otherwise, weight might be the determining factor as to go with one or two. Originally I was thinking of going with a single 48V forklift battery but it's 3000# weight was more than I could lift so I went with two 24V batteries that came in around 1500# apiece connected in series for my 48V system.
 
#4
If you are not already tied to a 24V system I would go as HL suggested and go 48V.

As far as the batteries go otherwise, weight might be the determining factor as to go with one or two. Originally I was thinking of going with a single 48V forklift battery but it's 3000# weight was more than I could lift so I went with two 24V batteries that came in around 1500# apiece connected in series for my 48V system.
I’m so close to ordering the battery but I haven’t figured out how I’m goin to get it out of the truck, let alone move it to the house!
I like the 2 battery setup, I’m going to price that route.
 
#5
Inverter choice should be driven by Your needs.

I would choose Two Batteries, and run them in Series (so, @48VDC), to reduce system's Current losses. Smaller conductors are cheaper to buy and replace.

BTW - fun avatar!

[EDIT]: Welcome to the Site! Introduce Yourself when You are comfortable!
2 battery setup will also help with the weight issue.
Here’s the inverter:
4000W Peak 12000W Pure Sine Wave Split Phase Power Inverter With Charger 40A,DC 48V AC Output 120V 240V Converter LCD Remote Control
Item ID #:SG-4000C

The avatar is from a small Laser business I had a while back.

Thanks! I’ll do the introduction thing as soon as things settle down here. It’s been a challenge keeping the lights, fridge and TV on.
 

HandLoad

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Brass Subscriber
#6
4KW Is a pretty big energy budget! I am ON GRID, and My nearly 5000 SqFt home averages just over 2KW running load. Biggest single Draw is She Who Must Be Obeyed's Hairdryer, at 1875 Watts. Starting load spike biggest draw is the Heater, with a 1/2 Horsepower Circ fan. Draws over 2KW for a Half-Second or so.

Those figures were before I converted nearly all Lighting to LED.
 
#8
I checked into a 48v setup. The inverter was easy, however, the batteries jump in price quite a bit going from 24-48v.
If you do (2) 24v, you lose quite a bit of kWh compared to a singe 48v.
 
#9
4KW Is a pretty big energy budget! I am ON GRID, and My nearly 5000 SqFt home averages just over 2KW running load. Biggest single Draw is She Who Must Be Obeyed's Hairdryer, at 1875 Watts. Starting load spike biggest draw is the Heater, with a 1/2 Horsepower Circ fan. Draws over 2KW for a Half-Second or so.

Those figures were before I converted nearly all Lighting to LED.
Thanks for the info, I had no idea on what size inverter to get, I figured it was better to be a bit over what I need, but it turns out, I was WAY overboard and can scale the inverter down saving a lot of money!
 

HandLoad

Magnificat
Brass Subscriber
#10
Do a load survey before choosing! If You have a Well, you need a great big hairy-knuckled monster jnverter. If You have Electric cooktop, and/ or Oven(s) you will need a more capable Inverter. Same with electric heat.
 
#11
Note, though, that I have Nat Gas House heat, Water Heating, Cooking Appliances and Clothes Dryer. I do not have a Well. Only a small A/C seldom used.
I understand, my house is currently being converted to propane, so those huge load devices, dryer, stove and water heater will be totally eliminated. The well pump is something to add in to the mix as they are hi amp draw. My electric heat central air system doesn’t work, so I use a fan and sweat a lot.

I’m thinking about just using a A/C window unit in the center of the house. I heat with firewood
 
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#12
I understand, my house is currently being converted to propane, so those huge load devices, dryer, stove and water heater will be totally eliminated. The well pump is something to add in to the mix as they are hi amp draw. I central air system doesn’t work, I use a fan and sweat a lot. And it’s an electric heat central air system.

I’m thinking about just using a A/C window unit in the center of the house. I heat with firewood
And every light inside and out is a LED. I’m a bit of a geek, and have been using LEDS for decades. I even have touch screen like wall light switches, a few have remotes.
 

The Branch Manager

Winter is coming. Forever.
Gold Subscriber
#14
I keep in mind I don't have solar and don't know jackshit about nothing, but it seems to me that a person on a budget wood choose six or eight small cells instead of one great big cell. If the big cell goes out you're stuck with the entire cost of replacing it. The small cells can be replaced individually at a much much lower cost. It may cost a little bit more up front but I would think going forward on a fixed income that's how I roll. Again don't listen to anything I say or make any financial decisions based upon my rant
 

Red dog

Well-known member
#16
Problem with using something like golf cart batteries is their short life to cost ratio. Typically golf cart batteries have a lifespan of around 5 years in a full time solar application, a large forklift battery with comparable KWH output costs about the same as the multiple batteries but have shown a typical 20+ year lifespan, so more bang for your buck. And if you did have a cell go bad in a forklift battery it can be replaced.

I keep in mind I don't have solar and don't know jackshit about nothing, but it seems to me that a person on a budget wood choose six or eight small cells instead of one great big cell. If the big cell goes out you're stuck with the entire cost of replacing it. The small cells can be replaced individually at a much much lower cost. It may cost a little bit more up front but I would think going forward on a fixed income that's how I roll. Again don't listen to anything I say or make any financial decisions based upon my rant
 

The Branch Manager

Winter is coming. Forever.
Gold Subscriber
#17
Problem with using something like golf cart batteries is their short life to cost ratio. Typically golf cart batteries have a lifespan of around 5 years in a full time solar application, a large forklift battery with comparable KWH output costs about the same as the multiple batteries but have shown a typical 20+ year lifespan, so more bang for your buck. And if you did have a cell go bad in a forklift battery it can be replaced.
Told you not to listen to me.