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Who's the best large battery for off grid?

NewRuins

NewRuins

New Member
Joined
Aug 6, 2020
Messages
25
Location
Oaxaca Mexico
Is there a clear king of the large batteries?
Im tired of diy lifepo4 and shitty chinese bms and looking to spend some money.
That will handle heavy abuse/use.
Can handle Low % dod. Or at least protect itself
20khw +
Handle big peaks and valleys of usage. (I host large groups and times where there's nobody/low loads)

Panasonic? Some weird salt water battery? Server rack battery? What company is doing it right but maybe charges a premium?
Looking for recommendations for your dream battery
 
If you want to go turnkey commercial off the shelf, the new Tesla Powerwall 3 that now supports DC and AC coupling. And the new cheaper to add DC coupled expansion batteries will be out in the next few months. Keep in mind that with the PowerWall you don't need a separate inverter. It's all built in. And I don't think people realize this, you can buy PowerWalls and install them yourself.

Personally, I'm still in the pure DIY camp because I can save so much money that way. But I don't use in low quality components. I use surplus Model 3/Y battery modules and I use the Tesla slave BMS boards on the modules. I connect them to GoodWE A-ES series HV hybrid inverters. I don't think anybody makes better BMS hardware than Tesla. And I typically get 75 kwh of surplus Tesla batteries for 3 to 3.5k. And that typically includes all the penthouse electronics. I can resell that stuff and get $750 to $1k back.
 
Check out the EG4 ESS offerings, seems to be pretty much plug-n-play. I’m still awaiting final delivery of all the pieces and my supplier seems conflicted on whether or not they have ordered 1AWG wire or are picking it up today, but it seems to me that it’s a good compromise between Tesla and build your own batt solutions.
 
NewRuins said:
Is there a clear king of the large batteries?
Click to expand...
I just converted a 42 kWh DIY pack to seven Pytes V5 server rack batteries. In my mind it is the best, but I am mindful of what the Dalhi Lama said when someone asked him what was the best religion. His response, "The best religion is the one your are practicing today." In my case, I had particular features I needed which influenced my choice, closed loop communication with my SolArk, self heating since I had to put them in an external enclosure, modularity so I could expand if needed, UL listing with the SolArk so I could get a building permit and a good warranty. The price per Watthour was over three times what my DIY pack cost to build but the peace of mind was priceless.
 
jpwhit said:
If you want to go turnkey commercial off the shelf, the new Tesla Powerwall 3 that now supports DC and AC coupling. And the new cheaper to add DC coupled expansion batteries will be out in the next few months. Keep in mind that with the PowerWall you don't need a separate inverter. It's all built in. And I don't think people realize this, you can buy PowerWalls and install them yourself.

Personally, I'm still in the pure DIY camp because I can save so much money that way. But I don't use in low quality components. I use surplus Model 3/Y battery modules and I use the Tesla slave BMS boards on the modules. I connect them to GoodWE A-ES series HV hybrid inverters. I don't think anybody makes better BMS hardware than Tesla. And I typically get 75 kwh of surplus Tesla batteries for 3 to 3.5k. And that typically includes all the penthouse electronics. I can resell that stuff and get $750 to $1k back.
Click to expand...
Do you have any references for purchase? Where is your preferred vendor for surplus Model3/Y Battery modules?
 
NCislander said:
Do you have any references for purchase? Where is your preferred vendor for surplus Model3/Y Battery modules?
Click to expand...
Originally ebay, but now some of the Tesla dismantlers call me if they have something they know I may be interested in buying. I also occasionally buy wrecked Tesla's and repair them. There are a lot of businesses that buy wrecked Tesla's and break them down for parts to resell. You can make a lot of money doing that at scale if you have the infrastructure to do it. Most of the money is in body panels and a lot of the smaller parts. Actually folks have been doing this with lots of cars like BMW, Mercedes, Porsche, etc for a long time. Any car where parts tend to be expensive can be very profitable.
 
jpwhit said:
Originally ebay, but now some of the Tesla dismantlers call me if they have something they know I may be interested in buying. I also occasionally buy wrecked Tesla's and repair them. There are a lot of businesses that buy wrecked Tesla's and break them down for parts to resell. You can make a lot of money doing that at scale if you have the infrastructure to do it. Most of the money is in body panels and a lot of the smaller parts. Actually folks have been doing this with lots of cars like BMW, Mercedes, Porsche, etc for a long time. Any car where parts tend to be expensive can be very profitable.
Click to expand...
Are you the "Guy" online, previously 057 Tech? There was an online presence selling Tesla batteries not long ago. Website since no longer out there. Somewhere here in North Carolina.
 
I would do a bunch of eg4 powerwall. They are 300# each. Or, your rack battery of choice. They are all plug and play, especially in voltage mode.
 
NCislander said:
Are you the "Guy" online, previously 057 Tech? There was an online presence selling Tesla batteries not long ago. Website since no longer out there. Somewhere here in North Carolina.
Click to expand...
Nope, never been on here until a week ago. There is a Tesla dismantler in SC that I've seen try to sell some Tesla stuff for Solar. I don't sell any of this stuff, just do it for myself and a few friends and family.
 
jpwhit said:
If you want to go turnkey commercial off the shelf, the new Tesla Powerwall 3 that now supports DC and AC coupling. And the new cheaper to add DC coupled expansion batteries will be out in the next few months. Keep in mind that with the PowerWall you don't need a separate inverter. It's all built in. And I don't think people realize this, you can buy PowerWalls and install them yourself.

Personally, I'm still in the pure DIY camp because I can save so much money that way. But I don't use in low quality components. I use surplus Model 3/Y battery modules and I use the Tesla slave BMS boards on the modules. I connect them to GoodWE A-ES series HV hybrid inverters. I don't think anybody makes better BMS hardware than Tesla. And I typically get 75 kwh of surplus Tesla batteries for 3 to 3.5k. And that typically includes all the penthouse electronics. I can resell that stuff and get $750 to $1k back.
Click to expand...
Just read the marketing material for the powerwall 3. That does look nice
 
DIYrich said:
If you want large scalable industrial quality:

Redflow – Sustainable Energy Storage

redflow.com redflow.com
Click to expand...
Neat, and Sol-Ark integration! C’mon EG4, get with the program!

Strange that a flow battery has a fixed capacity (10 KWHR, 26 gallons), I thought the whole point of Flow batteries was that you size the electrode stack for your power requirements and your electrolyte volume for your (KWHR) storage.

Also bizarre that the discharge duration is 4-12 hours, and gets less efficient outside that range. I’d need some weird control system to store excess summer production for winter use (to say nothing of tens of thousands of gallons of electrolyte).

Anyone know what those batteries cost?
 
wpns said:
Strange that a flow battery has a fixed capacity (10 KWHR, 26 gallons), I thought the whole point of Flow batteries was that you size the electrode stack for your power requirements and your electrolyte volume for your (KWHR) storage.
Click to expand...
Not a true flow battery. Some of the reaction requires depositing onto the electrode, not a catalyst reaction.
 
NewRuins said:
Damm cant seam to buy the powerwall without their installers. I need to freight forward ot to Mexico
Click to expand...
I just checked and it seems they removed the option to order the Powerwall without installation from the website. But I've read people have been able to call them and order w/o installation if they told them an approved installer would install it.
 
So apparently the power wall 3 will soon have a DC coupled battery expansion option, for a $1000 less than the full fat units with inverter/sccs etc. Increasing storage, same output.
 
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