Biting the bullet. Doubling my battery capacity $$$$$$

[JJJJ]

Can one "Really" have enough battery power? I am finalizing my build on my third DIY pack and found myself looking at current pricing on EVE cells.

As I said in another thread, this can be addictive...

 

[Yurtdweller]

First off, my needs are microscopic. I use around 1 kwh, and no more than 2 kwh per day. I can generate 1.3 kwh per hour, and 4 kwh per day, on a good day. That being said, I recently bought 16 lifepo 280ah cells from China, planning to resell half of them. I couldn't bring myself to do that, however. So now I have a 14kwh bank. That is ten days regular use, over fifteen days conservative use. I'm totally off grid, and don't own a generator. I mention all that to say this: I loooooove having tons of storage. I rarely ever check my battery any more. I occasionally glance at my daily generation. As long as its between 1 and 2 kwh, I'm good. Will said it in one of his vids. "If you're checking your battery constantly, then your system isn't big enough." At the time I rolled my eyes, and said, uhuh, but I was running a single 1.3 kwh battery at the time, with only 800 watts of pv. Now that my system meets all my needs for generating, and drastically exceeds my storage needs except in the height of the Texas winter (Rainy season), I get it. As long as the sun comes out two days a week, I'm good. I got though two weeks of crap weather this winter, but barely. This winter has been sunnier than most. Unless you need to travel(I do) you can't really have too much battery. And, the more battery you have, the fewer true 'cycles' you'll have, therefore, you batteries Should last all that much longer. Granted, something cheaper/newer/better will always come along, but imho, you just cannot have too much battery.

 

[timselectric]

You can never have too much battery, as long as you have enough solar. And you can never have too much solar.

 

[Yurtdweller]

Don't know why it's not displaying... 32 cells.
View attachment 139152

Agree, HOWEVER, some of these server rack batteries are actually cheaper per watt, I think. I hate to admit that, but I got my cells before the server rack price dropped. I spent a year watching vids and finding a seller (https://diysolarforum.com/posts/433989/

Shenzen Luyuan Technology Co. LTD. Alibaba, Wan Amy,​

When it came time to top balance and build packs, it was easier than expected. I built 4 packs at 12v, and just ran one or two at a time, at first, but recently finally got them all assembled together into a parallel pack, in a roadie crate , and it's all good. I paid about the same price per cell, about $2600 usd total for my 14kwh order. Other than the battery cells, I probably spent another 500 bucks on the road crate, lynx power in, fuses, cables, crimps and crimpers, etc.

 

[740GLE]

How many hours last year or the year before did the grid go down requiring a >24hr battery run?

if you are in a grid down situation, you surely can go mission critical with load and avoid running everything as it wishes.

 

[timselectric]

For my house, Christmas lights are mission critical. lol

 

[740GLE]

I’ve been told hair driers are as well, luckily those only get used for 5-10, min a day.

 

[OffGridForGood]

Do you get tax credit inicentives?
On top of the sale prices?
I am a fan of DIY racks but that is me, and it is not for everyone.
Do you have an EV? could this money be better applied to one, that will also allow your existing (abundatnt) PV a place to go and offset (expensive) gasoline rather than cheap metered kWh?
Do you have TOU rates? are they super high during the daylight? do you run A/C?
Things to consider.
I vote (if this is up to a vote) more ESS is better no matter WATT. LOL.
if you have debt, pay that first, seriously, then look into the above.

 

[EastTexCowboy]

I'm in pretty much the same situation. I've been waffling between DIY batteries and another rack of the EG4 batteries. I had kinda decided to go the DIY route then wife told me she would rather have two matched racks that will probably take less floor space in the garage. Well I'm gonna tell you, I make all the decisions around here. Fortunately for her I had just changed my mind again so now she can think it was her decision.

So now I gotta pour more $$ into the project but I'm thinking that may be better than leaving it in the bank or the market. But first I need to wrap up the AC install tomorrow then next week I have a couple guys coming to help install the second set of 16 panels. Then I will definitely be ready for another rack of batteries. We're less than 4 hours away so I'm thinking I'll drive up and get them and save the freight this time.

My thinking is if I gotta do it then you should do it too!

 

[timselectric]

I'm in pretty much the same situation. I've been waffling between DIY batteries and another rack of the EG4 batteries. I had kinda decided to go the DIY route then wife told me she would rather have two matched racks that will probably take less floor space in the garage. Well I'm gonna tell you, I make all the decisions around here. Fortunately for her I had just changed my mind again so now she can think it was her decision.

So now I gotta pour more $$ into the project but I'm thinking that may be better than leaving it in the bank or the market. But first I need to wrap up the AC install tomorrow then next week I have a couple guys coming to help install the second set of 16 panels. Then I will definitely be ready for another rack of batteries. We're less than 4 hours away so I'm thinking I'll drive up and get them and save the freight this time.

My thinking is if I gotta do it then you should do it too!

One diy battery has the capacity of three server rack batteries. And only costs 2/3 of the money

 

[Shimmy]

Any thoughts on this ?

Maybe the starting point for discussion should be how much PV you generate on a cloudy day?

What I found was that if I took various multi-day moving average I would need about 250% battery to be able to eliminate all but 4 days of needing to run a generator if I didn't have grid power. Or I could double my PV and have the battery at 100% of my daily need.

You have about the same demand as me and double the PV... but I live in Hawaii. My goal is to go for a 40kWh battery and increase PV by about 30%.

 

[OffGridForGood]

For the OP: your total amount of PV seems to indicate a lot more ESS would be justified, my 7kWPV keeps 38kW ESS full (except the hit and miss Nov-Early Jan) a lot further North.
Next stage in my set up: Increase PV to 10kW, and my current DIY 304Ah battery build brings the ESS to 54kWh Total.
With good solar potential it seems ESS x 5 the PV arrary seems to work well, but in my area A/C is not a big load, which is very different from most of you guys, so I have a higher percentage of daily PV to store instead of 'instantley' consumed during hot sunny days.

 

[EastTexCowboy]

One diy battery has the capacity of three server rack batteries. And only costs 2/3 of the money

Yeah, I know. But happy wife, happy life. Also known as the rule of she does what she wants to do and I do what she wants to do and we get along just fine.

Seriously though, I'm still waffling. Gonna have to make a decision soon.

 

[Zapper77]

I want another stack of 6 EG4 LP4.

You can never have too much battery, as long as you have enough solar. And you can never have too much solar.

10 kW solar array for a 30 kWh battery?

 

[Danke]

One diy battery has the capacity of three server rack batteries. And only costs 2/3 of the money

I’d say it depends.

UL listed cost a premium.

Since I doubt DIY is UL listed, a comparison:

One can buy 10 x 100Ah Rack Batteries/with shipping from China for ~$8,800 after 30% FTC.

 

[EastTexCowboy]

One diy battery has the capacity of three server rack batteries. And only costs 2/3 of the money

Didn't you say you built one with the 304a EVE grade B from 18650Battery? There's been so much back and forth I can't remember and can't find the discussion on it.

 

[timselectric]

I want another stack of 6 EG4 LP4.

10 kW solar array for a 30 kWh battery?

Yes,
If 10kw solar can cover the daytime loads and more than replenish the nighttime battery drain.
Adding capacity just increases autonomy. (Time you can run without solar production)

 

[timselectric]

One can buy 10 x 100Ah Rack Batteries/with shipping from China for ~$8,800 after 30% FTC.

I would also doubt that those are UL listed.
But maybe, that's your point.
So, throwing out UL listing.
Your $8,800 for about 51kwh
My $8,000 for about 57kwh
And mine are delivered in 3 days.
The math still works in my favor. At least for my location. If you aren't in the US, of course it would be different.

 

[timselectric]

Didn't you say you built one with the 304a EVE grade B from 18650Battery? There's been so much back and forth I can't remember and can't find the discussion on it.

I have built two with LF280K from 18650batterystore, so far. At least 12 more in the plans. And considering another 7, because I found some more space. In a bathroom closet that is only 10ft away. lol

 

[JJJJ]

I have built two with LF280K from 18650batterystore, so far. At least 12 more in the plans. And considering another 7, because I found some more space. In a bathroom closet that is only 10ft away. lol

I am assembling third pack. Does it ever end???