Seeking Advice on DIY Battery Build (15-16kWh) for Upcoming PV System

fisherb777

Hi everyone,

I’ve been browsing the forum for a while and am planning to purchase components for a DIY battery build (15-16kWh) for my upcoming PV system. I’d really appreciate any advice you can share.

My setup will consist of 20 x 455W panels (10 facing South, 10 facing North). Here are my key questions:

1. Hybrid Inverter Recommendations
   Which models would you recommend for seamless integration with a DIY battery (with JK BMS)? I’m considering Deye/Sunsynk, but I’m open to suggestions.
   Note: I don’t plan to apply for NC7, so inverter power and battery charge/discharge rates will be limited.
2. Battery Enclosure Options
   For the battery box/enclosure, what’s worth considering on the market right now? Seplos, Yixiang, Luyuan? Also, which suppliers can deliver to Ireland relatively quickly (don't want to wait 2-3 months, time is money ;) )?
3. Attic Installation & Weight Concerns
   I plan to install the entire system in my attic. The battery alone will weigh around 120kg—should I reinforce the floor, or is this load manageable as-is?
4. Increasing Charging Speed
   To maximize charging during off-peak hours (3-4h window with cheap rates), could I add a 3kW rectifier/charger to speed up the process?
5. Discharge Rate Limitations
   I understand my inverter will limit discharge to 5kW/h. Is there any way to increase this discharge rate?

irishchris

To answer your second question I recently ordered the yixiang battery box and took about a week from their European warehouse. Top quality box and easy to deal with

fred funk }{

https://www.boards.ie/discussion/comment/123335434#Comment_123335434

Same here. Arrived about a week later. Just gotta make sure it's coming from their EU warehouse.

Abromavich

https://www.boards.ie/discussion/comment/123335434#Comment_123335434

Hey Chris - Im about to order a few of these. Do you have a link to the stock you purchased?

...Ghost...

1. Solis hybrid is fine if you're staying at NC6 with single battery.
2. I use Seplos. I like them and have built 3. Have videos posted here too for the DIY build.
3. If you mus install in attic, be sure to spread the load of the battery. Heat can be a real issue in the attic too.
4. I'm in the middle of doing this right now. Hope to finish it tomorrow and will post video of it soon after.
5. I'm not aware of how to discharge more quickly than the inverter unless you manage to get 2 hybrids playing friendly and then you'd technically need an NC7.

irishchris

https://www.boards.ie/discussion/comment/123335954#Comment_123335954

https://www.alibaba.com/x/x14ftuL?ck=pdp

You can then order through the send request button

Abromavich

Thanks Chris - ordered 3 of their boxes today and a trolley. They said EU stock is arriving in from China and should ship from EU warehouse by 20th Apr.

irishchris

https://www.boards.ie/discussion/comment/123342685#Comment_123342685

Nice one, all the best with the builds bud 👍

concubar

Roughly how much do they work out landed?

Are most getting their batteries from nkon ?

Was going to go fogstar but this looks better?

Thanks in advance 🙂

positron

Following this thread, as I wouldn't mind doing this myself.

On this:
Attic Installation & Weight Concerns
I plan to install the entire system in my attic. The battery alone will weigh around 120kg—should I reinforce the floor, or is this load manageable as-is?

Wouldn't it be better to hang it off the wall with some wall brackets? Also what do people do to get this to the attic, I am guessing assemble it in the attic at it's final location? My back aches just thinking about lifting all that up the stairs.

fisherb777

https://www.boards.ie/discussion/comment/123343892#Comment_123343892

Yea, that's a good idea, I probably hang it on the wall.
It will be assembled in the attic, I need to come up with some sort of a mechanical ventilation system first.
It can be really hot there in the summer time.

Do you know what's the highest safe temp for the batteries ?

fisherb777

https://www.boards.ie/discussion/comment/123342538#Comment_123342538

Thanks for you input Ghost.

1. I will stick with the NC6. I see that more people are recommending deye/sunsynk, but it's actually easier to get Solis inverters in IE.
2. Have to check out your videos, is there any possibility to hang seplos battery on the wall?

Do you know anyone using seplos batteries with DEye inverters?

...Ghost...

https://www.boards.ie/discussion/comment/123371347#Comment_123371347

I have the Solis and I like it. Does the job nicely.

I think @SD_DRACULA might have experience with DEYE inverters. I'm almost sure he sold an 8kW one last year, but I could be mistaken.

edit: It was a Sunsynk, but maye now he has a DEYE.

Yeah, you can mount a Seplos battery to the wall, but needs to be in a cabinet frame. This is what I did.

https://youtu.be/hx2GTp52DGU?si=L4RJZG7DXSSAmDuh

mjatkey

Guys, any body had any dealings with this crowd good or bad.

Value wise looks very good €1500 delivered

Battery Pack 51.2V Power Bank Battery Kits Lifepo4 3.0 Version With Active Balancer Built In BMS 280AH – Deligreencs

Looking at increasing the storage in the apartment with the addition of a second Seplos.

Just wondering if they are legit?

olympicweights

Price looks good and grade A cells

mjatkey

https://www.boards.ie/discussion/comment/123474435#Comment_123474435

But is it too good? I've pinged them to see how long delivery would be from placing order but they've not come back yet.

olympicweights

You left something behind. Hi dear . I saw that you left some products in your cart. Did you have any questions or experience any problems? Feel free to reply to this email and I will get back to you. Also I'd like to give you a $10 coupon, please enjoy it. Discount code: 10OFF Free Shipping& Free Tax - Seplos 3.0 Battery Pack 51.2V Power Bank Lifepo4 With Active Balancer Built In BMS $577.00 - $1,708.00 I received the above email, I was checking shipping cost so it must have picked up my email address from autofill details? You'd like to hear feedback from someone on here