Requesting some advice

getinthebag

New member
Joined
Apr 17, 2021
Messages
2
Hiya,

Can I please get some advice and tips please 😜. I would appreciate the shit out of it.

I will try to be concise..


I intend to make a battery system to run off solar panels on my grid connected house.

Some Details:
  • I'm in Australia on the 240V 50Hz grid.
  • Have lots of 18650 cells tested at around 2400mAh on average totalling approx. 1kWh currently, (easily have 3kWh once sorted).
  • Currently have approx. 4kW of existing solar install tied to the grid.
  • I have a further 2kW of new panels unused.
  • I have a spot welder and have built smaller batteries before.
  • Am a poor arse carpenter, but I'm resourceful (read: cheap).

I would like some recommendations on making a seamless standalone installation, that can rely on batteries potentially daily, separate from my current solar install for the time being and then potentially reaching the point where I can not rely on the grid so substantially (dreams hey 🤨😎).

I was wondering:
  • Is 14S reasonable?
  • Recommendations on BMS's?
    • Is a simple DALY BMS adequate?
    • Are there units that interface with certain hybrid inverters?
  • Inverter?
    • do people sometimes use a separate inverter for charging and discharging?
    • I see hybrid inverters for sale. How well or which ones interface with a DIY battery?
    • can you have two solar inverters on the same circuit anyway?
    • Can you feed an off the shelf 12Vdc -240Vac Sine wave inverters output straight into your mains (this one is more an out of interest)
  • Are people getting any sort of decent service life on Li-ions cycled daily?

I think that's all I'm pondering for the minute.

Thanks for your wisdom 🤗,

Pete.
 

Korishan

Moderator
Staff member
Joined
Jan 7, 2017
Messages
6,423
Welcome to the community. There's loads of information that has been collected here. Due to how much you are asking, I would recommend looking at HBPowerwall, DIY Tech & Repairs, and others youtube channels.
Also there are loads of threads on the above questions.

There are so many options available, and variations on setups, that it would be hard to make any recommendations of specifics.

But to start off with, I would recommend 48VDC as usually components are more efficient and cheaper overall. Plus wiring is cheaper for the higher voltage.
 

floydR

Well-known member
Joined
Aug 23, 2017
Messages
1,066
  • 14S reasonable?
  • Recommendations on BMS's?
    • Is a simple DALY BMS adequate?
    • Are there units that interface with certain hybrid inverters?
  • Inverter?
    • do people sometimes use a separate inverter for charging and discharging?
    • I see hybrid inverters for sale. How well or which ones interface with a DIY battery?

    I think that's all I'm pondering for the minute.

  • 14s is 48v in 3.6/3.7v 18650's
    JBD smart BMS, Ant smart BMS, Daly has had some problem with their SMART BMS's there non smart Bmses seem rock solid.
    There are BMS's that interface with inverters mostly higher cost BMS's with can ports/Rs485 ports, biggest problem are the many different protocols in the different interfaces (helps to be a programmer)
    Growatts , MPP, are Popular
    As Korishan stated earlier there are many threads on the above questions
    Later floyd
 

getinthebag

New member
Joined
Apr 17, 2021
Messages
2
Thanks guys,

I apologise for duplicating threads.

I will delve a little deeper into the forum 🤿.
 

floydR

Well-known member
Joined
Aug 23, 2017
Messages
1,066
No need to apologize, stuff happens just remember that search button on the upper right is your friend. Helps to use general terms then narrow the search down with more details. I still get quite a few Not found or my favorite"The search could not be completed because the search keywords were too short, too long, or too common." messages

Later floyd
 
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