Not so easy to add all your appliances, because of a few factors:

1) hours of usage may vary day to day, season to season
2) you might also change your appliances over the years
3) you might add new appliances too

As for following your bill, it is far from perfect too, as it also depends on your usage that month, but you could get, say maybe 6 backdated bills and average out the usage. To estimate the solar power, you cannot buy the exact amount as shown on your bill, as the solar panels do not charge at 100%, I would say you need to add another 25% on top of the monthly bill. And solar panels will depreciate its power over the years, so your 5kw system could be only 3kw after 10 years.

Are you planning on an off-grid system? If yes, you still need to find a big enough battery to store all this power.

This thing do balancing by dissipating extra power away. No active balancing.
Mininum cell to connect to the battery control board is 3 so 7s would work.
Yes, got english version. The chip with english firmware is on the way.

My review after one week using it.
Pro
1) Beautiful screen with detail info on each cell.
2) Has current shunt to calculate power in and out in AH.
3) Has many temperature probe. Not useful in Malaysia tho.
4) Can connect relay to cut off power
5) Can connect to multiple battery management board. 1 master board + many battery board (The board with lots of big resistors)
6) Has english version
7) Seller knows a lot about the product.
Cons
1) The bluetooth module and screen driver not stable and half broke. Parts in on the way and cheap (rmb20).
2) Cannot do active balance. Only do balance by dissipating power. Wasted precious solar energy!!!
3) Lots of wire and assembly to so. Difficult for user without proper tooling.

Now I am testing another product that can do active and passive balancing...

This is just a battery balancer ?

Or with BMS that got protection voltage/amp setting ?

With the large capacity battery, you need an active high amp balancing. Otherwise forever can't balance it.

saw this youtuber doing this DIY solar....https://www.youtube.com/user/errolprowse

If you are comfortable with it then I guess it's okay to do so. I'm going to stay in the same house so I rather make sure there is someone who knows what they are doing to have a look at it. Someone like an electrician. I'm not sure also whether will your house insurance cover all these DIY stuff. I saw on his latest video, his example setup is for 2 solar panels only. When you need like 16 of it, there is a lot of work to be done.

The one with small screen?
It has over / under voltage protection per cell. If trigger will shut off the relay.

For over current protection I use fuse and DC circuit breaker(48v250A). Overcurrent protection base on mosfet in my situation is too expensive.

Active balancing current can go up to 4A, so in the manual it require you to use larger than 0.5mm cable.

The battery is in the middle of discharging at 30A now, voltage diff between high/low cell is 0.05v. seems ok.

I m still looking for a programmable setting BMS. But mostly have a very low Amp balancer.

Maybe I just separate it out BMS and get another active balancer board.

Waaa, how many amps you need and how big is your battery?
The 2 active balancer I have can pump current between 1-4 amps depending on cell voltage difference.

Or you can consider using arduino to scan voltage of all cells, then trigger a relay to charge the lower cell at 3.3v 40amps from a smps. 

1-2A enough liau la. 

The different is because you're using lipo while I using li-ion. Li-ion consist of many cell. Not easy to takecare many cell. Each behave differently. Somemore mix brand pana, LG samsung etc..

I want programable BMS cause I don't want to charge max to 4.2v and program it cutoff voltage.

Hmm, all bms I have on hand can program cell voltage, eg : 2.7 to 3.5v per cell. I never charge the cell to max 3.65v so cell can last long time.
The BMS will burn off power that exceed 3.5v, if cell goes below 2.7v relay will turn off.

One big non-flamable cell is easier to manage. 
But if cell spoil painful to the wallet.

Ya, very expensive with the big capacity.

If 1 dead in future, might not be easy get if manufacturing change capacity or no more sell. Than whole power bank cannot use. 

LiFePO4 cell puncture test. Lots of smoke, no fire.
I wouldn't put the battery inside my house, outside at the car posh with open air circulation still ok lar.

Yup. Can’t put the battery indoor. Specially lithium type.

My leadfree acid is indoor. 😔

And you need to have fire extinguishers and a bucket of sand beside for emergency.

Talking about battery lifetime, yesterday night found out 1 of the ups battery crack open and running hot. Lucky no fire. But not sure the liquid got spill out. Battery only 2yrs old.

Eh... I tot lead acid battery are very robust and don't crack or burn?

But you say is true lar, I just finish moving large batteries from inside of my house to house them in car posh.
Those smaller individual 18650 can't be moved, maybe should store them inside a solid metal box.

Well if you just need smaller scale solar like 5kw, hybrid type.
Nowadays it only costs about 22k.
However you won't be able to connect your whole house to the inverter.
Choose those power hungry device like aircond and fridge, they are usually the cause of high electric bill.

RM22k for DIY or contractor?
Why unable to connect whole house to the inverter?

Hi guys, I do a lot of DIY at home but I'm new to solar power generation setup.

If I want a small-scale offgrid type, let's say maybe 200w/h for 8hours to power my led lights for hydroponics purpose:

I need 2 pieces of 270watts panel from lazada/shopee only? What about all these other items that i read from the last few pages of this forum? ie controller, inverter, battery, dc cable, switch box etc etc? What else do I need and what is the rough cost??

Thanks a bunch