scalability of LifePO4, an insane® battery pack.

[brandnewb]

@houseofancients thank you for the headsup, I will be sure to not exceed 48 volts then as I was having difficulty finding examples of bigger grid tie inverters anyway. Let alone the safety issues I have been warned about earlier in this thread.

I do prefer English though so that everyone can follow without having to translate to engligh using an online translator
But that is not to say I am not thankful for the advice.

 

[brandnewb]

I'll provide the translation fo what @houseofancients wrote (sorry for the poor formatting, translate.google.com)

384v is not legal in the Netherlands, but I think you are overestimating the required voltage. to give you an example : 16 cells in series is 48v (the common voltage for home batteries and inverters) if you put 280ah cells in 1 series, you effectively have 14.4 kW. that means you can use 14.4 for an hour. if you put 32 cells in 2 series, you still have 48v, but you have 28.8 kW at your disposal. this multiplies this so much there is not a single (affordable and approved for residential use as far as I know) inverter available that supports more than 48v nominally. that's not necessary either. if you look at for example the Deye 12kw 3 phase, or the mpp solar 10kw mpi 3 phase , which deliver on each individual phase 12 and 10 kWh respectively. you can stack these, which means doubling, so 2 inverters become 24 kW and 20 kW. there will be few residential ev chargers that can handle more power. you are confusing KW (kilowatt = power) and KWH (power over time)

 

[brandnewb]

I could not find a seller nearby for the Deye 3 phase, found one in ZA for 2.658,08 Euro excluding shipping if they even do.
EDIT;
But that would eliminate the need for having 2 of them for each phase would it?
But that would eliminate the need for having 2 additional ones for the remaining 2 phases would it?

 

[John Frum]

can you please elaborate some more regarding the dead empty and dead full? I am not sure but do you mean it won't work?

dead empty = completely empty
dead full = completely full

 

[brandnewb]

completely

I am a bit ashamed at the moment for not catching that directly

 

[brandnewb]

I marked this thread as solved. I will not be going any higher than 48 volts. Any more input from you guys is of course more than welcome.

EDIT; I unmarked it again in the meantime as now the challange is how to be able to draw 20KW from the battery bank

 

[John Frum]

I am a bit ashamed at the moment for not catching that directly

Don't be.
I need to work on my use of idiom.

 

[John Frum]

I marked this thread as solved. I will not be going any higher than 48 volts. Any more input from you guys is of course more than welcome.

Do you really need ~230 thousand watt hours of capacity?

 

[brandnewb]

Do you really need ~230 thousand watt hours of capacity?

THat KWh was the result of going for 384 volts. so it was completly baseless and misguided on my part.

I have not gotten around yet to actually calculating how much I realistically need.

All I know is that I currently draw +- 9000 KWh more from the mains grid than I supply to it in one year. That needs to be dealt with ASAP
ANd then again, starting from 2023 we are gradually being allowed less and less equal compensation for supplied vs drawn power of the grid so it is now more than ever important to go for self sustainability

 

[houseofancients]

I could not find a seller nearby for the Deye 3 phase, found one in ZA for 2.658,08 Euro excluding shipping if they even do.
EDIT;
But that would eliminate the need for having 2 of them for each phase would it?
But that would eliminate the need for having 2 additional ones for the remaining 2 phases would it?

you can order the from alibaba..
if that scares you, i order my mpp solar / voltronic gear in italy , as i love eu warrantee and support

solarpower24.it



btw i pref english too, as that is my mother tongue, but sometimes it helps to understand if someone does so in je moedertaal

 

[brandnewb]

btw i pref english too, as that is my mother tongue, but sometimes it helps to understand if someone does so in je moedertaal

Understood

 

[brandnewb]

I am continuing this discussion in another thread

9000KWh reliance on grid is no good; how to avoid?

Currently I draw +- 9000 KWh more from the mains grid than I supply to it in one year. Earlier I posted this thread https://diysolarforum.com/threads/solved-scalability-of-lifepo4-an-insane-battery-pack.30202/ That started it all TL;DR I have an 11kw 3 phase EV charge, I 3KW single phase heat...

diysolarforum.com

Any input from you guys is well respected

 

[Short_Shot]

At that scale you're probably better off, though it won't be cheaper, buying commercial tesla gear.

 

[brandnewb]

At that scale you're probably better off, though it won't be cheaper, buying commercial tesla gear

I'd like to avoid tesla if possible. I do not like their anti right to repair mentality

 

[Short_Shot]

I'd like to avoid tesla if possible. I do not like their anti right to repair mentality

Well. That "type" of hardware.

 

[brandnewb]

Well. That "type" of hardware.

My apologies but I am not sure what you meant with that ;(

 

[Short_Shot]

My apologies but I am not sure what you meant with that ;(

Commercial scale battery backup hardware. Tesla isn't the only game on the block.

 

[brandnewb]

ahh ok understood. I did settle on an 48 volt battery system though. Now I still only need to figure out how many, if any, more of those I need in parallel.

Do you still see commercial scale hardware as viable in that scenario?

 

[toms]

This would be the cheapest “off the shelf” system i would have powering my place.

There are cheaper options - i’m not the one to talk to regarding them.

 

[brandnewb]

Please see

9000KWh reliance on grid is no good; how to avoid?

Currently I draw +- 9000 KWh more from the mains grid than I supply to it in one year. Earlier I posted this thread https://diysolarforum.com/threads/solved-scalability-of-lifepo4-an-insane-battery-pack.30202/ That started it all TL;DR I have an 11kw 3 phase EV charge, I 3KW single phase heat...

diysolarforum.com

TL;DR
I am aiming for a 20KW load continuesly

I have removed the solved mark as now comes the challenge of creating a battery pack that can do it.
I have ordered 16 x 3.2V 280Ah LifePO4 cells in the mean time. Which will be 16s for +- 48V at 280 Ah.
I am not sure yet regarding the C rating and what it is exactly and if it is relevant. But I could imagine the 16s configuration is not able to supply that load is it? And if not would it help to go 16sNp?