scalability of LifePO4, an insane® battery pack.

[wattmatters]

I am aiming for a 20KW load continuesly

Yikes.

48V at 280 Ah

= 13.4kWh, minus some safety allowance and longevity. Call it 12kWh.

You really don't want to be discharging at 20kW on the AC side with a battery of that size. After inverter losses you won't last half an hour and it would not be good for the battery's health.

 

[740GLE]

Buy 10 of these guys, while small Ah per unit, they are scalable, plug and play is probably the way to go instead of having to babysit multiple DIY batteries. If you find 10 being too small snag another 10.

EG4 48V 100AH LiFePower4 Battery

ADD-ON CHARGER DEAL Get the 25A 48v LIFEPO4 Charger for 33% off in cart DESCRIPTION SPECS & MANUAL VIDEOS SHIPPING 48V EG4-Lifepower4 Signature Solar’s premier lithium battery, GYLL, has been rebranded to EG4. You can expect the same great battery with the same top-of-the-line, Tier One, A+ Cell...

www.signaturesolar.us

Also report back if those Alibaba 280ah cells even show up at your door, so many scams out there.

 

[brandnewb]

You really don't want to be discharging at 20kW on the AC side with a battery of that size. After inverter losses you won't last half an hour and it would not be good for the battery's health.

yes I believe you are completely right. This is why the question now is how to I configure the pack to be able to do it?
16s4p for example?

 

[brandnewb]

Also report back if those Alibaba 280ah cells even show up at your door, so many scams out there

I purchased 16 cells of which the seller guarantees they are brand new A grade with qr code and perform as advertised. They were more expensive than other listings though that dodged my question about guarantees.

But sure I'll keep you guys updated

 

[brandnewb]

= 13.4kWh, minus some safety allowance and longevity. Call it 12kWh.

Ok so for the EV car alone charging at 11KW and a capacity of 22KW i'll need 16s2p right?

 

[John Frum]

Ok so for the EV car alone charging at 11KW and a capacity of 22KW i'll need 16s2p right?

Instantaneous current is amps.
Battery capacity is amp hours.
Watts = volts * amps = power
Watts * hours = work

A 16s2p battery comprised of 280 amp hour cells is 560 amp hours at 51.2 volts nominal.

11000 watts / 51.2 nominal volts = 214.84375 amps
560 amp hours / 214.84375 amps = 2.606545455 hours

 

[740GLE]

To charge an EV with a 100kwr battery via stored solar energy, Id wager you’d want 5x that much in storage and adequate solar to replenish those batteries. Such that you’d want to only cycle the battery 90%-50% depth of discharge over the course of a few days, that way you’d be able to deal with low solar production. That’s be about 100 of those Eg4 batteries, if you start out with say 10 of them see how they work and just order more.

Yeah sure you won’t be charging the car from zero to full each day, but if your cutting the cord from the grid you need to take into account low low production days.

Also I don’t think anyone has ever said they wish they bought less batteries. Lol.

 

[wattmatters]

Ok so for the EV car alone charging at 11KW and a capacity of 22KW i'll need 16s2p right?

You are confusing power and energy, which makes answering your questions guesswork on our part.

Do you mean your EV has a 22kWh battery? A Renault Zoe?

EV car alone charging at 11KW

Do you really need to run an EV charger at 11kW all the time?

I can understand if you do a long morning drive, run out of charge and need to charge up as quickly as possible so you can a drive again later that day (in which case I'd be going to a fast charging station, not going home). If instead you are mostly expecting to charge your EV overnight, then it doesn't need to charge at 11kW.

If the EV is 22kWh (not sure, hard to say until you confirm) then an 11kW charger will fill it in ~2 hours. It may take a little longer to get right up to 100% as often the charge rate is reduced as the battery reaches high state of charge.

But if say it is parked overnight and can be charging for 8 hours, then it only needs to be charging at 22kWh / 8 hours = 2.75kW (on the AC side). And if the EV battery has not been fully discharged and is instead only needing 10kWh of recharge, then over 8 hours it only needs to be charged at 1.25kW.

i'll need 16s2p right

16s2p is just the configuration of a battery pack. It does not tell us how much energy capacity that pack has.

If you mean 280Ah cells, then 16s2p would be a 48V (nominal) x 280Ah x 2 =26.8kWh (nominal). That would be the absolute minimum required to fully charge a depleted 22kWh EV battery.

Of course this assumes on that day your solar PV system was able to generate enough energy to fully charge your home battery (as well as supply energy to everything else). What happens when the weather is not so good for a few days (or a week or more) and you no longer have the grid to supplement your needs?

What home EV charging solution is suitable for your EV will depend on many things...
How much you drive / how much energy your EV uses each day/week.
When the car is parked at home and can be charged (during the day or only at night)
Typically how long can it be plugged in for.
How much storage and PV capacity you need to get through long periods of poor solar production.

Without doing a basic energy audit, talk of what size battery pack or what sort of charger you need is pointless.

This is almost literally putting the cart (EV) before the horse (power).

 

[brandnewb]

@smoothJoey cool thx, it enabled me to calculate.i'll reserver a 24h/day load for the heatpump of 3KW

You are confusing power and energy, which makes answering your questions guesswork on our part.

Do you mean your EV has a 22kWh battery? A Renault Zoe?

indeed. So as a user of it I strongly recommend against that car

 

[brandnewb]

Do you really need to run an EV charger at 11kW all the time?

My 3 phase charger has 3 modes. 6a, 10a and 16a. that damned zoe only accepts 16a though thus 11kw. one of the reason I strongly recommend against that car

 

[brandnewb]

What home EV charging solution is suitable for your EV will depend on many things...

I am essentialy asking how to configure cells to get 20KW output sustained until depleted

 

[wattmatters]

My 3 phase charger has 3 modes. 6a, 10a and 16a. that damned zoe only accepts 16a though thus 11kw. one of the reason I strongly recommend against that car

Surely it must have a single phase charger available to plug into a regular power outlet?

 

[brandnewb]

16s2p is just the configuration of a battery pack. It does not tell us how much energy capacity that pack has.

If you mean 280Ah cells,

yes that is what I meant. For now I am thinking in 3.2v 280A cells

 

[wattmatters]

I am essentialy asking how to configure cells to get 20KW output sustained until depleted

Then be prepared for a very big budget for your off-grid system. Using the grid will be cheaper...

 

[Smokin]

20Kw Diesel Generator

 

[wattmatters]

20Kw Diesel Generator

Even then using the grid will still be cheaper. I guess you could make your own diesel. Even that's debatable if it would be cheaper than the grid. Depends on the cost of your source of oil.

The average retail electricity rate in the Netherlands is ~US$0.19/kWh inclusive of all fees, charges and taxes.

 

[houseofancients]

Even then using the grid will still be cheaper. I guess you could make your own diesel. Even that's debatable if it would be cheaper than the grid. Depends on the cost of your source of oil.

The average retail electricity rate in the Netherlands is ~US$0.19/kWh inclusive of all fees, charges and taxes.

well, as of late not so much..
and i think this is why the OP is very interested in getting fully off grid right now.

y'all might have missed it, but large parts of northern europe are in a bit of an energy/gas crisis atm

 

[wattmatters]

y'all might have missed it, but large parts of northern europe are in a bit of an energy/gas crisis atm

No, I haven't missed it.

Retail electricity prices don't fluctuate up and down in the manner wholesale markets do though. That's only an issue if you choose a wholesale pass through plan.

In the Netherlands retailers have to submit a proposal for introduction of new tariffs or for changes to existing tariffs to the market regulator some four weeks in advance. The regulator assesses the proposal and may or may not reject it depending on whether it considers the tariffs to be excessive.

Gas prices do definitely influence wholesale electricity prices in the Netherlands as they have significant reliance on gas power plants for both general and peaking electricity supply. But price rises to consumers are significantly dampened by the way the retail market operates.

 

[740GLE]

In NH, a local regulated utility just raised their energy supply portion +100% due to current “energy crisis”. Went from .07 to .17 for energy supply portion of the bill. All in it’s gonna be +.23kwhr for customers

The future is now

 

[brandnewb]

Surely it must have a single phase charger available to plug into a regular power outlet?

Yes we have a single phase granny charger as well that uses a regular wall socket connection to charge at like 2.5KW max. But Renault recomended against using that as it was not meant for daily use, only emergencies.
The one that told me was no technician though so it might be bullocks and if we can use that without any issues I think your tip has just made my mission a whole let less expensive.