Battery location

[CalvinHobbes]

The solar guy said we should not put the battery outside since doing so in our wet cold location will mean it will discharge, (he wants the meter and batteries in the utility room)having had an electric car, a little zoe over a winter I can see what he means. That said the electrician is adamant we dont put it inside saying battery fires are terrible (He wants the meter in the cupboard behind the porch). We don't have a garage. So I was thinking we could put it in the porch but that is open on one side and outside the thermal envelope

The electrican wants to put it outside in some sort of hut.

Oh and thanks I have gone back and asked for the 3 phase inverter that is hybrid and acceptable to give energy to the grid.

[joe90]

Yes genuine worry I guess, just searched the web and found this.

Li-Ion cells will become compromised if stored below 0 degrees. We do not therefore recommend storing in a shed or garage over winter as temperatures in these areas can drop below zero. Equally, avoid a storage area with direct sunlight as higher temperatures can equally accelerate the battery's ageing.

 

and as you said. Battery efficiency diminishes with temperature. I am surprised there are no building regs on where/how they are installed (1 hour fire door and plasterboard!!!!).

[Mr Blobby]

1 hour ago, CalvinHobbes said:

saying battery fires are terrible

 

What battery are you installing? 

My understanding is that the fire risk with LFP lithium ion phosphate batterries is greatly reduced.  We plan to install a pylontech force battery which is LFP (someone correct me here please if this is not the case!)

 

We are also installing 3-phase inverter and 3-phase supply into the house.  Our inverter and battery anre going in the garage which should be the goldilocks temperature of not too hot and not too cold.  And outside the thermal envelope to keep the heat out of the house in the summer time.

Edited April 29 by Mr Blobby

[CalvinHobbes]

I think we will just put up a 6kw array and in the future plan to up that to 12 and put a battery in was thinking lippy I hear they are due to release a 3 phase battery. Just planning ahead. Unsure of battery. Have asked that the inverter be 3 phase and hybrid. Just wondering about the tesla powerwall, it can be outside. I wonder how it does in -5 degrees and with 3 phase?

[garrymartin]

The Tesla Powerwall can operate down to -20°C, but they don't recommend that for extended periods. They do a cold weather kit if you expect prolonged periods below -10°C.

 

In my "planning" activities whilst waiting on our appeal, I'm seriously questioning whether to put a battery in at the beginning. The technology is getting better all the time, and they continue to drop in price, so I'm edging towards making space provision for it but using the money saved for other things. Given any future build will be to Passivhaus specification, and the instances of complete power loss are statistically low and short in duration for the area where we'll be building, I'm more inclined to plan overnight cheap rate use of power for ASHP slab UFH and DHW (less cost per unit than will be recovered by the daytime solar export), and maybe install some north-facing panels in conjunction with the south-facing ones to get a longer solar production day and better winter performance.

 

In the short term, that might be the best return on investment for me. Your mileage may of course vary.

 

 

[S2D2]

Don't put it outside, charge/discharge rates will be crippled in cold weather or it'll use a resistance heater to avoid that issue, a waste of the stored energy.

[JohnMo]

3 hours ago, CalvinHobbes said:

That said the electrician is adamant we dont put it inside saying battery fires are terrible

Fire and fire risk really depends on technology used for the battery.

 

1st write-up I found

https://www.fogstar.co.uk/blogs/fogstar-blog/how-safe-are-lifepo4-batteries

[Bramco]

9 minutes ago, JohnMo said:

Fire and fire risk really depends on technology used for the battery.

 

1st write-up I found

https://www.fogstar.co.uk/blogs/fogstar-blog/how-safe-are-lifepo4-batteries

 

V useful.  Here's another one -> https://batteryhacker.com/can-lifepo4-batteries-catch-fire/.

 

Both say, for LiFePO4, which most packaged systems are, charge properly and have a BMS - which all packaged systems have afaik. And they don't catch fire themselves, so if there is a fire they won't add to it.

 

Simon

[Alan Ambrose]

Well it's all clear, you shouldn't put it inside.

 

And you shouldn't put it outside.

 

What's the problem? 

[billt]

5 hours ago, S2D2 said:

Don't put it outside, charge/discharge rates will be crippled in cold weather or it'll use a resistance heater to avoid that issue, a waste of the stored energy.

 

Why not unless you're in an area that experiences extreme cold? Ours are outside and haven't had a problem with cold yet. I have installed heaters but they haven't been needed yet and the amount of energy that they would use is fairly minimal. Another alternative is just to switch them off during the infrequent cold spells.

[CalvinHobbes]

So went to the fire station. After a debate they agreed what they would do is put them in the utility room with a heat sensor. As long as branded batteries installed by MCs then grand.

[JohnMo]

Mine is in plant room. GivEnergy all in one - MCS install.

[PNAmble]

Ours in plant room (GivEnergy Inverter and battery).  Added a heat and smoke detector. 
 

PAS 6300:2024 only recommends against loft installs.  Plus it groups LI-Ion in same fire risk as LiPo which they arent. 

[S2D2]

2 hours ago, billt said:

 

Why not unless you're in an area that experiences extreme cold? Ours are outside and haven't had a problem with cold yet. I have installed heaters but they haven't been needed yet and the amount of energy that they would use is fairly minimal. Another alternative is just to switch them off during the infrequent cold spells.

There's a lot of variables, so YMMV but I've seen thermal clipping of discharge rate and mine is in an integrated garage. The installer groups are full of customers asking why they're importing from the grid when the battery has charge and usually the answer is the battery is too cold. If you have enough headroom in discharge rate then you'll never even notice - you'll probably never notice if the heater is keeping the battery warm either. It's just an inefficiency you can skip if you have space inside, but it's not the end of the world if outside is your only choice.