Where do I put my battery storage?

[Thorfun]

as the title says 'where do I put my battery storage?'. I have a few options and I want to ensure I choose the best place for safety, performance and expandability. I have a LuxPower Squirrel POD inverter and 2 x Greenlinx 3.2kWh batteries at the moment but plan to potentially add more batteries and another SQPOD in the future to expand the system. The batteries are LFP(LiFeP04) cell type (which I believe is the safer of the Lithium Ion battery chemistry) and are IP54 rated. the inverter is IP65 rated but the instructions say to not expose to direct sunlight, rain or snow. so basically if installed externally to keep it covered.

 

Below is a plan of the ground floor of our house. I have marked up the location of the PV inverter in the loft and the CU in the plant room in the basement which is approx 20m cable run from the PV inverter.

 

 

I was originally going to put the SQPOD and batteries in the Cup'd in the garage but was concerned about the loss of efficiency running all that way from the PV inverter and then back to the CU in the basement. Also it's quite a small cupboard and the MI instructions for the SQPOD states the following clearance requirements so it might be a bit tight:

 

 

I could put it in the garage which has a lot more space but, again, surely some massive inefficiencies for running the cable that distance.

 

so, now I'm thinking of putting it in the electrics/comms plant room in the basement so it's next to the CU. but I'm now worried about safety and the potential for Li-Ion fires. the basement is built from waterproof concrete and has B&B above which will, eventually, be covered in a 50mm liquid screed. Am I worrying about nothing and is that the best place for it?

 

I could, I suppose, build a shed for it externally but that seems a little excessive and also how will the temperature fluctuations of the outside world affect the performance of the system? the basement should be a constant temperature and even in the recent heatwave it never got above 23°C and we haven't even finished the insulation/airtightness yet.

 

any comments on this please?

[Nickfromwales]

38 minutes ago, Thorfun said:

massive inefficiencies

I doubt they’re massive tbh, so I’d stop worrying about that and look at practicality.
Go with the garage, as when converted to AC all you “need” to do is upsize the cable to combat any losses vs distance. Say upgrade from a 4mm2 cable to a 6mm2 cable for eg.

Done jobs where we’ve run the AC for 135m ( ground mounted PV with external inverter ) and was still performing extremely well as we upsized the SWA back to the CU. 
 

I think you’re over thinking a little. It’s all within the footprint of a single domestic dwelling so afaic you can relax a little and just apply a little sensible mitigation to get the best result from a practical installation   

Edited August 24, 2022 by Nickfromwales

[Radian]

There may be a restriction due to CT placement have you considered that? I wanted to install AC coupled battery in a detached garage next to the inverter for a PV on the roof but the installation is on a sub main 25m away from the CU and meter tails in the house. The battery systems all seem to need a CT cable back to the meter.

[Marvin]

If running at low voltage like my 12v DC system, the nearer the panels to the storage the better because of the voltage drop. Also installed large cable between, batteries and pure sine wave inverter and kept them as close as possible.

 

As soon as you convert to 240 AC normal cable rules apply. 

 

The 150ish DC volt system I upgraded to 6mm cables as I expect to benefit from thisforthenext 20 years.

 

I think the distances around your inverter is because it can become hot. So again best not in a cupboard.

[Marvin]

2 minutes ago, Radian said:

There may be a restriction due to CT placement have you considered that? I wanted to install AC coupled battery in a detached garage next to the inverter for a PV on the roof but the installation is on a sub main 25m away from the CU and meter tails in the house. The battery systems all seem to need a CT cable back to the meter.

In our case, extended CT cable with Cat 5.

[kommando]

I picked a meter with RS485 output and use wireless RS485 adaptors to send the signal to a data logger which also can restrict feed in and turn on loads. The same wireless adaptors cover the RS485 coms with the inverters. So I can spread all my kit all over the property and only have to consider the voltage drop on the AC cables and ignore losses of the RS485 plus it stops lightening surges using long RS485 cables.

[Thorfun]

1 hour ago, Nickfromwales said:

I doubt they’re massive tbh, so I’d stop worrying about that and look at practicality.
Go with the garage, as when converted to AC all you “need” to do is upsize the cable to combat any losses vs distance. Say upgrade from a 4mm2 cable to a 6mm2 cable for eg.

Done jobs where we’ve run the AC for 135m ( ground mounted PV with external inverter ) and was still performing extremely well as we upsized the SWA back to the CU. 
 

I think you’re over thinking a little. It’s all within the footprint of a single domestic dwelling so afaic you can relax a little and just apply a little sensible mitigation to get the best result from a practical installation   

thanks Nick. so I'll forget inefficiencies, that's one headache down. the garage is attached to the house and is timber frame whereas the basement is concrete. from a safety perspective would it be better in the basement rather than garage or am I ****** either way if they combust?

[Thorfun]

1 hour ago, Radian said:

There may be a restriction due to CT placement have you considered that? I wanted to install AC coupled battery in a detached garage next to the inverter for a PV on the roof but the installation is on a sub main 25m away from the CU and meter tails in the house. The battery systems all seem to need a CT cable back to the meter.

our meter is 25m from the plant room in an external cabinet on the boundary so I hope I don't have to run the CT back to the meter! will speak to the electrician about it next week when he's here.

[Thorfun]

1 hour ago, Marvin said:

If running at low voltage like my 12v DC system, the nearer the panels to the storage the better because of the voltage drop. Also installed large cable between, batteries and pure sine wave inverter and kept them as close as possible.

 

As soon as you convert to 240 AC normal cable rules apply. 

 

The 150ish DC volt system I upgraded to 6mm cables as I expect to benefit from thisforthenext 20 years.

 

I think the distances around your inverter is because it can become hot. So again best not in a cupboard.

thanks. the electricity is converted to AC by the PV inverter in the loft so I don't have to worry about that apart from the upsizing of the cables.

 

the plant room for my electrics is pretty much a cupboard. it's about 1.7m x 1.4m and will also have my Loxone cabinet, CU and network/server rack in it. so that room will get warm but it has an MVHR extract in it and 3m high ceilings so I'm hoping that the warm air will rise to the ceiling and get extracted! plus it's underground so will be cooler than elsewhere in the house.

 

then again, maybe the garage is the best place for it, just not in the cupboard. I've got loads of space there. ahh man....I just don't know and I've so many other things to think about as well. this self-building malarky is tricky when you're winging it! 😂

[Onoff]

3 hours ago, Thorfun said:

as the title says 'where do I put my battery storage?'.

 

My house? 😂

[Marvin]

4 hours ago, Thorfun said:

thanks. the electricity is converted to AC by the PV inverter in the loft so I don't have to worry about that apart from the upsizing of the cables.

 

the plant room for my electrics is pretty much a cupboard. it's about 1.7m x 1.4m and will also have my Loxone cabinet, CU and network/server rack in it. so that room will get warm but it has an MVHR extract in it and 3m high ceilings so I'm hoping that the warm air will rise to the ceiling and get extracted! plus it's underground so will be cooler than elsewhere in the house.

 

then again, maybe the garage is the best place for it, just not in the cupboard. I've got loads of space there. ahh man....I just don't know and I've so many other things to think about as well. this self-building malarky is tricky when you're winging it! 😂

Having read up on the LuxPower Squirrel POD inverter system I would suggest that you work out how much more storage you have on your wish list and see if it will all fit near the consumer unit in the cupboard or aim for the garage ensuring you have a suitable ampage 240v cable to carry your expected peak demand, over the distance between CU and POD inverter and installed in a fashion suitable for the ampage. 

 

I'm sure you know concrete is used for massing in a building. If the cupboard gets hot and the concrete walls warm up it will take ages to cool down.

My inverter manual says do not touch it can get hot....

 

Probably best to speak to supplier about what you hope to put in cupboard and ask about overheating.

 

[Thorfun]

8 minutes ago, Marvin said:

Having read up on the LuxPower Squirrel POD inverter system I would suggest that you work out how much more storage you have on your wish list and see if it will all fit near the consumer unit in the cupboard or aim for the garage ensuring you have a suitable ampage 240v cable to carry your expected peak demand, over the distance between CU and POD inverter and installed in a fashion suitable for the ampage. 

 

I'm sure you know concrete is used for massing in a building. If the cupboard gets hot and the concrete walls warm up it will take ages to cool down.

My inverter manual says do not touch it can get hot....

 

Probably best to speak to supplier about what you hope to put in cupboard and ask about overheating.

 

I have enough space in the comms room to fit my proposed expansion plans near the CU. space is tight but I can make it work.

 

I've sent an email to the supplier to ask for assistance and am awaiting a response. I'll chase it up soon if I don't hear anything back.

 

it just seems such a waste to have a long cable carrying electricity back and forth between the batteries in the garage and the CU in the basement. that's why I thought having the batteries next to the CU would be best. but, it appears that those potential inefficiencies won't manifest themselves and so I guess my decision comes down to safety and convenience!

 

good point about the concrete wall storing the heat though. I hadn't considered that.

[Pocster]

3 hours ago, Thorfun said:

I have enough space in the comms room to fit my proposed expansion plans near the CU. space is tight but I can make it work.

 

I've sent an email to the supplier to ask for assistance and am awaiting a response. I'll chase it up soon if I don't hear anything back.

 

it just seems such a waste to have a long cable carrying electricity back and forth between the batteries in the garage and the CU in the basement. that's why I thought having the batteries next to the CU would be best. but, it appears that those potential inefficiencies won't manifest themselves and so I guess my decision comes down to safety and convenience!

 

good point about the concrete wall storing the heat though. I hadn't considered that.

Didn’t read any of your posts as don’t need too . You put them outside . Easy to expand ; and cool ( assuming direct sunlight isn’t cooking them ) . You know I’m right because that’s what I did .

[Pocster]

8 hours ago, Thorfun said:

when you're winging it! 😂

(expletive deleted)ing tell me about it 

[Thorfun]

30 minutes ago, pocster said:

Didn’t read any of your posts as don’t need too . You put them outside . Easy to expand ; and cool ( assuming direct sunlight isn’t cooking them ) . You know I’m right because that’s what I did .

I'm kind of loathe to put them outside to be honest as we're surrounded by trees and anything that's outside for more than 5 minutes gets spiders on them making webs! plus, I don't really have anywhere out of direct sunlight to put them that doesn't spoil the external facade of the house. even if I built a shed for them we have hornets, wasps, bats, spiders that like to nest in our existing shed so, again, kind of loathe to do it.

[Pocster]

2 minutes ago, Thorfun said:

I'm kind of loathe to put them outside to be honest as we're surrounded by trees and anything that's outside for more than 5 minutes gets spiders on them making webs! plus, I don't really have anywhere out of direct sunlight to put them that doesn't spoil the external facade of the house. even if I built a shed for them we have hornets, wasps, bats, spiders that like to nest in our existing shed so, again, kind of loathe to do it.

Don’t be a pussy . Outside with a little cover over them to keep direct sunlight off . (expletive deleted) the spiders / bats / unicorns. You in Narnia or U.K. ?

[Thorfun]

so I've gone against the advice and have installed them in the basement. After speaking to the suppliers who've stated they have never had a battery catch fire and have also said that I can fit a DC breaker (80V/125A) which will reduce the risk of cable fire I am confident that they're safe in the basement. there's probably more chance of our washing machine causing a fire!**

 

so, today I fitted the Squirrel Pod and the 2 x 3.2kWh batteries and it looks very nice and neat with plenty of space below for more batteries should the need arise.

 

 

 

now just waiting on the Solar PV inverter to be installed and commissioned next week and then I can get the electrician back in to wire the batteries up and can start making use of our free energy!

 

** I have no data to back that statement up

[Radian]

I'm jealous. Very neat!

[Thorfun]

12 minutes ago, Radian said:

I'm jealous. Very neat!

Probably coz there’s no cables at the moment! 😂

[Pocster]

1 hour ago, Thorfun said:

so I've gone against the advice and have installed them in the basement. After speaking to the suppliers who've stated they have never had a battery catch fire and have also said that I can fit a DC breaker (80V/125A) which will reduce the risk of cable fire I am confident that they're safe in the basement. there's probably more chance of our washing machine causing a fire!**

 

so, today I fitted the Squirrel Pod and the 2 x 3.2kWh batteries and it looks very nice and neat with plenty of space below for more batteries should the need arise.

 

 

 

now just waiting on the Solar PV inverter to be installed and commissioned next week and then I can get the electrician back in to wire the batteries up and can start making use of our free energy!

 

** I have no data to back that statement up

You’re going to burn to death when they over heat next summer ! 🤟

[Thorfun]

3 minutes ago, pocster said:

You’re going to burn to death when they over heat next summer ! 🤟

In a basement? With MVHR extract? Nah. 😉

[Pocster]

2 minutes ago, Thorfun said:

In a basement? With MVHR extract? Nah. 😉

Lol ! We shall wait and see the “ my batteries in my basement caught on fire “ post … 😋

Edited September 16, 2022 by pocster

[SteamyTea]

10 hours ago, pocster said:

We shall wait and see the “ my batteries in my basement caught on fire “ post

Plenty of room for one of these.

[offthepiste]

I would not want to have a battery located in doors, so have selected one of the few (I think) that be located outside, i.e Powerwall. The new Enphase batteries can also be located outdoors but do not seem available in UK yet and I think there is a German model also.

 

My rationale is fire risk. I appreciate that Solar PV panels can also cause fires - so have gone for micro inverters.

 

Reasoning is based on quite a few years in the speciality renewable energy insurance market, e.g. insuring large Solar PV install in the US - many on roofs and with batteries, and the various real losses that occurred. 

 

[Radian]

Interesting topic. While I have seen reports of Rooftop solar PV causing fires on roofs, I've not seen reports of problems with inverters or battery systems. I'll agree, I'd rather not have Lithium batteries of any variety indoors, due to the difficulty of extinguishing the flame they produce although I can't find out for certain if  LiFePO₄  batteries have the same characteristic. They have been shown to be safer if punctured or overheated so are preferred for those reasons.

Edited October 7, 2022 by Radian