Practical experience of Hybrid and 9.5 in loft ?

Still waiting for my install, but I have the choice of fitting the hybrid and battery in the loft or the garage(integral/attached). Loft would be out of the way, but I have seen different opinions on both the practicality of 110 Kg batteries in the loft, and temperature swings affecting inverter/ battery at either extreme of summer or winter.

Anyone here had an install thats been through last years roasting summer and this recent chilly winter ? Have you regretted putting it in the loft, it or is no trouble at all ?

My installer refused to put battery in loft due to man handling issues associated with weight of 8.2kwh battery (100kg). I didn't want it in the loft due to heat issues in the summer and poor access. My install is in the garage and this has worked out very well......easy access and plenty of room for expansion. No problems with heat during the summer and a blanket over the battery keeps it toasty in the winter.

justpassing likely you’ll end up putting additional fans under the inverter wherever it goes, simply because you want to keep the temp reasonable. Ours is in the old airing cupboard to make use of space. It gets warm in summer (lots of PV) and helps keep the dead space warm in winter. There’s no “right answer”, just what works for you. Remember that the data sheet says it’s good over a wide range of ambient temperature and it’s not up to you to find the perfect environment for it; that’s the privilege of your children.

justpassing My system has pretty much behaved itself since installation but I have still had to reset the inverter once and power cycle the battery once. Plus if the app or portal have missing data it's useful to check the dongle connection status (lights). You should put it in the garage unless there's a very good reason for hauling it to the loft and shutting it away.

Yes getting 110kg in to a loft could be an interesting challenge…

Wb1 Also, make sure your wifi signal is strong enough up there. Most IP standard routers have limited range vertically and maximum range horizonally.

Thank you all for your replies, all votes for the garage. I guess either nobody puts the battery in the loft, or have but don't want to admit it. 😀

I have seen a number of installation photos in loft spaces, but they tend to have multiple 2.6 kWh batteries which are more manageable weight wise than the 110 kg of a single 9.5 kWh battery.

justpassing Our inverters are in the loft space but you walk into the space through a door on the first floor - it's a dormer bungalow. We also have friends whose inverters are in their loft but again, they have a staircase to rooms on the second floor. Installation is a grunt to get the kit upstairs but it does reduce the length of cable to PV and makes use of otherwise dead space.

Of course, getting the kit through a hatch in the ceiling would be a challenge!

One more vote for the linked garage: Ease of installation, ease of access to check the various monitoring LEDs, and much more stable temperature over the year.

We had the same choice and went garage. I put a max/min thermometer in the loft for a week, and it went well above the battery data sheet max temp range several times. So that pretty much decided for us. Add in the weight issues and ease of accessibility, and it was garage hands down.

Well thanks all for the input. I guess my other option is to put everything currently in the garage in the loft ..... 🤣

Our 5kwh battery went into the loft (installers were going to put the 8kwh up there but it never came back into stock). They didn't cause a fuss about getting it up there and we haven't had any problems with it (installed march 22). I'm not on top of monitoring the temperature, but I've never had to do anything with it with regards to cooling or resetting. So I wouldn't have any concerns recommending that too if the installers are happy to do it 😄

I have a 5kw gen 1 inverter in the loft with a 8.2kw battery, been there since end of August , no issues with temperatures, but just in case I have an eps socket ready to add a fan to if needed. Installers had no issue getting the battery in the loft , 2 guys in the loft some webbing straps through the battery handles and it went up no problem , with a little guidance from me as it went through the loft hatch.

I was planning to have my 8.2Kw put in the loft - cleared a space ad boarded it over ready. But when the guys came they said they couldn't get it up there even with a winch because of the position of the loft hatch relative to the beams of the roof. I have a "hipped" roof and there simply wasn't enough clearance between the top of the hatch ad the sloping roof beams. In the end mine was installed outside, and it is definitely easier to keep a eye on there. But, if I had had the choice I would have had it put in the garage, but unfortuately mine is a log way from the house. Go for the garage - protected from the elements - unlikely the temp will drop low enough to affect operation in the winter , and easy to check on if you have any issues.

Thanks all, useful feedback for me, and perhaps for the next person who has the same decision to make😊.

Had an inverter and 8.2 added in the loft in Sept so not seen the summer yet although I did have a thermometer up there in the summer and it didnt get close to the max temp in the documentation. The installer did say they had done plenty of installs in lofts and not to worry. I did ask about changing to a 9.5 battery but they said the extra weight of that over the 8.2 was too much and they couldnt put that in the loft despite a decent size hatch and boarded all the way through.
Unfortunately I don't have a garage so didn't have that option.

Tim Hi Tim!

I have the same setup as you, my inverter + battery are in the upstairs airing cupboard, typically where you may find a hot water tank but there isn't one there.

I've left the door slightly open recently as it can get pretty warm in there, and the door I have doesn't allow for any airflow in the space. Do you pay any mind to this factor?

I am simply thinking that in the height of summer when indoor temps are 25-30C anyway, adding the inverter + extra heat from solar generation could mean this gets too hot.

Mine (Gen 1 3.6kW, 2 x 2.6kWh) is in the loft, it worked fine during the heat waves, batteries got to 45 degrees peak and the inverter got to 73 degrees. Both batteries went into a deep sleep mode during the Dec cold snap, GE revived one remotely when I turned both on using the push button switches on them. The other one they're are sending an Engineer out to hopefully sort. They said that putting insulation on is fine, so I put some 200mm rock wool on when it got cold again in Jan and since it went above 0 on a night again I've taken the insulation off.

Out of interest, what is the maximum safe operating temperature for the inverters? I see that its up to 55 degrees environmental temperature but can't find a max temp for the unit itself.

TRBob 73 degrees is indeed toasty! I have to say in the summer the loft would likely be much warmer than my cupboard space would be, but there is more airflow in the loft.

I've had an 8.2 in the loft for a bit over a year now along with a hybrid 3.6 inverter. My installer was happy to put it up there, helped by the fact that I've boarded the middle of the loft from end to end so working up there was fairly easy.
The temperature is a minor issue, but as others have I've mitigated that with a combination of some USB PC-case type fans mounted atop the inverter to drag hot air out, and a floor-based fan circulating the air around both items running on a timer during the hottest part of the year. Looking back at an arbitrary date in August the inverter did report a max temp of just under 55 degrees in the evening. From looking at the time I suspect a combination of heat building up during the day and the battery outputting at full load.
Wifi can be spotty despite putting an extender on the landing but apart from a few teething troubles that now seems to be sorted and the kit has performed very reliably.

LordHippos Our airing cupboard is to the same level of insulation as the rest of the upstairs - 100mm kronospan slabs between rafters with roofing membrane under tiles under PV panels outside and plasterboard inside. I shut the door on the space when the two HY5 inverters and Batt8.2 batteries were installed in January last year but monitored the inverter temperatures.

In April when the inverters were often reaching 4kW output for several hours and the reported temperature was exceeding 55°C, I added PC-style fans underneath the inverter heatsinks, controlled by a DIY ESP8266-based temperature monitoring device that monitors temperature above and below the inverters and the void where air could be drawn into the space if I put a fan there. I set the fans to switch on when temperature reported by the inverter exceeds 40°C and switch off when it falls to less than 39°C.

By late May, with longer sunnier days and each inverter output exceeding 5kW for several hours (battery charging reduced to 1.5kW and house load to EV etc of 8kW and export of the surplus), the temperature above the inverters was exceeding 50°C, bearing in mind that outside ambient temperatures were in the high 20s. At that point, I added a bathroom extract fan directly above the inverters to extract the hot air to the loft space beyond the airing cupboard. Since then, as long as the DIY temperature monitoring system is working, we haven't exceeded 48°C as reported by the inverters.

One side-effect of this is that when off-peak charging the batteries overnight in December, the bathroom extract fan was cutting in and this could be heard in the bedroom. I reduced the charge rate so that the battery just reached the desired SoC at the end of the charge period and the fans don't cut in at all now.

Temperatures above and below the inverters are almost always less than the inverter temperature, suggesting that the volume of air in the cupboard is sufficient to support passive cooling with the door closed. It's only when there's lots of sun (or when charging at full power off-peak) that the PC fans cut in, and only when the inverters are pushing more than 2.5kW for more than a couple of hours is the extract fan needed.

There were a couple of occasions when I was working on the DIY temperature controller while there were high inverter temperatures and I opened the cupboard door and snaked a bathroom extract ducting into the far corner with a fan on to pull cooler air from the space outside the cupboard and blowing the warmer air out of the cupboard. This was not really very successful but the extract from directly above the inverters is working fine.

LordHippos I should have added, that was on the 19th of July when it was 40 something degrees outside.

Hi
I deliberately decided against putting my inverter and 9.5Kwh battery in the loft purely due to the high summer tmeps..
I have a temp monitor up there and it frequently goes into the 40oC range on a summer day.

Whislt the battery and inverted will work in this range, i'd be very concerned about the long term impact to the health of the battery cells and it causing premature deterioration. Temperature related degradation of LiPo4 cells is purely a chemistry thing and nothing against GE.

Added to issues with acesss, installation (both lifting up AND out when eventually needed) plus a (incredibly small) risk of fire, i insited on putting them outside, and happy to accept to lose some battery capacity when the cells are very cold.

Mine are mounted high up on the side wall (passage way) of my house so they are accessbile if needs be but don't block access for my bins etc. It took a team effort from the elecitrical team/roofers to lift them up, but still a lot easier then getting them up into my attic!

Garage - Hybrid and 2 x 8.2 batteries.
Easy to install, observe operation and stable temperatures.
Judging by my loft space, summer would be way too hot and winters way too colddddddd.

DIG If it doesn't get too cold in your loft in the winter your insulation is totally inadequate and you's probably save as much by adding insulation as you get by load shifting with the battery.

Tim Yeah this was my concern, essentially I'm either likely to need to keep the door open, add a door that includes vents for passive airflow (I guess a door may exist where it's got slats on or something) or do like you suggested, some kind of ventilation into the loft-space.

If I close the door I don't really see how the cupboard won't get too hot, between ambient temps, and the total lack of airflow, with a fair amount of generation in the day it will just turn it into a little bit of a sauna maybe.

Ideally I'd want something you can turn on or off depending on the conditions, probably don't need to worry too much currently.

Saying all of the above people do run these in lofts, and my loft gets incredibly warm in the summer, way warmer than this cupboard space would likely get.

LordHippos I suggest you close the door now and monitor the temperature to get a feel for whether the volume of air in there is sufficient to allow for passive cooling at this time of year. I'd also be planning to extract air from the cupboard if necessary. It'd be unfortunate to see really good PV generation but the the inverter shuts itself down because of high temperatures. The extracted air needn't go far, just out of the space and allow cooler air in from a different space.

Currently, our inverters are reporting 31°C (about 300W of PV each) and the batteries are 19°C. The space above the inverters is 21°C and the void below the floor where air would be drawn from through a cavity is 16°C and the outside temperature is 7°C. The cupboard door hasn't been opened in the last week. Yesterday was our best day so far this year for PV with a total of about 18kWh. The inverter temperatures reach 44°C just before midday but dropped to around 40°C due to the extra cooling over the heat sinks. The extract fan wasn't needed. In the summer, if it gets warm outside, the extract will probably be needed much more often.

I have 2 x 9.5's in the loft and a 5kw hybrid 🙂

Tim Door closed for now, it seals pretty well so there is functionally almost zero airflow in the space, only the bottom of the door may let a little ambient air in, otherwise I am entirely reliant on the space itself sort of acting like a big heatsink, the ambient air warming the plasterboard walls, and then those dissipating heat into the house.

I took a look at Heatsink temp via HA and it seems we get into the low 50's overnight when Go is charging solid for 3-4 hours.

During the day on a sunny day like today, with the door only just closed, we're hitting 46C or so, with the door no longer open I'd say that will get a bit higher.

My hive stats reckon ambient indoor temp is somewhere around 18.5C.

Temp data from HA (right click and open in new tab for bigger version).

My system (still doing the calibration of the battery), as only commissioned a few hours ago is in the loft. 5 kW Inverter with 2x5.2 kWh batteries. Originally was planning for 1x9.5 kWh, but installer thought that 2 x 5.2 will be better for manual handling purposes...it's not that easy raising 120 Kgs up to the loft. Wasn't easy either with the 5.2....

LordHippos I've done a plot of temperatures over a few days for one of our inverters and the probe in the space just above the inverters.

You can see that the temperature of the space above follows exactly the inverter internal temperature. You can also see at the top where the fans turn on above 40°C, usually as the PV array comes into full sunshine. I don't have data going back to last year as this is from Home Assistant history which only started a few weeks ago!

Tim My Inverter seems to run hotter than yours does in general. My lowest value is around 35C, maybe the residual heat from the Go charge which is currently set to 100% each night.

Yellow arrow where I closed the door today 🙂

As ironic as it sounds, and despite the fact this is where the inverter and the battery is, I have no plug in power source in the space lol! nearest power is from a socket I have in the loft a bit away from it, otherwise cable run across the hallway.

LordHippos did your installer wire up the EPS circuit? If not, a double socket off that could be used to run a fan.

https://kb.givenergy.cloud/article.php?id=12

They did not wire up anything EPS related so that is an option.

Today with the door closed the temps are certainly noticeably higher with the overnight charge, topping out at around 65C instead of the 55C or so I'd usually see, and dropping down to around 43-44C instead of the 36-37C I'd usually see it fall to with the door left open a bit.

Problem is that even a fan will just shunt warm air about the room, which is why I think better ventilation is somehow needed. Either via something like a bathroom extractor or the door itself simply having more a vent or some holes in or something to allow more airflow.

LordHippos I agree that it looks like the volume of air in the cupboard isn't sufficient to support passive cooling and that you need to allow warm air to flow out and cooler air in. Whether the air is naturally circulating or you put a fan on as well will probably depend on the time of year. How big a job would it be to put an extract duct to another room?

Tim

I have a pic of the location so you can see!

This backs onto my En-suite which is the left and rear walls of the cupboard space (Master bathroom shown and En-suite are next to eachother), that is tiled so that is a no go, in fact rear wall of the cupboard is the shower bit.

So I think my options are:

1. Ceiling mounted extractor fan that is capable of circulating air, ideally switching on only above a certain temp, or having smart control ability via HA. Above the cupboard is loft space with mountains of insulation.
2. Something above the doorframe. Would probably look a little ugly.
3. Door itself has holes punched into it and something added to allow air to breathe.
4. Wall to the right has something added, but I dislike that idea as it's more obvious than above the doorframe in 2) and also that wall has my boiler pipework for heating zones on it.

I haven't officially raised this with installer, but I must admit that in my naivety I didn't realise just how hot the inverter can run when it's processing a large power load.

I would probably go option 1, if you can find an extractor with a thermostat.

ToothyChris

For the most part that should work well.

In the summer that loft becomes real toasty though, so it will be unlikely to bring in cooler air, and not much cooler air to be found if ambient inside temp is 25-30C! For this time of year that would definitely work, but for summer I am less convinced still.

People must be running such systems though and even just having it sat in the loft it would seem it would get extremely toasty here in the summer.

LordHippos If you could run a flexible duct alongside your shower extract duct, you might be able to make use of the same route to your soffit, or wherever the shower vent exhausts to. If that's not feasible, then simple venting into the loft space won't do any harm since it is just warm dry air from within the living space, unlike the shower extract air. If the door isn't a tight fit, you could rely on the air being drawn under it, or cut say 5mm off the bottom if necessary. To keep the noise down, you can buy an in-line extract fan that fixes in the space above the ceiling. It's a pity there isn't a way to route the warm air to be used for space heating. We could have done that by exhausting into our bathroom which is below our cupboard but it was so hot last summer, that additional heat in the bathroom wasn't what we wanted! You might find it better to add small fans under the inverter cooling fins in the first instance. Our extract fan hasn't been needed since it was very hot last summer, the rest of the time, the additional forced cooling from a couple of 12V PC-style fans is sufficient for us.

LordHippos if a bathroom extractor was used, it would pump the hot air from the top of the cupboard, into the loft - not the other way round. Cooler air would then get sucked into the cupboard, around the door.

justpassing

Installer didn't want to install in loft due to access... smallish loft hatch and no boarding up there, along with weight of system... and the consumer unit is in the garage anyway. Temp swings would also be an issue, we've got only about 100mm of insulation up there and are planning on tripling that to at least 300 as soon as I am recovered from some surgery. I'm also going to board out a section around the hatch and maybe even widen the hatch to fit a proper fold out ladder.

ToothyChris Extremely minimal airflow as the door fit seems pretty good, which I think is also one of the problems!

I was wondering if an entire Louvre style door might do the trick:

https://www.wickes.co.uk/Products/Doors+Windows/Internal-Doors/Louvre-Doors/c/1000666

Or a louvre vent thingy but would need to be cut into the existing door:

https://www.screwfix.com/p/map-vent-fixed-louvre-vent-white-430-x-75mm/630hy

LordHippos Cutting 5mm off the bottom of the door would be the least visual distraction. If that wasn't enough then the vent fitted low down on the door could save the cost of a louvred door and disposing of your existing door.

justpassing
I put mine in the loft, it took some doing but has worked out well.
I have placed a number of computer fans around the inverter all controlled by a thermocouple .

Ours are in the loft (2x 8kW batteries and the invertor).
Sure was a good workout getting them up there - took 3 installers and me. The batteries are mounted to the wall in the loft and everything is boarded up there.
No issues I've noticed with the temperatures in the last year, I wonder if I can get back to the data from that 40c day...

Thanks All, thought I would post back and say the decision was easy. The installer wouldn't put it in the loft. So garage it is !

I have a 4kw solar invertor in the loft installed over 11 years ago and the givenergy AC3 + 2 x 9.5 batteries in the garage. If I could go back in time and advise myself I would have asked for the invertor to be in the Garage as well. During the summer the loft gets very hot and winter very cold. The garage temperature is much more stable and better for the batteries. To be fair the solar Invertor hasn't failed in all that time but no doubt in my mind that the garage would have been a better option.

My installer wanted to put the inverter in the loft but I insisted on it being in a cupboard with my other appliances (boiler, hybrid heat pump indoor unit). I installed a small vent at the top of the door. The house stays relatively cool in the summer, due to the house being well insulated, but the loft gets toasty hence why I wanted it in the cupboard.

NotoriousPyro What did you add? I am likely going to need to do something similar. My upstairs cupboard can get warm just from the warm air the inverter kicks out when the solar is strong or the overnight charge is ongoing. I leave the door open a bit currently.

LordHippos It's pretty much just a "MAP VENT FIXED LOUVRE VENT WHITE 229 X 76MM", you can get them from screwfix. I live in Scotland mind you, I don't have a battery hooked upand I've not tested it in summer yet, though the house being well insulated keeps it cool enough, as long as it has some way to vent the hot air somewhere (back into the house)... Heat rises so it should work in summer too AFAIK.

Atm the inverter gets to about 45c maximum.

Since they're only a couple of quid it might be an idea to try it before a more expensive option, though your cupboard looks quite small, you could always try leaving the door ever so slightly ajar and if it works then the vent would probably work as well.

If you need something with more oomph you could try "AC Infinity" ducted extractor fans, they come with a temp and humidity sensor.

I put mine in an old airing cupboard which used to house a hot water cylinder and now fits the inverter and 2 x 9.5kw batteries. I put a 75mm ventilation hole towards the top of the cupboard side and there is a slit air inlet under the door and so far the temp stays pretty stable around 20C. But only installed in mid Jan 2023. As a bonus, the airing cupboard is good for airing clothes as have put a few open slatted shelves well above the inverter and batteries.

NotoriousPyro Ah did you find my other post with the pics? Yes it's not a large space I'm working with. I have a similar bit above the door I could use though.

Battery itself doesn't really seem to generate heat but overnight charging via Go does, essentially with the inverter busy it kicks a fair bit of heat out.

What is the circular thing you have near the vent?

marklucey You've got a 75mm hole, have you put anything over it, or it is just cut through?

LordHippos Battery itself doesn't really seem to generate heat

When charging from solar at full chuff (2.5kW), the internal temperature in our batteries reaches the high 40°Cs, which is what I'd expect your battery to be seeing overnight on Go.!

This is a screen shot of the temperature in our cupboard above the two HY5 and Batt8.2s. You can see that the cupboard extract fan cut in on the 27th and 28th Feb, otherwise the volume of air is sufficient to dissipate the heat using the "PC-fans" mounted under the inverter heatsink.

LordHippos What is the circular thing you have near the vent?

Think that might be a smoke detector? We have a smoke/heat alarm in the airing cupboard linked to the rest of the house alarms, just in case.

Tim the internal temperature in our batteries reaches the high 40°Cs, which is what I'd expect your battery to be seeing overnight on Go.!

Is that for the batteries or inverter?

My batteries are in the garage, which is part of the house. Even charging at full pelt the batteries never go above 15C at the moment. High 40s seems very hot???

Tim When charging from solar at full chuff (2.5kW), the internal temperature in our batteries reaches the high 40°Cs, which is what I'd expect your battery to be seeing overnight on Go.!

Battery internal temp went from 24C at 00:30 - 31C by the time Go ended at 04:30 🙂

Your temp values are the above inverter ones rather than battery internal temp I think.

LordHippos one thing to note with mine is the bit above the door was just plasterboard one side and wood the other. If it's plasterboard or wood it would be easy to make a hole for the vent, I think even if you put it in the door it would make a difference, though not as much as if it were higher.

NotoriousPyro Yes it's just an internal plasterboard door, I can't imagine it's anything beyond plasterboard and wood, can't see there being any cables or anything either.

Zakalwe High 40s seems very hot???

Curious!

The GivTCP temperature that I have been using for monitoring is the "Battery_Temperature" seen above with history on the right. The individual temperatures for cells 1-4 are 10+­°C lower. From memory, the cells temperatures are from the space adjacent to those cells but where the "Battery_Temperature" value comes from, I don't know. If it came from the BMS circuit board it would make sense, but that's a guess.

@hoggy Any idea?

I'm pretty sure the 4 cell temperatures are 4 sensors within the battery pack and the one called 'battery temperature' is the BMS temperature.

My battery is in an attached garage ambient temperature 10 degrees last night. When charging at just over 2kW, the BMS peaked at about 15 degrees and the pack values were around 10 degrees, the inverter peaked around 35 but I do have cooling fans on it that come on and off automatically. 40 degrees seems very hot for this time of year.

4 Cell temps are (understandably) monitoring the cells at various spots (i think we deduced that some are on outer edges some deeper) from the readings.
The Battery Temp one I highly suspect is this one on the BMS board itself. Which will also likely be a bit higher than the cells even if they've been stood doing nothing as it's higher up in a fully sealed enclosure.

LordHippos The 75mm vent outlet has a plastic grill so it looks fairly good. Seems to work

Views from outside and inside cupboard. Seems to give enough airflow.

hoggy I had a web chat this afternoon and they agreed that the BMS temperature was likely to be high because of the environment. It looks like I need to monitor both the inverter temperature and the BMS temperature to trigger the exhaust fan. This is only really an issue this time of year. Later in the spring, I'll be able to reduce battery charge power as there will be sufficient PV around to fully charge the batteries slowly during the day. Today, I let them run free to ensure they were fully charged before the EV soaked up most of the surplus. Total generation today was allegedly 47.4kWh of which 14.5 went to Givenergy batteries and 19.4 went to EV; the surplus being exported. Not sure about the accuracy of these numbers though as one battery was down to 11% but the other was 38% although obviously efficiency was blighted by the BMS getting hot.

You can see from the power graph that it was a sunny day with lots of cloud getting in the way.

My BMS temp shoots up to almost 50 degrees as soon as 2.6kW is going through it. And that's with the ambient temp below 10 degrees.

Yes, I am worried. And yes, I've reported it... Struggling to get my message across.

(yellow line is BMS temp, green dots are garage temp)