external battery enclosure

[Mr Gus]

If I recall correctly the main supplier of naff fibreglass utility meter cupboards also does more industrial ones, as the expect to see in engineering design, but I'd say that area of wall is suitable would be my start point for recessed wall mounted lockable secure, outdoor cabinet housing.


Govt Really needs to get its sh1t together where this sort of thing is concerned.

[Countrypaul]

Would there be any chance of going down and placing the batteries under the floor? Obviously I have no idea of the house construction, or ground/water levels so this maybe completely unfeasible.

[Mr Gus]

https://www.exponentialpower.com/produc ... sures.html

Sticking that link as a basis for a pre-existing enclosure mock up visualisation, if fan is needed = +3 inches on all sides.

[Oldgreybeard]

Should be easy enough to knock up a slim line box on the wall to house the batteries, I'd have thought. Probably better to just knock something up from scratch than try and find and adapt some other enclosure. Perhaps start off by fixing a sheet of marine ply to the wall, then making up sides and a front door, perhaps best made as a removable front panel. Suitably painted to match the house, perhaps with a bit of roofing felt over a sloped top panel to keep the rain out, and it shouldn't look too out of place. I have a feeling someone over on the "other place" did something like this, fit some electrical stuff in a wall-mounted home made outdoor cupboard.

I've found that the batteries don't seem to get warm from use, ours are in an unheated outbuilding and they stay a few degrees warmer than ambient all year around. I was worried that they would get too cold in winter, but the coldest I've seen them was about 8°C, when it was sub-zero outside. It seems they have a substantial thermal mass, and that, together with the heat given off from the inverter, is enough to keep them warm during cold winter nights.

Might be an idea to put some insulation in the enclosure, perhaps, just to stop them getting too cold in winter.

[Stinsy]

The battery needs to be very close to the inverter. So moving both to the attic would be the first choice. I’ve seen plenty of installs where the batteries/inverter are housed in an outdoor lean-to enclosure. However the charge rate of the batteries drops when they get too cold so outdoors would really only be if there was no other choice.

Yes I understand the battery needs to be close, I thought this was because of I2R losses at the lower voltage.

When it is cold the PV will not be producing much.

The vast majority of people with batteries use them not-only to store solar-generated electric but also to store cheap-rate electric. Mine are in the attic and in the coldest weather the BMS specifies a max charge-rate of 5A per battery instead of 25A normally.

You’re right, you should keep the battery cables as short as possible because the lower voltage requires much thicker cables to keep the power losses and Mable temperature under control. As distance increases the cables soon become impractical. Therefore if you’re moving the batteries you should also move the inverter.

[Oldgreybeard]

Just knocked up a rough sketch for a fairly simple outdoor cupboard, made from 145mm x 45mm treated timber (from any DIY shed) and some 19mm marine ply. Might give some ideas as to how a fairly slimline battery enclosure might be made to hold three US3000C batteries.

Battery enclosure.JPG (35.34 KiB) Viewed 1919 times

[Mr Gus]

Old Freecycle non freezer compartment fridge with a lock & some protective paint as an insulated option for bodgineering, ...we convert for cold smoking food, pull the compressor out & play around with it maybe? (..option for a metal carcass with insulation already present)

Responsible disposal of gases, naturally.

[openspaceman]

Thanks for all the input, I think OGBs graphic looks like the most practical solution, even I would be able to make that.

[Oldgreybeard]

Thanks for all the input, I think OGBs graphic looks like the most practical solution, even I would be able to make that.

Here's a couple of basic cutting lists for that enclosure. They need double checking, as I just lifted them straight out of the CAD model and bevels will need to be cut/planed to the edges of the rear, front and roof panels. I'd be inclined to just screw the front panel on and make the roof hinged for access to the cables and the battery pack switches:

Plywood cutting list.JPG (40.26 KiB) Viewed 1895 times

Treated timber cutting list.JPG (35.07 KiB) Viewed 1895 times

[openspaceman]

Thanks again but wouldn't a fixed roof and maybe a bit more height for hands be easier to weather proof?