Adding a second EP12
I had a single EP12 + 5KW H1 gen2 inverter installed 6 months ago.
This is big enough to run the house in the summer on off-peak electricity (no solar, UK, Octopus Intelligent Go tarrif).

I'm thinking about getting a couple of split AC units fitted, and we have an ASHP.
The second battery would therefore get used pretty much all year round, and make financial sense.

Existing battery is in the integral garage, and there isn't enough space left to sit another EP12 against the wall on the floor.
I guess the choices are:

Fit the second battery directly in front of the first one
Fit the second battery outside, on the other side of the garage wall.

The outside space is the the path down the side of my house, and is north-facing. Quite well sheltered by the eaves overhang (bungalow). The heatpump is on the same wall, but further along. In Cornwall, so very rare for the outside temperature to drop below zero degrees.

Would either/both be acceptable locations?
Re: Adding a second EP12
It’s not recommended to fit the second in front of the first, Fox want 300mm space around the battery for effective cooling, but the most important reason is that it needs to be fitted to a bracket on the wall, weighing nearly 100kg if it topples it will cause serious damage.

If you can produce a bracket mounted to the wall that can safely hold the battery upright whilst being 300 out from the first, maybe consider it.

On the outside wall, assuming cable lengths wouldn’t be too long (less than 3 meters), and the battery is shielded from direct rain and sun that is your better option - again it might make sense to put a canopy over it or a protective box to keep the worst of the weather from it, and ideally offer some insulated protection from the coldest days.
Re: Adding a second EP12
Thanks.

I've had a closer look at the outside space, and putting the battery outside would mean removing a shed and widening the path, so a fair amount of work.

We could relocate the washing machine and tumble dryer from the side wall to the back wall of the garage, freeing up enough wall space to mount the extra battery.
The two batteries would then be either side of the water cylinder and all the heatpump plumbing/controls.

How long are the DC and data cables that come with the EP12?
If they are short, are longer cables available?
Re: Adding a second EP12
The supplied cables are both 3 metres long, you will need a Fox EP junction box if you haven’t already got one fitted - all battery DC cables go from the batteries to the junction box and the junction box is cabled to the inverter; that cable has to be kept short (600mm)
Re: Adding a second EP12
That should work then. The gap between the batteries would be 1.85 metres, so 3 metres would allow for one battery width and a bend radius.

The inverter is at eye level, directly above the existing battery. Space for the junction box just below the inverter.

All I need now is a fair price for the job.
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