On-grid domestic battery storage

joefizz

Increase the base load on the battery until the generation is high enough and turn it off.
or.

Instruct the battery to charge from the mains


Probably neither of which will make much difference though. Ive done part 1 above for much of this week by accident rather than design! Part 2 will probably mean you end up drawing power in at some point...
...but then what if you had 2 batteries ;-) - only kidding ;-)

mmmmikey

joefizz wrote: »

Increase the base load on the battery until the generation is high enough and turn it off.
or.

Instruct the battery to charge from the mains


Probably neither of which will make much difference though. Ive done part 1 above for much of this week by accident rather than design! Part 2 will probably mean you end up drawing power in at some point...
...but then what if you had 2 batteries ;-) - only kidding ;-)

Thanks - the second of these options is worth playing with, I could put it on to force charge and then switch it off again and see if it keeps charging from solar. None of this is going to make a huge difference, but every little helps.


As far as adding a second battery is concerned, I think I'd need a Jacuzzi as well to make it worth it as I don't use enough power otherwise

joefizz

mmmmikey wrote: »

As far as adding a second battery is concerned, I think I'd need a Jacuzzi as well to make it worth it as I don't use enough power otherwise

I think they sell off the inflatable hot tubs for around 250 quid this time of year ;-)
I do recommend the infra red saunas though. Id always thought Id be using it during the winter, not late august/early september!


I need to crack on soon with the backup/off grid modifications which might get around all of that so if I get anything other than blood loss, soft tissue damage and lots of swearing I'll report back. ;-)

mmmmikey

joefizz wrote: »

I need to crack on soon with the backup/off grid modifications which might get around all of that so if I get anything other than blood loss, soft tissue damage and lots of swearing I'll report back. ;-)

Yes, let us know how you get on with that.



I'm at the early planning stage for a decent battery system for a caravan for an extended tour next year. I'm thinking of something that I can use at home when not touring - maybe 1kWh or so with an inverter big enough to drive lights, TV, broadband and rainwater pump. My bungalow is wired so that I could easily have a completely separate circuit for low power essential items. The idea is to alternate between sites with and without mains hook-up when touring and charge the battery when at sites with mains, which is similar in use pattern to a mains backup/UPS type solution. Any thoughts?

joefizz

mmmmikey wrote: »

Yes, let us know how you get on with that.



I'm at the early planning stage for a decent battery system for a caravan for an extended tour next year. I'm thinking of something that I can use at home when not touring - maybe 1kWh or so with an inverter big enough to drive lights, TV, broadband and rainwater pump. My bungalow is wired so that I could easily have a completely separate circuit for low power essential items. The idea is to alternate between sites with and without mains hook-up when touring and charge the battery when at sites with mains, which is similar in use pattern to a mains backup/UPS type solution. Any thoughts?

Pretty much what I am doing with the campervan. At the minute it doesnt have a leisure battery but rather two full size starting batteries which arent split charged but do also run off the zig charger in the back. Ive an old 300w inverter for it but its not pure sine wave so some of the latest stuff I have wont recognise it (old laptop will), so it all needs changed. I dont have solar with it so was going to go with a 100w panel for the roof (its a swb transit) and still havent made up my mind if Im going to go flexible or rigid. Its been off the road 2 years now so I need to get round to it soon as I missed it this year.
So similar idea when its sorted, part of the garage roof is transparent so there will be losses but essentially it will be a battery bank just sitting there when its not used and along with both 12v and 240 output could be used in a power cut to mimic mains (having isolated my house of course). I have a separate spur off the mains input feeding a consumer unit in the shed/studio and one off that feeding the garage circuits so its possible to use all that to feed isolated circuits in the house (or easy to put in with timber framed bungalow). All connected up to the house solar and battery.
Of course Id need a load to dump the excess solar to in that scenario but thats where an iboost/immersion comes in.


Currently I also have a 12v circuit in the garage. I have the boat leisure and starter batteries both under the bench in the garage connected independently to separate 20w panels and regulators. At the minute purely to keep them topped up when Im away. I also have smaller 10w panels to connect to the other cars when the batteries are in situ in them for periods. I think I have about 2-3 of those panels as well. The two 20w panels at the minute arent connected to anything and arent really used other than occassionally using them to power leds above the garage workbench or use their 5v out usb lines for phone charging etc etc. Thats a bit of a wasted resource and could be utilised so first stage is to extend the 12v circuit to the garden (if length permits, might need to move some of it around) to set up a remote controlled led lighting system for the garden. Currently there are lots of different types of small solar things (ikea type running off single rechargeable aa) but as the batteries die in those they are being cut up to feed into the lighting system. Ive a bagfull of already set up for 12v leds for various car/boat/campervan projects so no reason why they cant be used in the house for lighting/emergency lighting and run that off the lead acids. The lead acid circuit will also have a smart charger feed to the main house as well (confused yet?!) and so adding the zig circuit from the camper as well will have at least 4 lead acid batteries capable of connecting. Thats more than enough to run the stuff you talked about, and if I can set it up right, enough to enable me to run the solar panels and batteries off grid if needs be. (if I cant just reset the solaredge inverter to run in off grid mode with a toggle switch - dont do this at home kids ;-))
I stripped down and rebuilt my house a couple of years ago and in a few of the rooms (bedroom, living room, kitchen) I have put in remote controlled 12v led strip lighting, the multi coloured, effects type accent stuff. Each of those goes to a 12v mains powered transformer in the loft with sockets taken off the various lighting circuits, the plan was at some point to extend the 12v circuit to feed those but this was before I got solar and the battery system for it which made that idea redundant.
I did think about putting a 240v socket in each room fed to one separate circuit which could then be 12v inverter fed but from a wiring and safety point of view it would be a nightmare for anyone other than me ;-) Not planning to move so Id probably be dead by the time I kill someone else ;-) The battery has since made that idea redundant with the ups feed from the battery going back into the house circuit with a physical switch but no reason why whereever the garage feed/external wall socket from the caravan/camper couldnt just go to a circuit you isolate at the junction box. In the past during power cuts Ive connected a generator to the garden wall outlet which is connected to the kitchen ring main and Ive isolated that at the consumer unit so the generator is just driving the kitchen. The kitchen circuit has the heating/boiler controls fridge etc so its all I really needed, my ISP no longer seems to have 24 hour battery backup in the street cabinets any more so when the electricity goes out so does the hard line broadband!



I probably only will ever need say a 500w inverter for the camper which probably means getting a 1000w one for peaks etc which probably means a 1.5k cheap one ;-) Thats the one bit of kit I wont skimp on or cobble together in the whole setup so need to do more research into that because the good brands now internally look no different to the cheap chinese versions. One thing I have planned though is to make all of the components easily accessible in the builds so they can be swapped out in the future.

Reed_Richards

I asked the manufacturer of my inverter if it could be set to charge the battery from the mains at a scheduled time. Actually this is hypothetical for me since I don't have an Economy 7 meter or similar. But the response came back that it would be illegal to do this. I queried this and am waiting for a response. The only thing I know of that I believe would be illegal is to charge the battery from the mains, then discharge it back to the grid later and claim that was part of your generation for the FIT payment.

mmmmikey

joefizz wrote: »

Pretty much what I am doing with the campervan.

Thanks, some interesting food for thought there - will give it some more thought and let you know what I end up doing.

mmmmikey

Reed_Richards wrote: »

I asked the manufacturer of my inverter if it could be set to charge the battery from the mains at a scheduled time. Actually this is hypothetical for me since I don't have an Economy 7 meter or similar. But the response came back that it would be illegal to do this. I queried this and am waiting for a response. The only thing I know of that I believe would be illegal is to charge the battery from the mains, then discharge it back to the grid later and claim that was part of your generation for the FIT payment.

Interesting, I can only think the inverter manufacturer didn't understand what you were asking as cheap rate charging from the mains is standard functionality on many inverters and certainly not illegal. The likes of Victron (and many others) even make specific inverter-chargers. As you say, if you use that ability to some how fiddle your FIT payments that would be unlawful but that's a different issue.


EDIT as an afterthought if you connect a battery system on the DC side (i.e. before your generation meter) then simply charging the batteries from the mains (assuming your inverter allows this) would potentially effect your FIT payments, but you can perfectly legally get round this by installing a 2 way generation meter and notifying your FIT licensee - maybe this is what has confused the manufacturer?

Reed_Richards

mmmmikey wrote: »

... but you can perfectly legally get round this by installing a 2 way generation meter and notifying your FIT licensee - maybe this is what has confused the manufacturer?

I have always had a 2 way generation meter; I didn't know there was another sort.

ASavvyBuyer

This may be of interest to those with or considering getting an EV.

https://www.speakev.com/threads/ovo-v2g-trial-update.143316/