Investing in a small GivEnergy battery to access Intelligent Flux

Screwdriva

pete-20-11 said:

An important note re battery capacity and charge/discharge rates...

A 2.6kWh givEnergy battery can only charge or discharge at 1.3 kW.

So if you turn on the kettle at 5pm you might end up pulling from the grid - eating into the profits.

A 5.2kWh battery will discharge at 2.6 kWh.

The AC3 inverter can discharge at 3 or 3.6kWh I think, but is limited by the battery in the above two cases.

If you get a battery that is bigger than the 5.2, then the limit will probably be the inverter at that point. 

Also note that the 2.6 kWh and 5.2 kWh batteries are not 100% depth of discharge. Some of the battery is reserved for health reasons. For example the 5.2 kWh battery is 4.1 kWh usable. Thus it will run out quicker. 

The 2.6 kWh is probably around 2.1 kWh usable. 

Plus is the difference in battery cost worth it - if you've got to get an accredited electrician in to install the battery and inverter, that will be a lot of the cost. Going for a slightly larger battery maybe worth it. 

Similar to the concept of solar panels - when you've got to pay for scaffolding you may as well get as many panels on the roof as you can. E.g. panels are cheap, scaffolding and install costs aren't. 

Very valid. My primary goal is maximizing export revenue. We don't use much electricity during the 4-7pm window (telly, lights and the odd appliance). All our heavy appliances run between 2-5am. 

The difference in cost between the 2.6kW and 5.2 kW is <£500 so you may have a point there.

pete-20-11

I've just noticed I'd got some of my units mixed up. I've corrected the original post. I blame the heat! 🤣

Battery size in kWh, discharge and charge in kW. 

I'm sure we both knew that, but typos happen! 🤣