Adding a second GivEnergy battery

I want to add a second GivEnergy battery to my 'plant', which comprises 14 390W Trina solar panels a single inverter and a GivEnergy 5kW (Hy5) battery.

I'm finding that my system is generating way more electricity than we use, particularly on sunny days, but we quite often end up using all of the available energy in the battery overnight.

I'd like to add a second battery and would like to know if anyone else in this community has done this. If so how does the system need to be configured, who did you use for installation, how doe multiple batteries manifest on the GivEnergy App.

Thanks
Adrian

AdrianBall65 it simply appears as a bigger battery. Whilst you may be exporting at the moment, ensure that you need and can use the extra capacity throughout the year. What size battery do you currently have and will you be able to charge a larger battery fully in off-peak hours?

Yes another battery can be added by an engineer. As the system needs updating and recommissioning with the extra capacity.

AdrianBall65 quite often end up using all of the available energy

@stevelewis has a point about ensuring that it's worth increasing your battery capacity. However, if you are already running out with generation late into the evening or from early morning, then another battery might work. We have two HY5, each with an 8.2kWh battery and this time of year we are using maybe 30% of capacity overnight. Earlier in the year, we were waking up to 50% SoC or less. This is because dark hours were longer consuming more from battery although the shorter solar charge window and the lower sun meant that full charge often took to the end of the afternoon.

A second battery could work out for you but there will come a time when you'll be struggling to completely charge your existing battery from PV. You could look at an off-peak electricity tariff (especially if you have an EV) to boost your batteries overnight.

I must admit that we got caught out by the battery supply difficulties I think, the supplier insisted that a 5.2kWh battery would be ok, and in the main it isn't too bad, daily usage from the grid is under 2kWh at the moment.

I have considered another battery but I'm not sure that is cost effective, I need to see what it looks like after a year. As far as I've seen they can't be 'cycled' so that Fully charged to fully discharged takes precedence i.e Bat A & B are charged, Bat A provides until empty, then B takes over and Bat A charges when there is a surplus Bat B is used until it is empty and then Bat A takes over etc.

SilverArt can't be 'cycled'

That's my understanding too for a multi-battery single inverter plant. The Battery Management System is designed so that batteries of different capacities charge and discharge pro-rata so that they both get to fully charged and fully discharged at the same time. This does mean that having a 5.2+8.2 would look to the inverter like a single 13.4kWh battery.

SilverArt If you connect 2nd battery and its bigger capacity then first make sure that bigger is set as master and its first in string and smaller its 2nd in string.

Worth a note as battery capacity on charger goes higher surplus is needed for longer. I have 21kw of panels and 16.4kwh of batteries currently on the set up via one ac charger but with peak charge rate of just under 3kw it takes 6 hours to charge the pack up. I'm in the process of installing another 19kwh of batteries (wifi dongle supply issues mean it cant be commissioned) but have put them on two new AC chargers, so I can effectively between the 3 AC chargers charge the pack in 6 hours still if I have 9kw of surplus for that time, if i had added them on the existing charger I would need surplus for 13 hours, which just doesn't happen most of the year.

ianhorton

Interested to see the stability of 3 x AC3s

Have a single 3.6hybrid and 2x 8.2kw batteries. The system has been working perfectly, bar a few minor hickups. We heat water, dishwasher, washer, etc by solar in the day, surplus going to battery for evening/night. Last two months have only drawn 2kw of daytime electric (economy 7) and average of 15kw nightime. The nightime was topup, for daytime use, to allow for two periods of 3days poor solar energy.
We are a heavy usage household, but this configuration works for the majority of the year. From November through to March we switch to everything reset for night usage and batteries charged on cheap rate for daytime use. We still required approx 60kw daytime in Jan and 30kw in February.

When we had the system installed it didn't make financial sense to have a third battery to cover this additional requirement. It would only be of any use for about 4months a year, charging overnight to ensure full daytime supply. The rest of the year it would just fill with the surplus solar, but we would have no use for it! The two 8.2 batteries was the way to go for us, allowing that extra capacity that also means you don't have to micro manage your system as much.

I am tied in to a good economy 7 rate till next September, but will have to re-evaluate the situation once I know what my future rates are likely to be.

I would have no hesitation adding the second battery, as others have said it just appears as one 16.4kw battery on the apps and they both charge/discharge in unison.