Battery 48V into inverter MPPT input Possible?

Hi,

I am trying to use my battery to cover some of the afternoon electricity usage. I am thinking about doing a DC coupled battery bank etc.

Currently I have a SP2000 Growatt with 5kw of battery. it kinda working at the moment and cover some of my afternoon at peak. I have a second 5kw battery and hooked up with a BMS etc.

What I want to do is for the battery to discharge in forms of lets say 120v @10A to the SP2000 via the Panel MPPT input are. How to up the 48V into lets say 120V at 10A ?

Thanks

Why not just feed it into an inverter covering some loads? Better and more efficient and legal.

Just use an ats to switch between the inverter and the grid

I need to battery to discharge around 4pm onwards.

48v is not high enough to wake up the inverter, in fact I use a DC DC controller to boost voltage to 76V but inverter still doesn't wake up.

Can you parallel the batteries? might be next to impossible with the SP2000 being a smart battery and would void your warranty. even feeding into the battery bank via the solar mppt inputs with the other battery might be enough to void your warranty. I assume it is fairly new?
Later floyd

Technically it is possible by center tapping the battery and haveing two boost converters in series from a center tap, but very stronly recomend you dont do it. There are other issues with how youend up with voltages between places you would not expect. Dont do it.

I have achieved this when testing and started up an inverter with 150V (from 48V source) but this was very much at arms length and in a way which I never used because it creates a situation than makes the wiring unsafe as a whole. Again, don't do it.

Second and most importantly, based on what you have said and the question your asking, I'm guessing (99% certain) you system is on a feed-in tariff. IF you feed a separate DC power source into the MPPT input this invalidates the feed-in-tariff payment and opens you up to having your payments recovered. The data is half hourly so the DC feed-in would stand out very obviously if you fed too much in or at the wrong time.

Lastly, 120V DC will kill if you have an accident.