I'm interested in utilizing the SMA Sunny Boy Storage inverter for a battery bank. I understand that for example the LG Resu HV battery is actually a 48v bank with a DC-DC boost converter that is outputting 400v. I'm assuming that this converter is a bidirectional converter, which would then allow for charging of the batteries. The only one I have been able to find is THIS one. At about $4000 per 2Kw, that's a very expensive proposition. I rather like the idea of building a 48v pack and then boosting the voltage, as it seems inherently safer to deal with, but perhaps the only option for DIY is to actually build a HV pack and then use Batrium, REC, Emus or some other BMS capable of dealing with higher voltage. I haven't been able to find any examples of people using this inverter with anything other than a commercially available battery pack.. perhaps someone knows of such an integration.