Charge efficiency of Multiplus 24/800/16

[thanar (Thanos Tourtouras)]

Hi.

I am testing a Multiplus 24/800/16 as part of a Dynamic ESS installation, lithium battery. As I understand from the unit’s technical specifications, it can output a maximum sustained rate of 16A toward the DC bus. However, it’s been almost half an hour now that power draw from the grid has been stuck to over 530W, which translates to over 19Amps going into the DC bus.

Am I missing something regarding the charge capacity of this inverter/charger, or are the extra 3A calculated charging losses into the unit? If it’s the later, that would calculate up to almost 20% of charging losses.

So, I did a test by disabling all Solar input, and indeed it does seems like a total of 433W is exiting the Multiplus… Which does indeed calculate down to 81.5% efficiency, with 94% advertised on the spec sheet, although that one is the inverter efficiency. Isn’t that a bit on the low side?

Which now leads to the next question: Are these losses being taken into account by the Dynamic ESS scheduler? 20% charging loss is quite a lot imho.

[MichelleKonzack]

My MultiPlus-II 24/5000/120 has also charged several times with 127A for what reason ever without breaking or thermal shutdown.

Simply take it as it is.

If you do not like it, you can reduce the charging current in the Configurator.

[thanar (Thanos Tourtouras)]

Seems like it’s charging at it’s theoretical maximum of 16A on my case; the rest of its consumption looks like it’s losses. Almost 20% of charging losses.

[josec]

My 3000va 48v takes 2000w from the grid to put 1700 on the battery approx.. 15% losses, is really too much, I rarely charge the batteries with grid power but I do not expect this loses margins when I calculate my consumption numbers when mounting the system. Also you need to add more loses to use the energy from the battery, so total loses are nearly 20% !!