Can an Off Grid Solar Inverter be powered by batteries in the PV input?

[cs1234]

If I ever get the truck (they had no idea it was going to be so popular) , I'll make a thread on doing it.

I imagine they are simply production limited based on some part(s) needed from China.

 

[timselectric]

I imagine they are simply production limited based on some part(s) needed from China.

That's part of the current situation. But originally, they just couldn't make enough. Currently building more assembly plants. I'll be lucky to get a 2023 model.

 

[cs1234]

That's part of the current situation. But originally, they just couldn't make enough. Currently building more assembly plants. I'll be lucky to get a 2023 model.

Maybe they will have worked out any kinks by then, works out in @timselectric favor!

 

[Yuri.]

Since you guys look curious, here is why I'm asking this. I'm thinking on adapting a Ford Transit as a RV, diesel powered, with about 20kw.h of power storage, here is my ideas so far, if this ever happens it will be a long time in the future
1) Get a Ford e-transit and directly hook the solar inverter in the battery for AC power.
2) Get a Ford e-transit and avoid messing with the power delivery directly, but that would require:
A smaller battery of about 5kw.h and configure it to be automatically charged using the 2.4kW AC power the e-transit have available from factory. My peak power would be 5.5kW peak only, averaging 2.4kW would totally work. But this would require some shitty AC-DCs and DCs-ACs back and forth and a lot of power lost doing it.

3) The most likely one due to cost. Since the fucking e-transit is like 65 thousands euros at the largest size. I can get an used Diesel one for like 30k instead. And I would make a battery setup with around 20kW.h and just charge it as necessary using the CHAdeMo connector which the orion 2 works with. Likely when I decide to do this there will be some open BMS compatible with CCS which is much better, but for now that doesn't exist.

In all cases I would make the van totally electric, except for the drivetrain, including an induction cooktop.

 

[timselectric]

I looked into the Etransit , but the range isn't enough for me. I have customers who are close to a hundred miles away. And no CCS's in between.

 

[Yuri.]

I looked into the Etransit , but the range isn't enough for me. I have customers who are close to a hundred miles away. And no CCS's in between.

It would for me. It would just be used to move small distances, I'm thinking about living in it.
Too expensive though, but maybe...

 

[cs1234]

I really wish they would bring out a plug in hybrid work van here in the states. I would switch my fleet over to them and be overjoyed.

 

[timselectric]

I am actually thinking of installing charging stations for my long distance customers, at my expense. They would pay for themselves in no time. And if I install them for free, they'll never charge me for using them. ?

 

[phx]

Because solar panels are current limited and batteries can give up all their energy in an instant.
Please report back afterword.

MPPT is designed to squeeze out the maximum possible DC power from the DC source (PV modules) with a large fluctuation of output voltage. The MPPT would draw as much current as possible to achieve the biggest power output. Hence it will try to get the maximum power from the battery, which it's capable of providing each moment. Compared with the car battery operation, it would be a constant "Crank mode" of the starter.

On the other side, each inverter is limited by its nominal power. If it tries to process more DC power than it's designed, it will have a "plateau" where the AC output wouldn't further grow. E.g., like, in the situation with a 10kW solar array connected to the 5kW inverter.

Hence the MPPT inverter would work safely with batteries only on one condition: the battery should be able to provide the entire nominal power of the inverter for all the time of operation of such a system. E.g. for a 5kW inverter, the battery should be able to give out AT LEAST 5kw of power constantly during its entire time of operation. In such a case, the inverter would constantly operate in a 5kW "Plateau mode," and those 5kW would be constantly drawn from the battery (regardless of its depletion) and converted to the 5kW AC (minus efficiency factor) on the inverter output.

That would be true for grid-tied inverters. For off-grid - the power output (and the DC input) would be dictated by the AC load.

There are some inverters (e.g. Sunny Boy SMA-5000) allowing to choose of MPPT vs. non-MPPT mode for the DC. They are certified for DC sources with content voltage (like batteries), however, the batteries are not mentioned directly.