Design Check/Options for parts?

[harjms]

I have 3 DIY battery boxes on order from Luyuan. Amy was able to tailor some custom options (added the fire suppression packs and color option) for me and should be here in the next couple of months. The DIY battery boxes will come with the busbars, nuts, etc... I also ordered JK BMS 200A for each battery pack from Amy as well. The 48 MB31 cells should arrive at the seaport in early July.

I've ordered and received Blue Sea Class T Fuse holder, 250A fuses, and 1000A busbar.

I plan to install 4/0 AWG cable from the inverter to the busbar. I will also install 1 or 2 AWG (not sure yet) from each battery to the busbar.

The problem I have identifying is a momentary push on/off switch for a pre charge circuit and also a 52+ VDC rated switch to isolate the battery bank from the inverter; I'm not looking for circuit protection as I will use the Midnite breaker for that, but just wanted something in between so I can use the pre charge circuit when needed.

Any issues with the design below? I plan to install the bus bars, shunt, charge circuit into a NEMA type enclosure to keep it nice and neat.

Any suggestions on the additional parts (on/off switch, momentary switch)?

 

[harjms]

Cells should be arriving to port early July then FedEx to the East coast once it's released. DIY boxes from Luyuan have been completed and are being shipped out soon.

With that being said, anyone have any inputs for the above? Do I need a fuse between the positive busbar and inverter? If so, what amp fuse do people recommend?

Any recommendations on sourcing of cable? Looking for 2AWG and 4/0AWG welding cable, but not sure where's the best prices are found.

Thanks!

 

[chrisski]

Do I need a fuse between the positive busbar and inverter? If so, what amp fuse do people recommend?

In the original post yoy mentioned a breaker. If that’s true, a fuse is unnecessary.

What is the temp rating if the 4/0 wire and the inverter wattage and concern it’s 48 volts.

I want to say 200 or 250 amps, but wire ampacity is importantly and also making enough current for the inverter.

The problem I have identifying is a momentary push on/off switch for a pre charge circuit and also a 52+ VDC rated switch to isolate the battery bank from the inverter

I used this resource to build a pre charge resistor:

Inverter Disconnect Switch with Precharge

Jun 4, 2020

Inverter Disconnect with Precharge

• FilterGuy
• Inverter's

 

[HRTKD]

The Victron Battery Switch is one of the few switches that is rated for 48v systems. I'm using it in my system.

I'm using a 48v light bulb for my pre-charge circuit. It works, but it's necessary to have EVERYTHING disconnected except for the inverter.

The vendor I bought my equipment from showed me how to use the solar charge controller to pre-charge the inverter. Of course, that only works if you have enough sunshine.