Wiring multiple Nissan Leaf batteries with 2 Growatt inverters

[JayM]

I am finishing the design on my new solar project.

I've bought 2 Growatt SPF 3000TL LVM-48P all-in-ones with parallel kits from Ian at https://usa-mpp-solar.com/

I've bought 6 Nissan Leaf 48v Gen 2 modules with BMS from Fred at Tech Direct Club

I bought 24 Q-Plus 335w panels. Intention is 6 pairs in series to each inverter.

I bought the panel racking, solar feet for the metal roof, wiring, combiner boxes, etc. from Alt-e.

My questions are, with 2 inverters and 6 batteries, what's the optimal way to connect them? 3 batteries per inverter? All 6 in a bank?

If 3 in a bank, the other question: wire the batteries in parallel and then the positive on the first and the negative on the third to each inverter?

Common positive and negative bus bars?

Suggestions on fuses/breakers in this?

If it matters as relates to discharge, I will need to power a 15amp 220v AC well pump. Not constantly, but when water runs.

I am looking at the 4WG cables recommended on the @Will Prowse website for connecting them

Thanks for any input from a solar newb.

 

[Will Prowse]

The inverters need to be in parallel connection to a single bank. So connect all 6 batteries to both inverters.

Yes bus bars are ideal for multiple batteries. Ensure current rating can support your inverters max surge. Connect all batteries to bus bars, and bus bars to both inverters. Parallel everything. Probably best to run two sets of +/- bus bars. One for battery connections, and another set for paralleling the inverter. Then you can run a shunt between the two bus bars for your system.

OCPD figures can be found in growatt manual.

 

[tictag]

I bought 24 Q-Plus 335w panels. Intention is 6 pairs in series to each inverter.

Just checking, "6 pairs in series with a Solar Charger Controller", right? You can't connect PV panels directly to an off-grid inverter.

 

[Mac6792]

The inverters need to be in parallel connection to a single bank. So connect all 6 batteries to both inverters.

Yes bus bars are ideal for multiple batteries. Ensure current rating can support your inverters max surge. Connect all batteries to bus bars, and bus bars to both inverters. Parallel everything. Probably best to run two sets of +/- bus bars. One for battery connections, and another set for paralleling the inverter. Then you can run a shunt between the two bus bars for your system.

OCPD figures can be found in growatt manual.

I'm a little confused by what you wrote Will. Would he parallel connect the batteries to each other and then the pack to a POS & Neg bus bar? Then connect the inverter leads to those bus bars? - I haven't seen a situation where each battery was on the bus bar - If these were say 8 battleborns, would you parallel connect the two 48 volt packs to each other and then a bus bar or would you connect both packs to a bus bar?

 

[JayM]

Just checking, "6 pairs in series with a Solar Charger Controller", right? You can't connect PV panels directly to an off-grid inverter.

The Growatts are all-in-ones, charge controller, battery charger, and inverter. http://www.growatt-america.com/show-9-589.html

I apologize for the ambiguous use of 'inverter', because obviously you cannot wire PV directly to an inverter...unless it has a charge controller built in

 

[tictag]

Ah, yes, of course. Sorry, was obviously a bit tired yesterday!

 

[Wizardket]

I am planning a very similar setup using a Growatt 12000T. The BMS on the Leaf batteries from Tech Direct Club do not have a CAN buss. To what are you or do you set the charging settings. I was looking at chaining two or three of the Growatt SPF 3000TL now and adding more later if needed but cost wise the 12000T was better.

 

[cdunham]

I am finishing the design on my new solar project.

I've bought 2 Growatt SPF 3000TL LVM-48P all-in-ones with parallel kits from Ian at https://usa-mpp-solar.com/

I've bought 6 Nissan Leaf 48v Gen 2 modules with BMS from Fred at Tech Direct Club

I bought 24 Q-Plus 335w panels. Intention is 6 pairs in series to each inverter.

I bought the panel racking, solar feet for the metal roof, wiring, combiner boxes, etc. from Alt-e.

My questions are, with 2 inverters and 6 batteries, what's the optimal way to connect them? 3 batteries per inverter? All 6 in a bank?

If 3 in a bank, the other question: wire the batteries in parallel and then the positive on the first and the negative on the third to each inverter?

Common positive and negative bus bars?

Suggestions on fuses/breakers in this?

If it matters as relates to discharge, I will need to power a 15amp 220v AC well pump. Not constantly, but when water runs.

I am looking at the 4WG cables recommended on the @Will Prowse website for connecting them

Thanks for any input from a solar newb.

Hi Jay, do you have any pictures of your final setup? lesson's learned?

 

[cwilken]

The inverters need to be in parallel connection to a single bank. So connect all 6 batteries to both inverters.

Yes bus bars are ideal for multiple batteries. Ensure current rating can support your inverters max surge. Connect all batteries to bus bars, and bus bars to both inverters. Parallel everything. Probably best to run two sets of +/- bus bars. One for battery connections, and another set for paralleling the inverter. Then you can run a shunt between the two bus bars for your system.

What does the Shunt connect and do here?