New 10kw NHX AIO From Watts247

[mciholas]

I want and need battery comms, that's why my BMS's talk to Solar Assistant.

Point me to a thread on how to have the SA box interface to both the inverter and the battery bank. That sounds like a great setup.

I'm warming up to the idea the batteries comms can be not tied to the inverter but monitoring by SOMETHING seems important. If SA can do that, then that's a win.

For ~$4000 with shipping and BMS's you can get ~31kWh and build your own that are easily serviceable.

Building your own battery bank from individual cells seems foolish these days. Even with free labor, you can't really achieve a better cost than what you can buy.

Haha, lots. Mainly keeping the 12V packs in balance, not being able to service them and not being able to monitor cells.

On balancing:

The battery maker says 4 in series (48V V) is okay, and if they are slowly top charged, that should keep them in balance. When the lowest capacity battery BMS trips out, the entire series string goes away, which then means every battery in the string had the same AH usage at that moment. Then the can all recharge back to full with the same AH put back in. Still, I get the point and it is better not to put these things in series if you can avoid it.

On servicing:

I don't see any difference between a rack mount and the big brick style. A bad cell and the whole thing is busted. If you put in a replacement cell (which would be a chore for either type), it is of a different age, capacity, etc, so balancing will be off. The "servicing" of the batteries is replacing a unit entirely.

The rack mounts at 48V are better in this regard since they are full voltage and thus you don't break up a string.

For both of the above concerns, there are 48V 100 AH versions:

Amazon.com

$978, so similar in price. Now each one can balance all the cells in series internally. Another advantage is that you can size your system in 5 KWH chunks, not in 20 KWH chunks.

On monitoring:

Yes, they have no SA or other logging style interface, so you lose that. They do have BT with an app, and you can use that to check for faults and other issues, but it isn't an appropriate logging style interface like one that would work well with SA.

Regardless what we choose all that matters is we are happy with our system.

That's what matters.

I'm very excited about what one can do with solar these days. A prime factor in that is how you can drive the cost down which is key to wider adoption, which also means lower costs for everybody.

Mike C.

 

[42OhmsPA]

Point me to a thread on how to have the SA box interface to both the inverter and the battery bank. That sounds like a great setup.

Pretty simple, just use a USB cable to connect your BMS(s) a to Pi running SA, a USB hub comes in handy when you have multiple packs. Then connect your AIO with another cable or wireless if supported.

Post in thread 'New 10kw NHX AIO From Watts247' https://diysolarforum.com/threads/new-10kw-nhx-aio-from-watts247.76813/post-1070859
Post in thread 'New 10kw NHX AIO From Watts247' https://diysolarforum.com/threads/new-10kw-nhx-aio-from-watts247.76813/post-1070902

I'm doing it with my setup as well as many other members that have been around here much longer than me.

I'm warming up to the idea the batteries comms can be not tied to the inverter but monitoring by SOMETHING seems important. If SA can do that, then that's a win.

Agreed.

Building your own battery bank from individual cells seems foolish these days. Even with free labor, you can't really achieve a better cost than what you can buy.

I disagree, unless your after a small storage capacity; anything over 10kWh DIY should be much cheaper.

On balancing:

The battery maker says 4 in series (48V V) is okay, and if they are slowly top charged, that should keep them in balance. When the lowest capacity battery BMS trips out, the entire series string goes away, which then means every battery in the string had the same AH usage at that moment. Then the can all recharge back to full with the same AH put back in. Still, I get the point and it is better not to put these things in series if you can avoid it.

In theory it sounds great but I've seen countless threads with members having issues. What if 1 BMS failed completely in the sealed 12V pack? Can your inverter handle 36V while you try to get a replacement?
A spare BMS in a DIY pack can be swapped in minutes.

On servicing:

I don't see any difference between a rack mount and the big brick style. A bad cell and the whole thing is busted. If you put in a replacement cell (which would be a chore for either type), it is of a different age, capacity, etc, so balancing will be off. The "servicing" of the batteries is replacing a unit entirely.

A bad cell in a DIY pack or user serviceable SOK pack can be swapped fairly easily, 5 minutes to 30 minutes depending on the build and skill level.
Age and capacity don't really matter (unless you're talking decades) , the pack will be limited to the weakest cell. Balancing should not be affected if they were at the same soc when swapped.

The rack mounts at 48V are better in this regard since they are full voltage and thus you don't break up a string.

For both of the above concerns, there are 48V 100 AH versions:

Amazon.com

View attachment 210469

$978, so similar in price. Now each one can balance all the cells in series internally. Another advantage is that you can size your system in 5 KWH chunks, not in 20 KWH chunks.

On monitoring:

Yes, they have no SA or other logging style interface, so you lose that. They do have BT with an app, and you can use that to check for faults and other issues, but it isn't an appropriate logging style interface like one that would work well with SA.


That's what matters.

I'm very excited about what one can do with solar these days. A prime factor in that is how you can drive the cost down which is key to wider adoption, which also means lower costs for everybody.

Mike C.

It really is a gratifying addiction.

 

[G00SE]

Building your own battery bank from individual cells seems foolish these days. Even with free labor, you can't really achieve a better cost than what you can buy.

until one cell arbitrarily fails, is weaker than the rest and it’s only 15 months in to the battery being in service. (Flukes happen) 350lb boxes suck to ship back and forth and laser welds are a challenge
With my hand build packs I can replace a single cell if needed and get many more years.
I’m all for the prebuilt packs, I still think there is value in building them as well. Especially in gaining the know how should one need to tinker later on

 

[Quattrohead]

The battery maker says 4 in series (48V V) is okay

Of course A salesperson is going to tell you that, take my advice and just do not do it.
And anyway why bother with this type of battery when you can now get rack units for about a grand each.

 

[Kornbread]

For the same coin it's a no-brainer, get a known quality server rack battery. Many already speak pylontech.

 

[Kornbread]

Point me to a thread on how to have the SA box interface to both the inverter and the battery bank. That sounds like a great setup.

I'm warming up to the idea the batteries comms can be not tied to the inverter but monitoring by SOMETHING seems important. If SA can do that, then that's a win.


Building your own battery bank from individual cells seems foolish these days. Even with free labor, you can't really achieve a better cost than what you can buy.


On servicing:

I don't see any difference between a rack mount and the big brick style. A bad cell and the whole thing is busted. If you put in a replacement cell (which would be a chore for either type), it is of a different age, capacity, etc, so balancing will be off. The "servicing" of the batteries is replacing a unit entirely.

The rack mounts at 48V are better in this regard since they are full voltage and thus you don't break up a string.

For both of the above concerns, there are 48V 100 AH versions:

Amazon.com

View attachment 210469

$978, so similar in price. Now each one can balance all the cells in series internally. Another advantage is that you can size your system in 5 KWH chunks, not in 20 KWH chunks.

On monitoring:

Yes, they have no SA or other logging style interface, so you lose that. They do have BT with an app, and you can use that to check for faults and other issues, but it isn't an appropriate logging style interface like one that would work well with SA.


That's what matters.

I'm very excited about what one can do with solar these days. A prime factor in that is how you can drive the cost down which is key to wider adoption, which also means lower costs for everybody.

Mike C.

For how to connect independent bms's to SolarAssistant, visit their website linked earlier.

Then it looks I am a fool since I have over 120kwh of diy battery bank that, at the time, cost about <1/3 than the price of prebuilt. Other than the time it took to charge before install, it took 5 minutes to swap out an outlying cell. SA displays the low/high cells and the jk bt app shows every cell and much more.

We're feeling a bit of attitude when we're just trying to help, or offer viable options.

 

[Kornbread]

Never tried this before. 150amp 2pole breaker. Instructions say " ... use both poles for 300amp. ... ". The previous diagram was no how to wire the breaker in parallel. Watts says simply wire them in parallel.

How do you determine when a breaker is polarized?

 

[Brucey]

Yes, the mppt limits production and the reason you can safely overpanel most mppts, to an extent. Many people overpanel so they can harvest more on cloudy days/winter knowing they will loose some production on sunny days as the mppt clips.

Battery comm is not all golden. Look at the eg4 LiFePower4, when communicating with my Growatt, the battery's baked in settings commanded the inverter to charge to ~58v, roughly 3.645v per cell. Look at the charge/discharge profile of a LiFePo4 cell and you will see maybe ~10% of its available power comes from the knees. Other than giving a passive balancer something to do, there really is no reason to take LiFePo4 cells that high. SolarAssistant shows all I need to know about my battery bank with jk bms that do not communicate with the inverter.
View attachment 210438

I think eg4 released "new" firmware to drop that charge level down from 58. Fiddling to get passive balancing to work I guess.

 

[Kornbread]

Want to be sure on this. The nhx does not, ever, switch neutral in and out, it always passes neutral from grid to the load panels?

 

[Art's Solar]

Hi, Anybody out there Know the magic trick to hooking up Solar assistant. Ian said somthing about a 4 pin connector.
Is that the plug for the solar man device?
Please help. Thanks.

 

[Kornbread]

It's a different animal that connects to one of the boards inside the inverter. small 4 pin to cat5 adapter.

 

[Kornbread]

Look correct? Ground always gets me.

The ground rod is a short 3 feet from the combiner box. Is it simpler to combine all the grounds at the ground bar inside the combiner box then take that to the ground rod, or since the main panel is the only panel bonded, do all the grounds have to terminate there and then a main ground run to the ground rod? It's ~26' from the main panel to the ground rod bussbar.
x

 

[Hedges]

Not good enough to just do a short run directly to round rod.

Ground wires must run together with L1/N/L2 from Inverter1(Load1) to sub-panel, also together with L1/N/L2 from inverter2(load1) to sub panel. Ground is always routed together with current-carrying wires (except in PV array where all are loose exposed wires.)

The ground wire from main panel directly to sub-panel isn't required, but I think it is OK.
Same goes for sub-panel to the bonding wire for ground rod, and combiner box, inverter1, inverter2 to bonding wire for ground rod.

(I could be mistaken there, maybe code requires separate connection from inverters to some ground rod, but I think back through AC wiring to main panel and on to ground rod is OK, at least if all on same structure.)

Also run ground wire from each inverter to PV panel frames.

 

[Scat]

What brand of batteries work with the 10kw NHX AIO From Watts247?
I sent a email to Watts247 on 04-22-2024 and haven't hear back.
Battery Brands:
EG4
SOK
Ruixu
BigBattery Ethos

Has anyone connected any of the above and have working coms with the battery?

Thanks
SCat

​

 

[Kornbread]

@Hedges This better?

Third paragraph, second sentence confuses me.

 

[Kornbread]

What brand of batteries work with the 10kw NHX AIO From Watts247?
I sent a email to Watts247 on 04-22-2024 and haven't hear back.
Battery Brands:
EG4
SOK
Ruixu
BigBattery Ethos

Has anyone connected any of the above and have working coms with the battery?

Thanks
SCat

​

The nhx is supposed to speak with bms's using pylontech. I 'think' eg4 uses pylontech protocol, not sure which others.

 

[Hedges]

@Hedges This better?

Third paragraph, second sentence confuses me.
View attachment 212020

Yes, that looks good.
The ground wires to sub-panel presumably enter it through same knock-outs as the power carrying wires.

"Same goes for sub-panel to the bonding wire for ground rod, and combiner box, inverter1, inverter2 to bonding wire for ground rod."
You've disconnected wires that go directly from sub-panel to ground rod, and you didn't put in a wire from combiner box to ground rod, which is fine.
But if you want to run wires from sub-panel to ground rod, combiner box to ground rod, inverter1 to ground rod, inverter2 to ground rod, that is OK too.

Often, conduit makes loops in ground. Two sources of power, both grounded, both feeding a box, also makes loops. Not a problem.

 

[Kornbread]

Sounds like this is also ok. Removed the ground wire from main panel directly to ground rod. That ground wire now runs from the main panel to a ground buss bar in the combiner box, then on to the ground rod.

One wire short of running ground in the way described in post #275. If below is fine, it saves the headache of trying to push another conductor through 26' of crowded conduit.

If it's not ok, I'll find a way to get another wire in there.

 

[Hedges]

You physically removed a ground wire that was already on your property? Or erased a green line in a CAD file?

Is utility grid involved?

With utility grid, generator, etc. as primary source, we bond Neutral to Ground at the first disconnect (main breaker service disconnect) and run a wire to ground rod. For my 200A service, that is 6 AWG minimum. We generally use 2x ground rods 6' apart (more recent code), but for some silly reason have to use minimum 4 AWG to water pipe. I have no splices, one continuous wire. Under some circumstances we're supposed to irrevocably bond if joining ground wires.

You say "Bonded" at main panel. Neutral-ground bond?
Keep the wire to ground rod there. Add more wires to ground rod if you like, but have ground wires running with current carrying wires.

 

[Kornbread]

Erased a green line in paint.

Grid is involved. Forgot to add grid feeding the main panel in the drawing.

Main (service) panel is bonded as in neutral-ground bond, and ground wire runs directly to ground rod. Only required one ground rod here, 6awg min. Sub panel not neutral-ground bonded. Apparently, our state doesn't appear to follow nec code.

Was afraid the main panel ground wire to ground rod had to be one continuous run straight to the ground rod as any splice could create resistance.