Have I F'd up?

[Mrjmegson]

Hey guys, I'm not a sparky and am intending to install my own Solar PV system.

I so far bought the panels and inverters, and am trying to get batteries. I want 8 X Pylontech US5000 batteries ideally (4 on each inverter).

However, I think I've F'd up. The inverters I've bought are FOX H1 6kw Hybrids. Everything about them seems perfect except for the battery connection.

I looked in the box yesterday and noticed the battery connections are via MC4 6mm connectors, rated at 50A max.

Now to me this doesn't sound sufficient at all, I think I need way thicker cable and a much higher Amp rating.

The inverter has the following specs:
Bat volt range 85-450v
Recommended voltage 300vdc
Max charge / discharge 6000w
Max charge/discharge Amps 35A

Battery spec: 48v nominal, charge/discharge 43-53v, recommended charge/discharge 80A, Max continuous 100A, peak 15min - 120A, 15sec - 200A.

Are these totally incompatible? The stats on my inverter seem to suggest to me that it can't handle any large batteries.

I hope you guys can explain this to me.

Thanks,

Jason

 

[up_north]

I’m fairly sure Fox inverters are designed to work with high voltage batteries like their own HV range.

 

[johnb2713]

Looking at the voltage range 85 to 450v and the rating of 6kw, to be withing 50A you would need 120v on the input, so it should be possible with the rigt choice of battery, can you run your proposed ones in series? assuming theyre 48v, 4 of them would give you 192v and for 6000w that would be well under the 50 amp rating at 31.25 amps

 

[binky]

I've never quite understood the MC4 connectors for the batteries, when all the other battery cabling is as thick as your finger, it seems undersized to use solar cable. However, soalr cable is very different in construction to other cabling and can take a much higher ampage rating, and work at higher temperatures than most cabling you can buy, so 6mm is probably perfectly adequate. Most of the batteries I've installed use 4mm solar cable om something like 3.6 inverters. 6mm is good for 70Amps according to this..

https://www.sy-solar.com/product/6mm-solar-cable/

 

[binky]

I’m fairly sure Fox inverters are designed to work with high voltage batteries like their own HV range.

fox always used to supply Pylontech batteries, so should be compatible. In fact I'm fairly sure their own batteries are Pylontech with a different badge on them.

 

[binky]

quick look on my fave wholesaler and the battery recommended with those inverters has this spec. So you would appear to be 4v out, which I'm not sure is an issue. I would phone the technical helpline for Fox.

H2600 (HV 2.6kWh)
BatteryWeight:30 kg
Battery Type:Lithium Ion
Nominal Energy:2560 Wh
Depth of discharge:90.00 %
Voltage:52 V
Continuous Discharge Rate (Normal Use):2560 W
Maximum Discharge Rate (5 Minutes):3000 W
Surge Discharge Rate (15 Seconds):3600 W
Maximum Charge Rate (5 Minutes):2560 W

 

[Mrjmegson]

Hi Johnb2713
Thanks for the comprehensive reply, I sort of understood it. The issue you raised is the battery connectivity, which when ever I look at anything to do with Pylontech batteries, they are always linked in parallel, which would increase the AMPS and not the Volts, which would put the amps over what the inverter can handle. I don't know if they HAVE to be linked in parallel, or if they can be series linked, which would solve all my problems.

Binky
(love the name by the way), thanks for your multiple replies. It's really interesting what you said about solar cable capacity, and you've made me decide to use that to link my batteries to the inverter.

I too think the Fox batteries are Pylontech, as it seems are a huge amount of brands, but the fox ones have an actual MC4 output on them, whereas the Pylontech use the huge thick cables, so I'd have to find a way to reduce this cable down some how.

I don't want to buy the fox batteries as they work out considerably more expensive.

Up-north
Are the range of fox batteries you referred to the fancy well packaged ones they do? If so, I have an email from Fox actually saying that those batteries are not compatible with their own inverters, and have been made to run with Solis. Crazy.

Thanks again, guys, I really hope I can sort this, or I've wasted a lot of money.

Slightly edited to make it easier to read

 

[Mrjmegson]

No, ignore me, I'm being a cretin, Pylontech are parallel connected, pos to pos, neg to neg, so the amperage will stay the same.

Amazing, you legends, thanks for going through this and making me realise Im being stupid.

 

[Mrjmegson]

Sorry guys, something I can't get my head round is the output of the battery, this has a continuous peak of 100A, which is double what my inverter says it will accept.

So does this mean they aren't compatible?

 

[johnb2713]

No, ignore me, I'm being a cretin, Pylontech are parallel connected, pos to pos, neg to neg, so the amperage will stay the same.

Amazing, you legends, thanks for going through this and making me realise Im being stupid.

Wrong, if theyre parallel connected the current rating is double, the voltage stays the same.

 

[johnb2713]

Hi Johnb2713
Thanks for the comprehensive reply, I sort of understood it. The issue you raised is the battery connectivity, which when ever I look at anything to do with Pylontech batteries, they are always linked in parallel, which would increase the AMPS and not the Volts, which would put the amps over what the inverter can handle. I don't know if they HAVE to be linked in parallel, or if they can be series linked, which would solve all my problems.

Slightly edited to make it easier to read

A short search revealed:-


So there you, all of your problems solved LOL

 

[binky]

Sorry guys, something I can't get my head round is the output of the battery, this has a continuous peak of 100A, which is double what my inverter says it will accept.

So does this mean they aren't compatible?

The inverter will control the output.

 

[binky]

One of mine

 

[up_north]

Hi Johnb2713
Thanks for the comprehensive reply, I sort of understood it. The issue you raised is the battery connectivity, which when ever I look at anything to do with Pylontech batteries, they are always linked in parallel, which would increase the AMPS and not the Volts, which would put the amps over what the inverter can handle. I don't know if they HAVE to be linked in parallel, or if they can be series linked, which would solve all my problems.

Binky
(love the name by the way), thanks for your multiple replies. It's really interesting what you said about solar cable capacity, and you've made me decide to use that to link my batteries to the inverter.

I too think the Fox batteries are Pylontech, as it seems are a huge amount of brands, but the fox ones have an actual MC4 output on them, whereas the Pylontech use the huge thick cables, so I'd have to find a way to reduce this cable down some how.

I don't want to buy the fox batteries as they work out considerably more expensive.

Up-north
Are the range of fox batteries you referred to the fancy well packaged ones they do? If so, I have an email from Fox actually saying that those batteries are not compatible with their own inverters, and have been made to run with Solis. Crazy.

Thanks again, guys, I really hope I can sort this, or I've wasted a lot of money.

Slightly edited to make it easier to read

No - I’m talking about their basic HV range - the ones that look like Pylontech.

 

[binky]

Thick cables go off to fused isolator, then solar cable into the inverter, Solax in this case, I'll see if I can find a photo

 

[binky]

Not a great image

 

[Mrjmegson]

Wrong, if theyre parallel connected the current rating is double, the voltage stays the same.

So I need them to be series connected?

 

[Mrjmegson]

No - I’m talking about their basic HV range - the ones that look like Pylontech.

Yeh sorry, I looked after and realised the HV range are the Pylontech lookalikes.

 

[Mrjmegson]

One of mine

Amazing, so you wire yours in series then. I've only ever seen them in parallel.

 

[Mrjmegson]

Thick cables go off to fused isolator, then solar cable into the inverter, Solax in this case, I'll see if I can find a photo

Ah that's genius, thank you.