PylonTech Batteries and Hybrid inverters

[Stan]

Will Prowse on youtube often buys LiFePOs but warns about the danger of receiving grade b batteries which have had some use and which are literally swollen from their previous life. Getting an answer from the supplier then becomes an issue.

[Stinsy]

Will Prowse on youtube often buys LiFePOs but warns about the danger of receiving grade b batteries which have had some use and which are literally swollen from their previous life. Getting an answer from the supplier then becomes an issue.

I watch that guy’s videos. It’d be great if you could build your own pack for half the price of a Pylontech. But the reality is the cost of building your own pack is very, very, close to the price of Pylontech. We’re working with commodity products at commodity prices…

[Tinkering]

No problem mentioning brands. I have a cheap/cheerful LuxPower inverter/charger linked to my stack of Pylontech batteries. It works well, the web based user interface is a little clunky, but it does its job and I haven't heard any stories of unreliability. Solax, SoFar, and Solis are also well regarded at the cheap end of the market.

Pylontech batteries are not just cheap per kWh they perform very well compared with other batteries. Here is a great long term study: https://batterytestcentre.com.au/wp-con ... 021-V3.pdf.

The question of how much storage you need won't have a definitive answer. If you're all out in the daytime, you don't have a DHW tank, and you don't want to "spill" a drop of precious electric to the grid would require 4x your kWp on kWh. So that'd be 6x 2.4kWh batteries. However if you're home in the daytime and can time your usage to coincide with the sun shining (eg wash your bedding, run the dishwasher, etc.) then you don't need as many batteries, also if you have a "diverter" on your immersion heater and can therefore make use of excess power when the batteries are full you don't need as many batteries. Conversely, if you have a ToU tariff (eg Octopus Go) you can make good use of batteries even when there is little-to-no sunshine.

Many people find it useful to install the inverter/charger with 2-3 batteries, then add more as funds allow and once you've seen the benefits in action.

What kind of tumble drier do you have? I bought a cheap Beko heat-pump drier a few years back and it uses very little electricity. Before we had kids we didn't need a drier, and I'm sure some families do without one, but the volume of washing a family creates really does require one.

I have a question regarding the Lux Hybrid unit you have please,

i am about to install nearly 5kw of panels on my sons house and considering using one of these with the Pylontech Batteries.
However i am a little concerned looking at the specs that it is limited to a max of 3.6 kw output from the panels even thought the maximum input appears to be 5kw, is this correct and i guess if it is and you are generating more then the excess will just be clipped ?
If this is the case would we be better off getting the 5kw version.

As you can see from my signature i have the Lux Ac units which im very happy with but as this is a complete new system i thought it would be better
with a Hybrid unit rather than them ..

we are not too worried about the max 3.4kw output from the batteries but it would be nice when on a nice sunny day we get the maximum use of the available solar.

any help would be gratefully received.

[Stinsy]

No problem mentioning brands. I have a cheap/cheerful LuxPower inverter/charger linked to my stack of Pylontech batteries. It works well, the web based user interface is a little clunky, but it does its job and I haven't heard any stories of unreliability. Solax, SoFar, and Solis are also well regarded at the cheap end of the market.

Pylontech batteries are not just cheap per kWh they perform very well compared with other batteries. Here is a great long term study: https://batterytestcentre.com.au/wp-con ... 021-V3.pdf.

The question of how much storage you need won't have a definitive answer. If you're all out in the daytime, you don't have a DHW tank, and you don't want to "spill" a drop of precious electric to the grid would require 4x your kWp on kWh. So that'd be 6x 2.4kWh batteries. However if you're home in the daytime and can time your usage to coincide with the sun shining (eg wash your bedding, run the dishwasher, etc.) then you don't need as many batteries, also if you have a "diverter" on your immersion heater and can therefore make use of excess power when the batteries are full you don't need as many batteries. Conversely, if you have a ToU tariff (eg Octopus Go) you can make good use of batteries even when there is little-to-no sunshine.

Many people find it useful to install the inverter/charger with 2-3 batteries, then add more as funds allow and once you've seen the benefits in action.

What kind of tumble drier do you have? I bought a cheap Beko heat-pump drier a few years back and it uses very little electricity. Before we had kids we didn't need a drier, and I'm sure some families do without one, but the volume of washing a family creates really does require one.

I have a question regarding the Lux Hybrid unit you have please,

i am about to install nearly 5kw of panels on my sons house and considering using one of these with the Pylontech Batteries.
However i am a little concerned looking at the specs that it is limited to a max of 3.6 kw output from the panels even thought the maximum input appears to be 5kw, is this correct and i guess if it is and you are generating more then the excess will just be clipped ?
If this is the case would we be better off getting the 5kw version.

As you can see from my signature i have the Lux Ac units which im very happy with but as this is a complete new system i thought it would be better
with a Hybrid unit rather than them ..

we are not too worried about the max 3.4kw output from the batteries but it would be nice when on a nice sunny day we get the maximum use of the available solar.

any help would be gratefully received.

The most that can be output to the grid or to power domestic loads is 3.6kW the most that can be put into the batteries is 3.4kW.

The VAST majority of the time these limits are irrelevant. However if your solar is producing 4kW while your house is using 4kW then 400W will go into the batteries and 400W will be imported from the grid. Only if the batteries are full will power be "clipped" in this situation.

IIRC you can officially connect 8kWp of solar to the inverter, unofficially you can connect more so long as you keep the string-Voltage below 550V (IIRC).

The reality is that most of the time your array produces less than it's rated power due to temperature on the sunniest mid-summer days, or cloud, or sun angle in winter.

The downside of the 5kW version is that you need permission form the DNO.

[sharpener]

My DNO (WPD) insisted that I downrate my 5kVA Victron inverter/charger to 3.7kW to prevent any possibility of it putting more than 3.68kW back into the grid. Also they will not allow more than 3.68kW solar PV to be connected to the inverter's AC Out terminals - even though this is subject to the inverter's overall limit so it shouldn't matter (and they can't detect it anyway).

Their main concern appears to be avoiding voltages greater than 253V appearing anywhere on their distribuition network.

I plan to add a further 3kW+ of solar panels but these will be connected via a DC MPPT directly to the battery to get around the issue. Victron appears to do a good job in prioritising consumption, then charging, lastly export (though there are still a few wrinkles), so conceptually I will be capable of meeting >7kW of local loads from all the PV.

[billi]

haven't mentioned the hybrid inverter as I am not sure of forum rules and still under the old place habit of not mentioning brand names.

Moxi

well , who cares ? you mentioned the battery brand anyway , so get a Victron

And make sure the Battery capacity is big enough , cause only that - or/and a supersized PV , provides a higher level of independence

[Tinkering]

ok thanks for the information .. i think we will go with a 5kw standard inverter with a ct clamp to limit export
and the Lux Ac unit.

The cost works out about the same for the 2 units or the 5kw hybrid unit.