Hi all

I always remembered 80% usable capacity for the Pylon US3000 specs (2.8kWh) and their 6000 cycle life claim (this figure is also still listed on some online-shops).

However, just having looked at the both the Pylon website as well as the manual of my latest Pylon (I unfortunately cannot find the manuals of my older ones...), both of them state 90% usable capacity (3.2kWh).

Is my memory completely off or has the usable capacity changed at one point? 

 

As far as I am aware the BMS will shutdown at 10%SoC (state of charge) - hence 90% available for use. However the 6000 cycles is based on not going below 20%SoC.
So the Us3000 is nominally 3.5kw but useable is 3,2kw.And if you want the >6000 cycles, dont drain the batteries below 20%SoC. If you do drain it regulalrly so that the BMS shutsdown, the rated cycles drop to something like 4500

2 hours ago, starmage said:

the BMS will shutdown at 10%SoC

Not exactly. The BMS will ask the inverter to please stop discharging at 10% (if you have some sort of communication channel), but you can take it below 10%. I know, because when we test these things, we actually hack out the comms part and we take it right down to zero to see when the battery really switches off (so that it can be documented for support purposes).

On a Victron system, the battery will indeed send DCL=0 (discharge current limit) at 10%, and this will cause it to stop discharging, or switch off if there is no grid. But in an emergency... you can use that last 10%.

Thanks @starmage and @plonkster

7 hours ago, starmage said:

However the 6000 cycles is based on not going below 20%SoC.
So the Us3000 is nominally 3.5kw but useable is 3,2kw.And if you want the >6000 cycles, dont drain the batteries below 20%SoC.

This is also what I thought. But then both the Pylon website as well as the manual mention several times 'more than 6000 cycles with 90% DoD' - e.g.

and

and

This made me question my assumption of not going below 20% DOD to achieve more than 6000 cycles.

Any thoughts?

lol and then you get the following product specs on their website (http://www.pylontech.com.cn/pro_detail.aspx?id=121&cid=23) - that only speaks to >4500 cyles.

But even the worst numbers will give you more than 10years of daily cycle use.

Personally mine is set to only discharge to 40% on daily use - the rest is left for possible loadshedding (Tshwane only have 2hr load shedding slots)

 

I see a new test report is out:

https://batterytestcentre.com.au/wp-content/uploads/2020/05/Battery-Testing-Report-8-April-2020.pdf

At about 1600 cycles (4.5 years) having around 85% usable capacity left and seems to still be going strong while some of the other friends have died along the way. 

1 hour ago, starmage said:

lol and then you get the following product specs on their website (http://www.pylontech.com.cn/pro_detail.aspx?id=121&cid=23) - that only speaks to >4500 cyles.

Yeah - I also saw that. But that might be an older version of the same doc - which made me think whether the usable capacity figure might have also changed in the meantime

1 hour ago, starmage said:

Personally mine is set to only discharge to 40% on daily use - the rest is left for possible loadshedding (Tshwane only have 2hr load shedding slots)

I play around with my settings if we get into loadshedding times. Fortunately I am supplied by COCT and they are very reliable with their loadshedding forecasts. So if I am only scheduled for day-time loadshedding, I run my batteries down close to 20% - but if we have night-time ahead of us, I'll adjust that number to make sure that I still have sufficient reserves for that 'special' time of the day

1 hour ago, PaBz0r said:

I see a new test report is out:

Thanks 👍 I had read a previous report but not the latest update.

They also seem to be using 20% DOD for their test 

Edited July 15, 20205 yr by wolfandy
Forgot something

We currently have a  power failure since around 20:00 last night, the batteries went sub 30% this morning for the first time ever. Nothing popped up yet.. sun came out at the perfect time and they are over 40% again

2 hours ago, PaBz0r said:

We currently have a  power failure since around 20:00 last night, the batteries went sub 30% this morning for the first time ever. Nothing popped up yet.. sun came out at the perfect time and they are over 40% again

Noice!!! 

I've got a kodak king 5.48 inverter paired with 4x 3.5kw pylontech batteries. I've been struggling to get them to connect back to grid at the 80% use, but due to the inverter working on voltage increments of 1. Mine is set to 47 volts and only charges from grid when it's on 91%. I've tried 48 volts, but then I see the battery charging from grid anywhere between 40% - 80%.

Was hoping as soon as the alarm triggered for 80% usage the batteries would start to charge from the grid. 

Any ideas how to get around this without additional software add-ons? 

Much appreciated. 

7 hours ago, WezHo said:

......... but due to the inverter working on voltage increments of 1.

Mine is set to 47 volts and only charges from grid when it's on 91%.

I've tried 48 volts, but then I see the battery charging from grid anywhere between 40% - 80%.

I have the same(ish) problem with my setup 🤓

I agree if there was increments of 0.1V we could obtain satisfactory results 👍

Best is to get Solar assistant or something of the sort.

You connect the batteries directly to the Pi and it reads the State of charge.

You can then use the following to change inverter settings.

 

26 minutes ago, Jacques Ester said:

Best is to get Solar assistant or something of the sort.

You connect the batteries directly to the Pi and it reads the State of charge.

You can then use the following to change inverter settings.

My system is to be used in a Broadcast Radio transmitter room directly below the antenna system 😎

The area is flooded with a blanket of RF which will surely cause problems with a Raspberry Pi.