Timothy Whitehead Posted September 4 Share Posted September 4 I have a US5000 pylontech battery that was discharged and left in storage for some time. As far as I can tell there is no other issue with it. When I got it, the BMS comes on but in BatteryView it was showing low voltage errors. I put it on an inverter and it charges very slowly (0.2A or less) and keeps going into idle. I have been trying to do this for some days and it has at times got up to 48.4V. However it spends most of its time in idle mode. I assume this is some special protection mode of the BMS. What I want to know is if I ever get it to full will it sort itself out and then behave normally? Or is there something else that must happen? Or are the cells permanently damaged? Or should I be doing something different? Quote Link to comment Share on other sites More sharing options...
HendrikBigChief Posted September 4 Share Posted September 4 2 hours ago, Timothy Whitehead said: I have a US5000 pylontech battery that was discharged and left in storage for some time. As far as I can tell there is no other issue with it. When I got it, the BMS comes on but in BatteryView it was showing low voltage errors. I put it on an inverter and it charges very slowly (0.2A or less) and keeps going into idle. I have been trying to do this for some days and it has at times got up to 48.4V. However it spends most of its time in idle mode. I assume this is some special protection mode of the BMS. What I want to know is if I ever get it to full will it sort itself out and then behave normally? Or is there something else that must happen? Or are the cells permanently damaged? Or should I be doing something different? What inverter do you have, on a Deye/Sunsink inverter there is an "activate battery" checkbox that should help ressurrect a discharged battery. But yes, having a lithium battery at 0% in storage is not a good idea. Quote Link to comment Share on other sites More sharing options...
Tinbum Posted September 4 Share Posted September 4 3 hours ago, Timothy Whitehead said: I have a US5000 pylontech battery that was discharged and left in storage for some time. As far as I can tell there is no other issue with it. When I got it, the BMS comes on but in BatteryView it was showing low voltage errors. I put it on an inverter and it charges very slowly (0.2A or less) and keeps going into idle. I have been trying to do this for some days and it has at times got up to 48.4V. However it spends most of its time in idle mode. I assume this is some special protection mode of the BMS. What I want to know is if I ever get it to full will it sort itself out and then behave normally? Or is there something else that must happen? Or are the cells permanently damaged? Or should I be doing something different? Firstly how are you measuring the voltage? Have you actually managed to read a voltage from the battery connections with it NOT connected to the inverter? If their is no voltage then you may well have to open the battery up and attach a small power supply to the cells directly. Quote Link to comment Share on other sites More sharing options...
zivva Posted September 4 Share Posted September 4 (edited) You may be able to disable protection of the BMS or decrease the minimum voltage for a cell to not accept current but stay idle on BatteryView to be able to charge the battery. What kind of voltage displays BatteryView for the lowest cell(s) ? As long as > 2.0V, you should be fine and get full or close to full capacity after full charge. If < 2.0V ... It depends how much time the said battery has been in storage ... Anyway, you will need to initially charge the battery at a quite low C-rate (0.1 to 0.3C) and monitor individual cell voltages to see how they behave ... Edited September 4 by zivva Quote Link to comment Share on other sites More sharing options...
Steve87 Posted September 4 Share Posted September 4 From memory the pylontechs in low voltage protection needs a 2A charge current to stay on. Helps if you have a 48V adjustable power supply to do this. Otherwise it's a catch 22. BMS awakens, states low voltage alarm turns off. Then turns on then repeats. Quote Link to comment Share on other sites More sharing options...
Timothy Whitehead Posted September 4 Author Share Posted September 4 7 hours ago, Tinbum said: Firstly how are you measuring the voltage? I am using the BatteryView software from Pylontech. It tells me the voltage of the battery as a whole as well as the individual cells. The current voltages are higher than my other batteries when they are very low (which are working fine) Quote Link to comment Share on other sites More sharing options...
Timothy Whitehead Posted September 4 Author Share Posted September 4 5 hours ago, zivva said: What kind of voltage displays BatteryView for the lowest cell(s) ? 3.22 and all about the same (3.22 - 3.222) Quote Link to comment Share on other sites More sharing options...
Tinbum Posted September 4 Share Posted September 4 1 hour ago, Timothy Whitehead said: I am using the BatteryView software from Pylontech. It tells me the voltage of the battery as a whole as well as the individual cells. The current voltages are higher than my other batteries when they are very low (which are working fine) You need to measure the voltage at the terminals Steve87 1 Quote Link to comment Share on other sites More sharing options...
zivva Posted September 5 Share Posted September 5 (edited) 14 hours ago, Timothy Whitehead said: 3.22 and all about the same (3.22 - 3.222) Which is very far from being discharged but nominal voltage when no current is flowing ... Screenshot of what says BatteryView ? For both with terminals connected to load / inverter and terminals disconnected from anything. Edited September 5 by zivva Quote Link to comment Share on other sites More sharing options...
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