Hello All

I have spent some time reading up on the various opinions on settings for the pylontech batteries and have changed my setting so many times according to the latest pinion or view.

I have a pair of us5000 on a conversol VM7 which I believe is also made as an axpert max. I have recently started to use the off peak overnight cheap (cheapish) power to recharge the batteries and I am trying to get a set of voltage values that will both enable long term stability of the batteries as well as ensure I am not loosing out on the capacity of the pair.

At present I have my battery cut off set to 43v. the float set to 52.0v the bulk charge voltage at 53.4v and back to battery at 53.0 v.

Now I have read that even pylontech recommend the float voltage to be 51.75 so as to keep each cell at 3.45 v as this stops the cells becoming overcharged but I believe in their own documentation they also recommend 52.5v- 53.5v as a range for charging them.

Does anyone have experience of these batteries and can you give me a bit of guidance as to the best and worst ways of charging them please?

At present I am able to get the batteries charged on utility power but they only seem to charge up to 5 of the 6 leds on the front. It may be to do with my charging regime or something else but it would help if someone has had experience of the best way to charge them. Many thanks in advance

Regards

Bony999

On 2024/11/05 at 4:07 PM, bony999 said:

Hello All

I have spent some time reading up on the various opinions on settings for the pylontech batteries and have changed my setting so many times according to the latest pinion or view.

I have a pair of us5000 on a conversol VM7 which I believe is also made as an axpert max. I have recently started to use the off peak overnight cheap (cheapish) power to recharge the batteries and I am trying to get a set of voltage values that will both enable long term stability of the batteries as well as ensure I am not loosing out on the capacity of the pair.

At present I have my battery cut off set to 43v. the float set to 52.0v the bulk charge voltage at 53.4v and back to battery at 53.0 v.

Now I have read that even pylontech recommend the float voltage to be 51.75 so as to keep each cell at 3.45 v as this stops the cells becoming overcharged but I believe in their own documentation they also recommend 52.5v- 53.5v as a range for charging them.

Does anyone have experience of these batteries and can you give me a bit of guidance as to the best and worst ways of charging them please?

At present I am able to get the batteries charged on utility power but they only seem to charge up to 5 of the 6 leds on the front. It may be to do with my charging regime or something else but it would help if someone has had experience of the best way to charge them. Many thanks in advance

Regards

Bony999

53.5v is above pylontechs max recommendation and will in all probability ruin them, especially if the inverter overshoot.

Hi Tinbum

Thanks for the reply. Following on from an item I read on this forum regarding battery charging of marine batteries I decided to opt for the settings they recommended for Li-Ion batteries.

I have now set my bulk charging voltage to 52.5v which is 3.5v per cell and the float to 49.8v which is 3.32 v per cell.

I think this is recommended for a longer life of the batteries and I assume is due to not over charging/exciting the cells.

The thing I find difficult to understand is how some of the terms relate to the process of charging. For instance the back to battery voltage,  I have this currently set to 53v which is 3.53v per cell and below the figure you quoted in your reply. I set it at 53v so that it was above the bulk voltage in the expectation it would keep charging until the battery got to 53v then it would stop charging and the battery would then settle back to the float volttage. Is this how the charging works or is setting the back to battery voltage needed to be higher or lower than it is presently? I assumed if I set it to 52v then it would only charge the battery to this voltage and stop so it would not attain the bulk voltage setting of 52.5v

I am going to leave the settings for bulk and float as they are above but if you can shed more light on the methodolgy of the charging and the relevance of the voltage settings I would be very happy to hear from you.

Regards

Bony999

I have no knowledge on your inverter so can't advise on how to set it up.

I always use CAN communication and then the BMS tells the inverter what it wants and the inverter shouldn't get it wrong, though their are a lot of inverters that don't have very good control of their voltages.

Ok thanks for the original reply Tinbum

 

On 2024/11/08 at 3:05 PM, Tinbum said:

I have no knowledge on your inverter so can't advise on how to set it up.

I always use CAN communication and then the BMS tells the inverter what it wants and the inverter shouldn't get it wrong, though their are a lot of inverters that don't have very good control of their voltages.

Hi, I did the same but it seems that some battery manufacturers can also get it wrong, I have used 2x Pylontech UP5000 batteries on 2x Growatt inverters for three years using default settings (battery type "LI" for lithuim) with the CAN connection taking care of all. Today I pulled one of the batteries out because it was prematurely discharging only to find it had become quite swollen. Pylontech was feeding a value of 53.2V to the inverter and in effect destroying itself.