Skip to content
View in the app

A better way to browse. Learn more.

Power Forum - Renewable Energy Discussion

A full-screen app on your home screen with push notifications, badges and more.

To install this app on iOS and iPadOS
  1. Tap the Share icon in Safari
  2. Scroll the menu and tap Add to Home Screen.
  3. Tap Add in the top-right corner.
To install this app on Android
  1. Tap the 3-dot menu (⋮) in the top-right corner of the browser.
  2. Tap Add to Home screen or Install app.
  3. Confirm by tapping Install.

Axpert MKSII 5kW Not Charging Lithium Battery Fully

Featured Replies

Hi guys.

I'm new to the forum but have been reading a lot of posts from here to try figure out whats happening with my inverter and really hoping someone can help me out.

I have the Axpert MKSII 5kW inverter that i purchased from Full Circle Solar in Jhb.It says the main CPU version is 71.50 and it was manufactured in April 2019.

I set it up this weekend but not running any panels at the moment as i am waiting for them to arrive. So the battery is charging off utility when we get it and just running the Tv , lights, Decoder, Wifi and a few small other items, max load i use is 500W for now.

The problem i have is it is only charging the battery to 70% SOC according to the BMS on the battery pack. (I have a Leoch 48100CB LFeLi, I didn't purchase this battery. It was given to me by someone who left the country as i live in Zim)

The screen on the battery was showing the pack Voltage at 49.77V , the SOC at 68.89% and cell voltages at 3318mV (it has 15 cells) and 3 SOC lights where on.

The inverter was saying it was 49.6V and was showing two bars on the battery.

 

I have tried different voltages for bulk and float (settings 26 & 27) but when it gets to 70% it stops charging the battery, The charging light stays solid and the battery says its discharging.

These are the settings i have at the moment

01 - SBU

02 - 50A

03-UPS

04 - SDS

05 - USE

06 - LRE

07 - TRE

09 - 50Hz

11 - 50A

12 - 48V (dont think this matters without having panels)

13 - 51V (same as 12)

16 - CUT

18 - BON

19 - ESP

20 - LON

22 - AON

23 - BYD

25 - FEN

26 - 53.5V

27 - 52.7V

29 - 47V

31 - SBD

32 - AUT

33 - EDS

When it is charging the battery it says it is charging it at 21A but i have it set to 50A, is it suppose to charge at that. Any info on what i need to change or do to get it to charge the battery fully would be much appreciated.

 

20190909_102048.jpg

20190909_102122.jpg

1 hour ago, George17 said:

The problem i have is it is only charging the battery to 70% SOC according to the BMS on the battery pack.

The screen on the battery was showing the pack Voltage at 49.77V , the SOC at 68.89% and cell voltages at 3318mV (it has 15 cells) and 3 SOC lights where on.

Interesting. The web site says they have 16 cells.

Quote

The inverter was saying it was 49.6V and was showing two bars on the battery.

Pay no attention to the SOC reading (percentage or bar graph) on the inverter. It's estimating the SOC assuming a lead acid battery.

Quote

I have tried different voltages for bulk and float (settings 26 & 27) but when it gets to 70% it stops charging the battery, The charging light stays solid and the battery says its discharging.

Is this the charging LED (middle of the 3) or something on the battery itself? 

Quote

These are the settings i have at the moment

26 - 53.5V

27 - 52.7V

Those seem high for a 15S battery, but low for a 16S. But 49.77 V seems way too low for 16S. I wonder if it's actually 16S with one cell collapsed to zero volts. That could partly explain why it was given away. Is it possible to get inside to check, and perhaps read cell voltages? Though as I type this, I realise that 49.77 / 15 = 3318 mV, so that really seems to nail it as 15S.

53.5 / 15 = 3.57 V, which with a bit of overshoot might be causing the BMS to prevent charging somehow. Pesumably the only way it can do that is to disconnect the battery. Your inverter with the 450V max Solar Charge Controller can operate without the battery, though I thought it would show this on the LC Display. Does the battery icon disappear or flash or similar when the charging stops? Actually, it might only be able to operate without a battery if there is PV power available. 

Quote

When it is charging the battery it says it is charging it at 21A but i have it set to 50A, is it suppose to charge at that.

Certainly [ edit: at least early in the charge ]. I wonder if you might have high resistance in the battery cable perhaps, or in the fuse or isolator.

Edited by Coulomb

  • Author

Hi Coulomb.

Is this the charging LED (middle of the 3) or something on the battery itself?  -YES,  The charging light on the inverter stays solid saying the battery is fully charged but the SOC lights on the battery itself only has 3 of the 4 lights on and if i go into the menu on the battery it says its at 70% charge.

I can try change the battery cable and see if that helps. I'll also have a look this evening to see what happens with the battery icon when it stops charging. I can also open it up and see if there is actually 15 or 16 cells.

Should i change settings 26, 27 and 29 to something else and if so any ideas ?

What voltage should each cell be if the battery is fully charged? 

I'm really stuck on this and not too sure what else i can do.

 

http://www.leoch.com/pdf/reserve-power/Lithium/LFeLi-48100C.pdf

I have the one with the screen on it (48100CB)

  • Author

I changed the Battery cables last night, but still only charged to 70%.

I know someone else who has the same batteries (x2) running on his MKS 5kW and asked him to check the cells on his and both of his have 15. His do charge to full though !!

Decided to go through the manual again last night and i saw it says the Min battery bank size should be 170AH, I've got 100Ah. Could this be a causing a problem at all.

I did read a post about making the Bulk and the Float the same values - Is it worth trying this ? If none of the above are the problem would connecting a separate smart charger to the battery help get it up to 100% as it seems the inverter is stopping the charge when its getting to 70%SOC or do i just have the wrong settings on 26, 27 and 29.

Do you have the user manual for the battery?  I have a very old manual, so I'm not even sure if it is for the same generation of Leoch, but the float values I have are 53.5 - 54.4. 

  • Author
49 minutes ago, Tacet said:

Do you have the user manual for the battery?  I have a very old manual, so I'm not even sure if it is for the same generation of Leoch, but the float values I have are 53.5 - 54.4. 

I don't have the user manual for it and can't find anything for it online. May i ask what the Bulk value is in your manual.

Found the following BMS software for Leoch. Would i be able to get any certain values of it that could help me out.

https://drive.google.com/file/d/1BBnAYRHpGbXI9p2eVA3JUldGf4QvfL9X/view

BMS1.PNG

BMS2.PNG

Edited by George17
Left out something

They give an equalization charge voltage of 56.0 V-57.6 V, but not a bulk charge value.

Have you asked your supplier for the manual?  They should be able to provide it.  Otherwise, I think Averge is bringing Leoch in; they might be willing to assist if your supplier can't.

10 minutes ago, Tacet said:

They give an equalization charge voltage of 56.0 V-57.6 V, but not a bulk charge value.

Um, that and the 53.5-54.4 V for float sound like lead acid values. Most Leoch batteries are lead acid; only a few of the recent models (as far as I know) are Lithium Ferrous Phosphate (LFP). 56.0 V is over 3.73 VPC; this is not a safe value for a 15S LFP battery. Besides, LFP batteries don't need equalisation; that's a lead-acid thing.

So I think we're talking about very different models of Leoch battery here.

  • Author
11 minutes ago, Coulomb said:

56.0 V is over 3.73 VPC; this is not a safe value for a 15S LFP battery

How many VPC would give you a 100% SOC on a 15S or does it not work like that.

BMS1.PNG

BMS2.PNG

28 minutes ago, George17 said:

How many VPC would give you a 100% SOC on a 15S or does it not work like that.

Unfortunately, it doesn't work like that for LFP cells. You need to hold about 3.45-3.55 VPC until the current decreases to about C/20. So for a 100 Ah battery (C=100), that's around 5 A.

  • 5 months later...

Hi George17

Picked up on this string, I am based in Zim as well, also with leoch batteries, same as what you have, I see you have dived pretty deep into these. 

 

Was wondering if you have managed to pick up the settings for these batteries as what I have been able to find on the net has been limited. Ideally looking for Float and Absorbtion settings, as my multi plus 2 is disconnecting  at full charge, which I am led to believe is the battery themselves disconnecting from the inverter so as to not over charge. This essentially shuts the inverter down.

 

So looking to fine tune the settings on the victron. In the absence of BMS connection as these batteries are not supported by victron again as I am led to believe. So any help or insight from your side would be appreciated

 

 

I am based in Zim too and have been looking through this thread. My Leoch/Averge lithium ion phosphate batteries are all new and have their original manufacturer stickers on them. They too are 15s and are the 48v 100ah variety. I currently have 4 of them hooked up to my 5kw inverter and 12 x 330 watt panels feeding this all. 

The stickers on the battery have the following information. If you would like, I will upload a picture of the actual sticker and I can upload the manual that came with them too. 

Charging voltage 52.5 - 54v

Float charge voltage 51 - 51.75v

Maximum discharge current 100amps

Maximum charge current (stand alone) 100amps

Maximun charge current (parallel) 50amps

Recommended charge current 20amps

 

Edited by zimcommando
Addition of info

  • 1 month later...
On 2020/02/14 at 11:41 AM, zimcommando said:

I am based in Zim too and have been looking through this thread. My Leoch/Averge lithium ion phosphate batteries are all new and have their original manufacturer stickers on them. They too are 15s and are the 48v 100ah variety. I currently have 4 of them hooked up to my 5kw inverter and 12 x 330 watt panels feeding this all. 

The stickers on the battery have the following information. If you would like, I will upload a picture of the actual sticker and I can upload the manual that came with them too. 

Charging voltage 52.5 - 54v

Float charge voltage 51 - 51.75v

Maximum discharge current 100amps

Maximum charge current (stand alone) 100amps

Maximun charge current (parallel) 50amps

Recommended charge current 20amps

 

Please could you upload the manual

  • 3 months later...

hi guys, please could you upload de manual

i can´t get the battery to start, just an alarm after moved it to my home 

it seems it has an anti shock proteccion

 

cheers

  • 6 months later...
On 2019/09/10 at 8:58 PM, George17 said:

How many VPC would give you a 100% SOC on a 15S or does it not work like that.

BMS1.PNG

BMS2.PNG

are you installed this software?why the software always disable the USB connection after started and can't find serial com

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

Account

Navigation

Search

Search

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.