Hi

I have a "Mecer SOL-I-BB-M2L Mecer 2Kw 25.6V 100Ah Lithium Battery 820W MPPT" that I purchased a little over two months ago.

I've run into an issue where it is no longer charging the battery, and has run empty as a result.

It is only plugged into the main and receives power.
I've tried pressing the "battery switch" and "AC Input Protect" switch at the back while both plugged in and not, but it made no difference.
I've also tried switching it off at the front while leaving it plugged in while on setting 01 - P3, which is supposed to just charge the battery according to the manual.

It could just be because the battery has now run empty, but it appears that the Battery Switch isn't doing anything. I'm not sure what caused this, or how to fix it.

Any assistance would be greatly appreciated.

2 hours ago, platpoot said:

It could just be because the battery has now run empty,

Yes. Hopefully another owner will come through with how to recover from that, and hopefully you don't have to open it up to individually and slowly and carefully recharge each cell.

I guess that photo is from a time when it was working, not from the last charge cycle. It would be good to know if the inverter thought it was charging, or had some sort of fault code showing.

I'm not familiar with this model. What does the 01 in the middle signify?

2 hours ago, Coulomb said:

 

I'm not familiar with this model. What does the 01 in the middle signify?

Is that not the normal fault code as used by Voltronic inverters. Code 01 is normally the fan blocked which does not seem of value here. 

It might be of value to see the current screen of the inverter even when in line mode. 

To answer the questions. The green light for "Line" indicates the inverter is receiving power from the mains. The [01] indicates the charging type (in this case, priority from the mains, then battery as a failover). And the 0% under BATT indicates the charge level for the battery.

Update:

After some fiddling I was able to get the battery charging. I only know this, because it stayed on for a while after load shedding started.
My current assumption is that it is related to a known issue regarding calibration/firmware (as indicated by this post https://mybroadband.co.za/forum/threads/mecer-sol-i-bb-m2l.1232227/post-30991951). 

After Googling it seems there is only two know ways around it. To either deplete the battery and charge it back up to full (which didn't work), or to get a firmware update for the device.
I emailed both Mercer and Mustek, and surprisingly Mustek came back relatively quickly. I'm going to take the device to one of their service centers to have it fixed.

2 hours ago, platpoot said:

To answer the questions. The green light for "Line" indicates the inverter is receiving power from the mains. The [01] indicates the charging type (in this case, priority from the mains, then battery as a failover). And the 0% under BATT indicates the charge level for the battery.

Update:

After some fiddling I was able to get the battery charging. I only know this, because it stayed on for a while after load shedding started.
My current assumption is that it is related to a known issue regarding calibration/firmware (as indicated by this post https://mybroadband.co.za/forum/threads/mecer-sol-i-bb-m2l.1232227/post-30991951). 

After Googling it seems there is only two know ways around it. To either deplete the battery and charge it back up to full (which didn't work), or to get a firmware update for the device.
I emailed both Mercer and Mustek, and surprisingly Mustek came back relatively quickly. I'm going to take the device to one of their service centers to have it fixed.

Good to hear at least you making progress. We were expecting your display to match the Axpert display as your LEDs as well as 4 buttons do match the Axpert. 

In this picture of an Axpert the display does not show which priority is selected. Those Centre 2 digits are reserved for the setting number(tool) when changing settings or for the error codes. (!) 

Always a problem to know what the display implies when having a different make or family. 

17 hours ago, Scorp007 said:

We were expecting your display to match the Axpert display as your LEDs as well as 4 buttons do match the Axpert.

Yes, for a long time I thought that the above LCD pattern was designed and manufactured by Voltronic for their Axperts, and that any other inverter manufacturer that used it was illegally copying it. Whether that's true or not, it seems now to be a commonly available component, and is used by many manufacturers, not all of which are attempting to copy Axperts or to necessarily look like them.

As for the four buttons, again it looks like copying the Axperts / Infinis, but on the other hand, it's a sort of usable minimum user input system and you pretty much always need an up and a down button, etc. So it's not that surprising to see this.

You could say the same thing for the four LEDs, but taking together these three aspects (LCD, buttons,  and LEDs), it does seem a bit much of a co-incidence. Perhaps they thought that looking a bit like a well-known, fairly well respected brand is no bad thing, while taking steps to ensure that there was some differences that they could point to in court, should the need ever arise.

We will try and remember which with age becomes difficult that the multi color buttons on a Mecer does not correspond with the Mecer models that are not housed in a trolley. 

We too easily assume the same make will use a standard display unit as well as the same codes for various settings. A selection of displays without the new large display.

 

 

For a final update to this thread I have received a note from Mustek on how to reset the battery management software. I do not now if these steps work, however because I could not find how to do this online I will post it here in case anyone else wants/needs to perform a battery reset on a Mecer SOL-I-BB-M2L Mecer 2Kw 25.6V 100Ah Lithium Battery 820W MPPT:

How to reset the battery management system:
1. Ensure you unit is on and displaying 0% battery state of charge.
2. Press and hold the battery switch (silver switch at the side panel for at least 6 seconds).
    When you leave the battery switch the unit will shut down.
3. Press the battery switch again but only for 1 second similarly to switch it on.
4. Press and hold the on/off button until the unit gives you a display.
5. Use the navigation up button (blue up and down buttons at the front panel), press it once to see the state of charge.
6. The state of charge should be 100% if the unit was fully charged.

On 2024/02/26 at 6:21 PM, platpoot said:

For a final update to this thread I have received a note from Mustek on how to reset the battery management software. I do not now if these steps work, however because I could not find how to do this online I will post it here in case anyone else wants/needs to perform a battery reset on a Mecer SOL-I-BB-M2L Mecer 2Kw 25.6V 100Ah Lithium Battery 820W MPPT:

How to reset the battery management system:
1. Ensure you unit is on and displaying 0% battery state of charge.
2. Press and hold the battery switch (silver switch at the side panel for at least 6 seconds).
    When you leave the battery switch the unit will shut down.
3. Press the battery switch again but only for 1 second similarly to switch it on.
4. Press and hold the on/off button until the unit gives you a display.
5. Use the navigation up button (blue up and down buttons at the front panel), press it once to see the state of charge.
6. The state of charge should be 100% if the unit was fully charged.

This worked for me, thanks

I had a similar problem with my Mecer SOL-1-BB-M2L 2Kw inverter.The battery display showed a o present display on the front screen and wasn't taking any charge from mains or solar.I followed the advice given by Mustek and reset my inverter battery state back to 100 present.It is now working as normal.Thanks a lot for your assistance and that you posted your problem and saved me the trip to Mecer.

On 2024/02/26 at 6:21 PM, platpoot said:

For a final update to this thread I have received a note from Mustek on how to reset the battery management software. I do not now if these steps work, however because I could not find how to do this online I will post it here in case anyone else wants/needs to perform a battery reset on a Mecer SOL-I-BB-M2L Mecer 2Kw 25.6V 100Ah Lithium Battery 820W MPPT:

How to reset the battery management system:
1. Ensure you unit is on and displaying 0% battery state of charge.
2. Press and hold the battery switch (silver switch at the side panel for at least 6 seconds).
    When you leave the battery switch the unit will shut down.
3. Press the battery switch again but only for 1 second similarly to switch it on.
4. Press and hold the on/off button until the unit gives you a display.
5. Use the navigation up button (blue up and down buttons at the front panel), press it once to see the state of charge.
6. The state of charge should be 100% if the unit was fully charged.

Hi all. I am having this same issue after my battery ran flat during moving home.

I have tried these steps but when i hold the battery button down, nothing happens. The decice does not reset. Am i missing something.

At the moment the battery does not charge and the moment i remove the power cable it turns off.

Edited October 18, 2025Oct 18 by trinomic

I have also opened it up and disconnected the bettery for a few minutes to do a hard reset but the issue persists.

Edited October 18, 2025Oct 18 by trinomic

My inverter does the same thing. Once I pull the plug out I’m unable to keep it on. My battery first showed 0%, I tried the reset settings above, and now my battery shows 100% but still does not power on without being plugged in. Any advice please 😔

Doesnt look like there is a solution for this. Mine is just taking up too much space for no reason at home at the moment.

Its also such a terrible thing to load into the car and take all the way to Mustek for diagnostics. I suppose I will find motivation when LS reappears.