Hello

My inverters won't charge the batteries at more than 100a each 200a combined even with the max charge rate set to 150a.

There seems to be some sort of hard limit they won't go past no matter what.

Solar panels will produce more power if building demand goes higher so I know there's more capacity to charge but it just won't draw over 100a from the panels 

What batteries are you using and how many per inverter? It could be a limitation set by the battery's BMS.

I'm using 64kwh of lf280k 2 x 2p16s with 2 seperate BMS I will check but I think they're both set higher 

An Axpert? I've just maxed out both MPPT strings on my 10kW Kodak and noticing the same behaviour, will only charge to a max of 100A. Setting the current limit higher doesn't do anything.

If you turn on extra load in the house it'll pull from the panels but won't use this available power to charge.

Can't be BMS limit as they're hooked into Solar Assistant and not the inverter.

It could be early firmware. What is the main (U1) inverter firmware version? 

On 2024/06/18 at 12:21 PM, LiFePOWER said:

An Axpert? I've just maxed out both MPPT strings on my 10kW Kodak and noticing the same behaviour, will only charge to a max of 100A. Setting the current limit higher doesn't do anything.

If you turn on extra load in the house it'll pull from the panels but won't use this available power to charge.

Can't be BMS limit as they're hooked into Solar Assistant and not the inverter.

Mines mppsolar but I believe they're basically the same. But yes mine acts exactly the same.

6 hours ago, Coulomb said:

It could be early firmware. What is the main (U1) inverter firmware version? 

There only 3 months old. But firmware version is 73.07 

On 2024/06/20 at 2:05 AM, Coulomb said:

It could be early firmware. What is the main (U1) inverter firmware version? 

 

I've updated mine to the below and still locked at 100A:

 

Hi

Same issue with Easun - ISolar SMW 11Kw TWIN

CPU: 78.08 Secondary CPU: 38.17 

Do you have connected inverter -BMS communication? ( I saw LiFePOWER use Solar Assistant for the BMS communication. )

My JK BMS communication doesn't work. And maybe this is the key?, if BMS communication works then inverter can reach 150A limit?

I just thinking...

Did you find solution?

Coulomb started to see the issue but not found any obvious reason.

Best regards Robert

On 2025/04/14 at 1:56 PM, robert1968 said:

Coulomb started to look at the issue but did not found any obvious reason.

Someone mentioned derating; it seems that it can derate charging power for four reasons. The reasons were high internal temperature, high PV voltage, low utility voltage, and I forget the fourth one. I was shocked to see a manual extract indicating that if PV voltage is over 360V, the charge current would be derated to a maximum of 90A. I suspect that there would be a ramp based on PV voltage, not a sudden drop of 33% as implied.

That gives me a promising avenue to continue searching, if and when I find the time.

Hi all,

I looked at the code and I can confirm that the de-rating conditions are there and that they are only two-state - on/off, The only little difference from the chart that robert1968 posted on AEVA forum is in temperature derating. It only activates when inside temperature exceeds 45 and heatsink temperature exceeds 65 at the same time. It deactivates when both inside temperature drops below 40 and heatsink temperature below 55.

One solution may be splitting the strings to get around 300-350V and connecting the rest of the panels to another inverter that would serve only as a charger, connected in parallel to the same battery.

Hi Coulomb and Kuba.cz

Many thanks for taking time and investigating the issue!

I'm very happy to hear you found this strange settings in code. I'm amazed by the magic you have. :)

Anyway thank you!

Especially thanks for the solution proposal. However I don't really like it, because I didn't plan to have another inverter and add rearrange cables on roof.

Is it an option to modify the software with disable the voltage limit? Or just simple overwrite it to 500 V?

Is it ethical from a company not even mentioning this conditions and advertising 150A charge current???

I'm very upset about this sales behaviour! I feel that is not correct.

Anyway many thanks again for you 😀

Best regards Robert

10 hours ago, robert1968 said:

Is it an option to modify the software with disable the voltage limit? Or just simple overwrite it to 500 V?

It is possible to modify the software, the problem is that we don't know why the manufacturer put this derating condition there. In theory I can't see which part of the hardware could be the reason for this kind of limitation. But there may be parasitic effects which only become apparent when the inverter is operated above these conditions. I mean, the risk of a catastrophic failure is very high with such software modifications.

Hmm. All your words are true. Thanks.

I'm always meets with 100A limit (never see 90A) so this is because of 420V pv2 voltage and not because of the high internal temperature.

Basefd on what Coulomb said:

> "if PV voltage is over 360V, the charge current would be derated to a maximum of 90A."

If we leave the temp protection then risk is maybe less.

I'm still thinking to take the risk, and try it... At least to see it's works -as Proof of concept.

Can you please make only this modification on my current software version? (CPU: 78.08 Secondary CPU: 38.17 )

14 hours ago, robert1968 said:

Can you please make only this modification on my current software version? (CPU: 78.08 Secondary CPU: 38.17 )

I don't have the 78.08 original file, I could only find 78.07 for Axpert Max E 11 kW Twin '28066. I can patch that one.

Is there any experience on using Axpert's firmware in EASun? Not sure if they are the same.

Many thanks to be open for patching.

Can export Easun firmware somehow?

Or only manufacturers can provide? I contacted them with questions, but no response since two weeks. So I ve doubt they will help.

If we have Easun firmware then can you compare to Axpert one?

I would prefer to take only one risk at once. (Change PV 350V limit to let's say 450V)

Best regards Robert

8 hours ago, robert1968 said:

Can export Easun firmware somehow?

Unfortunately there is no easy way to do that. Manufacturers lock the chips by storing a 128-bit password at a specified address in the flash.

8 hours ago, robert1968 said:

If we have Easun firmware then can you compare to Axpert one?

There are multiple EASun firmwares available directly on Voltronic's server, but not the one for your inverter with the F28066 DSP.

I'm really sorry I said something without checking it.

I assumed this the only option. Apologies.

How can I check I have F28066 DSP?

On 2025/04/18 at 1:01 PM, robert1968 said:

How can I check I have F28066 DSP?

If you are successfully running 78.xx firmware then you have a '28066 DSP.

I'm 99% sure that recent EASuns are genuine Voltronic models, largely if not completely made in the Voltronic factory. Back in 2021, it may have been a different story. Large genuine Voltronic reseller MPPSolar accused EASun and others of being clone makers, and warning prospective buyers not to buy them. That web page is still there, but perhaps no longer easily findable:

https://www.mppsolar.com/v3/fake/

I have a theory that Voltronic actually sues some clone makers, or threatens them with legal action unless they convert to becoming a genuine reseller. That appears to have happened with EASun and possibly a few others.

In any case, I regard all EASun firmwares as genuine now, and as far as I know, they are completely compatible and interchangeable.

So thanks to Coulomb, I got the exact 78.08 firmware and changed the derating threshold from 360V to 450V, patched file attached.

Robert1968, you can test it, if you wish. Good luck!

Note for others who haven't read the topic: We don't know why this kind of derating is there and whether it is necessary. Using this firmware may lead to a catastrophic failure of the inverter. Use at your own risk!

MAXE11K_TWIN_DSP_78.08_derate_at_450V.zip

Many Many thanks to you Kuba.cz making the firmware so fast! I'm really appreciated.

And thanks Coulomb for the very interesting background information. :)

I start to read the firmware update topic. I'm afraid I should buy some interface if I don't have on the shelf.

Edited April 19, 20251 yr by robert1968

Hi Kuba.cz

I found how to run firmware upgrade here: https://forums.aeva.asn.au/viewtopic.php?p=87767#p87767
There are 3 way to do.
I choose option one. i have USB OTG (i hope mine is also OTG, because looks exactly same as it is in the instruction page picture)

Formatted a PEN drive with Fat32 then extracted MAXE11K_TWIN_7808_derate450V.inv file and renamed to mks2.hex then copied to the pen drive root folder.
No other file copied - Is this right?

Now i should go to the inverter put the pen with USB OTG to the Inverter USB and initiate upgrade
Access the USB transfer menu by holding down the display's top left button for 3 seconds. Select Upgrade Firmware by pressing the button next to UPG; confirm by pressing the button next to "YES". The reflash process takes about 10 minutes.

Can you pls confirm this is OK ?

Update: I followed the step until Confirm upgrade - to check there is no error with steps until this.
Now i postponed the upgrade till morning. (i choose 'No')
I don't take any risk in night...

Edited April 19, 20251 yr by robert1968

On 2025/04/15 at 8:17 PM, kuba.cz said:

One solution may be splitting the strings to get around 300-350V and connecting the rest of the panels to another inverter that would serve only as a charger, connected in parallel to the same battery.

Thay a good idea that i have planned to do my one of my installation 🤗 (Axpert Max 8K x2 in parrallel)

Edited April 20, 20251 yr by fhocorp

9 hours ago, robert1968 said:

Formatted a PEN drive with Fat32 then extracted MAXE11K_TWIN_7808_derate450V.inv file and renamed to mks2.hex then copied to the pen drive root folder.
No other file copied - Is this right?

My understanding, without owning a Max model, is that this should work. This is based on me reading the firmware; as far as I know, "mks2.hex" is not mentioned in any Voltronic documentation. So this is pure theory. So far, I'm not aware of anyone saying "hey, this does not work". Please report your results, good or bad.

Neither I have a MAX model to test it. But the .inv file is actually IntelHex, so the .hex extension makes sense. The other files are generated by Arena Reflash Tool automatically. It's the same data in another format.

So, Robert1968, I think your steps are correct.

Hi,
i started Upgrade in the morning. i confirmed the question with yes.
Then screen put a kind of progress bar but after a few seconds it went back to default screen. Seemed nothing happened. no restart no disconnect or interrupt of battery charge.
I expected 10 minutes upgrade as Coulomb wrote but it takes a few seconds....

So i assume maybe it does not run upgrade??

Max battery_charging_current is still 100A

I restarted the inverter but still 100A is the max.

See the inverter status:
root@beelink1:~# mppsolar --getstatus

Command: Q1 - Q1 query

--------------------------------------------------------------------------------

Parameter Value Unit
ac_input_voltage 235.2 V {'icon': 'mdi:lightning'}
ac_input_frequency 50.0 Hz
ac_output_voltage 230.3 V
ac_output_frequency 50.0 Hz
ac_output_apparent_power 529 VA
ac_output_active_power 396 W
ac_output_load 4 %
bus_voltage 445 V
battery_voltage 53.6 V
battery_charging_current 100 A
battery_capacity 64 %
inverter_heat_sink_temperature 59 °C
pv_input_current_for_battery 9.8 A
pv_input_voltage 328.6 V
battery_voltage_from_scc 0.0 V
battery_discharge_current 0 A
is_sbu_priority_version_added 0 bool
is_configuration_changed 0 bool
is_scc_firmware_updated 0 bool
is_load_on 1 bool
is_battery_voltage_to_steady_while_charging 0 bool
is_charging_on 1 bool
is_scc_charging_on 1 bool
is_ac_charging_on 0 bool
rsv1 0 A
rsv2 0 A
pv_input_power 3226 W
is_charging_to_float 0 bool
is_switched_on 1 bool
is_reserved 0 bool
unknown_value_in_response_22 b'030'
unknown_value_in_response_23 b'58.40'
unknown_value_in_response_24 b'000'
time_until_the_end_of_absorb_charging 1 sec
time_until_the_end_of_float_charging 0 sec
scc_flag SCC not communicating?
allowscconflag 00
chargeaveragecurrent 00
scc_pwm_temperature 59 °C {'device-class': 'temperature'}
inverter_temperature 33 °C {'device-class': 'temperature'}
battery_temperature 36 °C {'device-class': 'temperature'}
transformer_temperature 36 °C {'device-class': 'temperature'}
gpio13 2
fan_lock_status Not locked
not_used 000
fan_pwm_speed 100 %
scc_charge_power 3231 W {'icon': 'mdi:solar-power', 'device-class': 'power'}
parallel_warning 0000
sync_frequency 0.0
inverter_charge_status bulk stage {'icon': 'mdi:book-open'}
unknown_value_in_response_18 b'0'
unknown_value_in_response_19 b'060'
unknown_value_in_response_20 b'030'
unknown_value_in_response_21 b'150'
unknown_value_in_response_25 b'120'
unknown_value_in_response_26 b'0'
unknown_value_in_response_27 b'0000'
--------------------------------------------------------------------------------

Should i record the a video from upgrade ? maybe you see is it passed or not.