Can you control a kodak og 10 cut off voltage with a pi that are connected between the battery and inverter the reson that I ask is because the inverter can only be set to 48v and for my battery it needs to be on 49v 

@Coulomb

On 2023/12/16 at 5:06 PM, Dirkie said:

Can you control a kodak OG 10 cut off voltage with a pi...

Without fully patched firmware (there is none and likely never will be for the Max models), you can't properly change the range of the cut-off voltage. The reason is bound up with the way that they compress data for sending between paralleled machines over CAN bus messages that have a limit of 8 bytes of data.

I suppose that a 10 kW model is less likely to need paralleling, so a dodgy patch might be possible. But it would be a fair bit of work.

As far as I know, only settings 12 and 13 (back to utility and back to battery voltage) settings operate with SoC instead of voltage if a BMS is connected.

[ Edit: It seems that cut-off voltage can also be set as an SoC percentage, see Steve87's post below. ] 

The DSP does monitor commands from the BMS saying that the battery should stop discharging, but I don't know if it actually acts on them.

I think that with a lithium battery, you often have to rely on the battery's BMS to shut down the battery when a cell goes low. I don't know how brutal that is on the inverter, battery, or sensitive loads.

Sorry, I don't know much at all about monitoring software like Solar Assistant that operates in a Pi. It might be able to encourage the inverter to drop its loads somehow if the BMS signals that the battery must stop discharging, assuming that the inverter doesn't heed them when connected directly to the BMS (no pi in the middle).

Sorry I can't be more help; battery BMS interactions are still a fairly new area for me.

Edited December 17, 20232 yr by Coulomb

3 hours ago, Coulomb said:

Without fully patched firmware (there is none and likely never will be for the Max models), you can't properly change the range of the cut-off voltage. The reason is bound up with the way that they compress data for sending between paralleled machines over CAN bus messages that have a limit of 8 bytes of data.

I suppose that a 10 kW model is less likely to need paralleling, so a dodgy patch might be possible. But it would be a fair bit of work.

As far as I know, only settings 12 and 13 (back to utility and back to battery voltage) settings operate with SoC instead of voltage if a BMS is connected.

The DSP does monitor commands from the BMS saying that the battery should stop discharging, but I don't know if it actually acts on them.

I think that with a lithium battery, you often have to rely on the battery's BMS to shut down the battery when a cell goes low. I don't know how brutal that is on the inverter, battery, or sensitive loads.

Sorry, I don't know much at all about monitoring software like Solar Assistant that operates in a Pi. It might be able to encourage the inverter to drop its loads somehow if the BMS signals that the battery must stop discharging, assuming that the inverter doesn't heed them when connected directly to the BMS (no pi in the middle).

Sorry I can't be more help; battery BMS interactions are still a fairly new area for me.

Hi thanks for the reply do you maybe know what is the difference between the two firmware for the 10kw inverters 

the one is 56.09. And the author one is 82.06

7 hours ago, Dirkie said:

do you maybe know what is the difference between the two firmware for the 10kw inverters 

the one is 56.09. And the author one is 82.06

As per my What Axpert Firmware is That? post, the first is for the older '2809 DSP chipset, and the latter is for the newer '28066 DSP chipset. One may have a few more minor revisions, as indicated by the difference in minor version numbers (after the dot). 

Hi @Dirkiethat is possible. Most ppl use Solar assistant. This screenshot below if of an OG10 in action & as you can see, this has the the newer firmware, that incorporates % SoC from the Battery BMS. If however, you don't have Comms supported by either your battery or your inverter & you use the USE settings this then goes to Voltage settings for inverter shutdown value. Solar assistant is a Pi based platform & a very useful tool to carry out the function you have just enquired on. 

 

8 minutes ago, Steve87 said:

Hi @Dirkiethat is possible. Most ppl use Solar assistant. This screenshot below if of an OG10 in action & as you can see, this has the the newer firmware, that incorporates % SoC from the Battery BMS. If however, you don't have Comms supported by either your battery or your inverter & you use the USE settings this then goes to Voltage settings for inverter shutdown value. Solar assistant is a Pi based platform & a very useful tool to carry out the function you have just enquired on. 

 

Yes the batteries are set to use 

One step further is that the Solar Assistant and Pi support a large list of batteries in terms of rs485/Rs232 & CANbus protocols & that was the inventors original business study: To support a huge variety of batteries to non supported inverters & bridge the Comms Gap. By using Solar assistant you will have SoC % from your battery extracted by the Pi & be able to run your OG10 as if it had Comms. The Pi will be your SoC % Interpreter between your Inverter & battery.

On a off grid settup where there are only solar input and no grid input at night the battery will go down until cut off voltage then the inverters will shutdown until the solar power put the inverters back on then it wil charge the battery. So until what % will it charge the battery before it wil put on the power and can that % also be set somewhere 

2 minutes ago, Steve87 said:

One step further is that the Solar Assistant and Pi support a large list of batteries in terms of rs485/Rs232 & CANbus protocols & that was the inventors original business study: To support a huge variety of batteries to non supported inverters & bridge the Comms Gap. By using Solar assistant you will have SoC % from your battery extracted by the Pi & be able to run your OG10 as if it had Comms. The Pi will be your SoC % Interpreter between your Inverter & battery.

I have n solar assistant pi thet I am going to try 

@Coulomb do you know on what percentage must the batteries be for the inverter to switch on power in an off grid system 

On 2023/12/18 at 10:44 AM, Dirkie said:

do you know on what percentage must the batteries be for the inverter to switch on power in an off grid system

That's actually a really hard question to answer; I thought it would be fairly easy.

So far it looks like it will use voltage thresholds for battery under-voltage if the battery type is non-lithium (including USE). Under-voltage means it's under the cut-off voltage setting.

But if the battery type is a lithium type (PYL, WEC, SOL...), then so far it looks like it never considers the battery to be under voltage. I suspect strongly that I haven't found alternative code that kicks in for lithium battery types.

Hopefully I'll sort it out soon.