good day

I believe that a inverter sends the electrical charge to the battery

now the built -in BMS of the battery itself controls the flow of electricity coming into it as well what is going out

the BMS knows its full of charge so if the electricty comes by it will just say NO to taking more charges

so even if different batteries are connected form different manufacturers the build in BMS still controls the flow

i dont see how any of the batteries can get damaged

the inverter just sends signals and the BMS just says its full

i have been wqatching closely at my inverter

if there is a need to charge batteries it pulls power from the solar panels

if no need the solar panels are at rest also

and the batteries rest if nothing is being used

still my point is i dont see a issue with connecting different brands because of the BMS controlling everything in the battery

it will take a charge until its full

so if i have 2 different batteries for example one charges full,,BMS keeps it full and the inverter will keep sending a charge to second battery until that ones BMS says its full

so this has nothing to do with the inverter

however some systems are designed with batteries and inverters to fit one another ...same brand etc.....to communicate that way

some systems are made as a unit..i see why those can not be mixed around

then other brands are free to go connect to batteries to any inverter without issues

some BMS states that they can handle so many situations of different currents flowing for protection..the BMS protects the battery

but most people say its not a good thing

and another solar place i spoke to agrees with me

so is there a issue after all?

Edited July 2, 20251 yr by Dennis

Not quite. The INVERTER controls the charging. The BMS tells the inverter what it wants, and the inverter does what the BMS tells it.

The only direct action the BMS has is a failsafe option to disconnect the battery if the inverter tries to do something outside of what the battery can handle.

51 minutes ago, JustinSchoeman said:

Not quite. The INVERTER controls the charging. The BMS tells the inverter what it wants, and the inverter does what the BMS tells it.

The only direct action the BMS has is a failsafe option to disconnect the battery if the inverter tries to do something outside of what the battery can handle.

yes so correct..i can agree...this is inline with what im saying

20 hours ago, JustinSchoeman said:

The INVERTER controls the charging. The only direct action the BMS has is a fail safe option to disconnect the battery

That's the way it is. The inverters are programmed to manage the battery charging on the base of battery voltage, provided the determining parameters are set to battery specifications. I have seen weird BMS SoC readings that give me goose bums when thinking that the inverters should depend on them. I prefer not to have BMS to inverter comms.

Read my thread "Are BMS reliable?".

21 hours ago, Dennis said:

yes so correct..i can agree...this is inline with what im saying

The OP mentions different batteries. If one BMS understands french(protocol) the other battery Afrikaans in what language will the inverter talk to the batteries? Further dip switches need to be set between batteries. How will they understand each other.

This being the reason if comms is used and not voltage for controlling charge that it does become important to have batteries that talk the same protocol.

This could be why @JustinSchoeman mentioned not quite. This is my understanding.

interesting

so every battaery even different manufacturers all have BMS built in these days

so the BMS protects the battery

the invereter just sends electrical charges

so it spossible then to have different manufacturers on the same pararalel connection..not series

18 minutes ago, Dennis said:

interesting

so every battaery even different manufacturers all have BMS built in these days

so the BMS protects the battery

the invereter just sends electrical charges

so it spossible then to have different manufacturers on the same pararalel connection..not series

If you can get different batteries to balance cells around the fully charge voltage, it could work. I wouldn't want to have batteries run into over voltage, so I would let the one with the lowest fully charged voltage talk to the inverter.

if one inverter handles a lot of batteries at the same time..usally or logically there would be voltage drop..so there is zero damage ..no over voltage..no heat..again no damage

under current allways is no heat= no damage

over voltage allways leads to damage in the long run

but we have a middle man called BMS that stops all over voltage and regulates it to the batteries

so no damage

Edited July 3, 20251 yr by Dennis

8 hours ago, Scorp007 said:

This being the reason if comms is used and not voltage for controlling charge that it does become important to have batteries that talk the same protocol.

I don't quite understand your logic. Voltage is the same in every language and the only information that does not lie. That's the reason why all inverters are programmed to manage charging on the base of battery voltage.

3 hours ago, Dennis said:

but we have a middle man called BMS that stops all over voltage and regulates it to the batteries

No, that's not the way it works. The BMS cannot regulate anything, it can only cut off the battery in case certain limits are exceeded. If the parameters are set correctly in the inverter there will never be over-voltage as long as there is no failure.

7 hours ago, Beat said:

I don't quite understand your logic. Voltage is the same in every language and the only information that does not lie. That's the reason why all inverters are programmed to manage charging on the base of battery voltage.

No, that's not the way it works. The BMS cannot regulate anything, it can only cut off the battery in case certain limits are exceeded. If the parameters are set correctly in the inverter there will never be over-voltage as long as there is no failure.

i agree correct parameters makes a difference..but BMS will allow or not the charges that come in

15 hours ago, Beat said:

I don't quite understand your logic. Voltage is the same in every language and the only information that does not lie. That's the reason why all inverters are programmed to manage charging on the base of battery voltage.

No, that's not the way it works. The BMS cannot regulate anything, it can only cut off the battery in case certain limits are exceeded. If the parameters are set correctly in the inverter there will never be over-voltage as long as there is no failure.

I might be wrong but when using comms then the instruction is send as per the protocol. That's why there are DIP switches to be set between batteries.

When using voltage like you do then there is no problem understanding it.

Just look at the automotive industry where prior to 2006 each manufacturer used their own protocol. Only after that some standard protocol was devised and from then most analyzers could read the ECU unit.

@Dennis Just look at the topics and see how many Pylontech batteries have been over charged due to the BMS not stopping the overcharge. Not worth the risk if the BMS does not do as you mentioned which we belief will always happen.

@Beat Yes the voltage does not lie but the BMS that tells the inverter what to do can as per these picture where batteries in parallel at the same voltage gets a 26% difference in SOC. We must just be aware of this. Sorry that the top picture cut off the 6 at the average cell voltage of 3.316V.

Edited July 4, 20251 yr by Scorp007

36 minutes ago, Scorp007 said:

Just look at the topics and see how many Pylontech batteries have been over charged due to the BMS not stopping the overcharge. Not worth the risk if the BMS does not do as you mentioned which we belief will always happen.

Not just Pylontech. When I had Revovs I was told that my batteries had been overcharged. When I queried this I was shown a log entry. There were various interesting things about this log entry, but the one that is relevant here is that the BMS had not stopped the overcharge.

this is very strange that the BMS didnt work or failed or was not programmed correctly

i hope not all manufacturers have this issue

seems most use the same BMS in batteries across the board

i have read of the different names of BMS being used by manufacturers

they mostly share the same common thing

but then you do get some that produce and make their own ones for certain combined setups

Edited July 4, 20251 yr by Dennis

so tell me which is a way to get a battery "read" if there is no comms port on it

it has a BMS but how to get info from it if there is no port on it?

any one know

is their a inverter that does it

or is their a 3rd part dongle or need to open that battery and plug wires into it from the inside

im asking i dont know how would one get info for a battery without a port or screen on it

Dennis, are you a bot or something?
Just curious that you spew out single disjointed lines of text with little or no proper use of grammar or writing style.

Just Curious this side...

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