Patrick sv
New Member
Yeah true. I am quiet happy how she performs now with Lead Acid settings. I leave it
USING LEAD ACID SETTINGS ON LIFEPO4
- Thread starter Patrick sv
- Start date
HughF
New Member
Why is your inverter set to 58.4v when you need to charge to 55.2?
Inverter settings should be 55.2, absorption timer of 30 mins or so (for now), float of 53.8 (that’s what I’ve used for 6 yrs, works well at letting the cells rest whilst the sun carries the loads)
Inverter settings should be 55.2, absorption timer of 30 mins or so (for now), float of 53.8 (that’s what I’ve used for 6 yrs, works well at letting the cells rest whilst the sun carries the loads)
Patrick sv
New Member
Patrick sv
New Member
Can i try it on User Defined?
Patrick sv
New Member
HughF
New Member
Ok, I get it now. User defined won’t work without incoming can messages, and lead acid isn’t user-adjustable…
Sounds like a shit inverter ?
You need to get your absorption setpoint changed, one way or another.
Sounds like a shit inverter ?
You need to get your absorption setpoint changed, one way or another.
Patrick sv
New Member
Yes its Solis Hybrid. Absorption set to what voltages?
HughF
New Member
55.2 - always 55.2 for lfp, none of this 58.4/3.65 rubbish…
Patrick sv
New Member
You are saying that Lead Acid not user adjustable?
You are saying that Lead Acid on Solis not adjustable? Looks like i can adjust absorption/charging voltages
HughF
New Member
You told us somewhere up there ^^^ that the only one that was user adjustable was the ‘user defined’ charging profile.
I’m not in front of your inverter, you are. I’ve told you the voltages to use, crack on and have a go at adjusting them.
I’m not in front of your inverter, you are. I’ve told you the voltages to use, crack on and have a go at adjusting them.
Patrick sv
New Member
Lead acid work well in last 2 days. Yes i have changed absorption to 55.2V so will see overnight what charging Voltages will be.
Tell me Hugh, does anybody push lifepo4 to 100% soc...because 55.2 adsorption will give 3.45v per cell.. is part of the problem here that Patrick wants 100% soc...
Didn’t turn out as a link... YouTube channel Off Grid Garage...
Patrick sv
New Member
I want at least 90% SOC
I have just read through the whole thread again twice, trying to unravel the problem. The facts as far as I can deduce are:-
1) Despite the first sentence from the OP saying "My lifepo4 battery BMS faulty and give incorrect SOC", we do not really know if the BMS is faulty or not.
2) The BMS is reporting 100% SOC when battery voltage reaches 53.1V (and at that point the Solis will, correctly, stop charging).
3) The BMS has twice reported a 53% SOC when the battery "went flat" (whatever 'went flat' means).
4) The OP has reconfigured his Solis to use the lead-acid profile (so as to not respond to SOC info from the battery).
5) Using the lead-acid profile, the BMS will stop charging when 55V is reached.
6) The OP claims all cells are at "identical voltage" even at 'the upper voltage limits of LiFePO4' ! (really?)
7) The Battery / BMS is an unheard of brand from China and there is no data about the BMS, or how to connect to and configure it.
8) The OP believes that both the battery pack and the inverter are female. (really?)
IMHO...
a) the Solis (or indeed any modern hybrid inverter) requires a comms feedback loop to work correctly. As a minimum, the inverter needs this to know at what rate to charge the battery and to know what the battery's SOC is. Using a lead-acid profile should not be considered a long-term solution.
b) the battery needs to have a working BMS to protect the cells and to communicate the correct information to the inverter
c) ideally the user should be able to configure the BMS's parameters or, as a minimum, at least see what those parameters are.
So, as this system has been working and is now not working as expected, obviously something has changed. My first thought was that cells have gone out of balance badly. That would explain the cut off at lower overall voltage. But that does not fit the OP's claim that all the cells are at the same voltage as each other.
I discount the fact that the Solis software upgrade as changed the behaviour that is being reported. For sure an upgrade may stop things working but will not cause the BMS to report incorrect SOC data. That flow of information is from battery to Solis; the Solis will just react to the data received from the battery.
If I were in the OP's position and had the skills I have, I would replace the BMS with a known good brand and use that with the existing LiFePO4 cells.
If the OP does not have those skills, then I would discard the battery completely and make a note for the future of the well-known saying 'buy cheap, buy twice'.
1) Despite the first sentence from the OP saying "My lifepo4 battery BMS faulty and give incorrect SOC", we do not really know if the BMS is faulty or not.
2) The BMS is reporting 100% SOC when battery voltage reaches 53.1V (and at that point the Solis will, correctly, stop charging).
3) The BMS has twice reported a 53% SOC when the battery "went flat" (whatever 'went flat' means).
4) The OP has reconfigured his Solis to use the lead-acid profile (so as to not respond to SOC info from the battery).
5) Using the lead-acid profile, the BMS will stop charging when 55V is reached.
6) The OP claims all cells are at "identical voltage" even at 'the upper voltage limits of LiFePO4' ! (really?)
7) The Battery / BMS is an unheard of brand from China and there is no data about the BMS, or how to connect to and configure it.
8) The OP believes that both the battery pack and the inverter are female. (really?)
IMHO...
a) the Solis (or indeed any modern hybrid inverter) requires a comms feedback loop to work correctly. As a minimum, the inverter needs this to know at what rate to charge the battery and to know what the battery's SOC is. Using a lead-acid profile should not be considered a long-term solution.
b) the battery needs to have a working BMS to protect the cells and to communicate the correct information to the inverter
c) ideally the user should be able to configure the BMS's parameters or, as a minimum, at least see what those parameters are.
So, as this system has been working and is now not working as expected, obviously something has changed. My first thought was that cells have gone out of balance badly. That would explain the cut off at lower overall voltage. But that does not fit the OP's claim that all the cells are at the same voltage as each other.
I discount the fact that the Solis software upgrade as changed the behaviour that is being reported. For sure an upgrade may stop things working but will not cause the BMS to report incorrect SOC data. That flow of information is from battery to Solis; the Solis will just react to the data received from the battery.
If I were in the OP's position and had the skills I have, I would replace the BMS with a known good brand and use that with the existing LiFePO4 cells.
If the OP does not have those skills, then I would discard the battery completely and make a note for the future of the well-known saying 'buy cheap, buy twice'.
Patrick sv
New Member
Flat means that battery was discharged to 0% SOC FROM 53% SOC stated on Solis in seconds. So the working gap between 100% SOC and 53% SOC give me around only 5 kwh usable. Regarding Lifepo4 battery voltages vs SOC my battery charged only to 80% SOC and BMS shut down charging. So my real SOC is always 20% less than its should be.
HughF
New Member
Your pack is full when all your cells are in bypass, not when the shunt says it’s full…
Your battery is empty when the first cell hits low voltage cutoff.
Your battery is empty when the first cell hits low voltage cutoff.
HughF
New Member
People try, but unless your cells are perfect (easier to do now that we have access to such good quality prismatics), you’ll be forever fighting runners, at least in my experience.
Hardly worth going for that last 10 % and stressing about everything shooting up the upper knee, much easier to just go for 3.45 and have done
