Merged LiFeYPO4 1000Ah Winston prismatic cells and all electric galley...

[s/v Jedi]

I guess every battery is different, but these are my observations for the Winston 400Ah cells I have:

Absorption voltage is set at 27.6V or 3.45V per cell. Absorption time is set at either 30 minutes or 1 hour... which are the minimum settings available in my equipment. I know this does not fully charge the cells but it is only a couple percent off, which is fine for me. During charge it becomes obvious the bulk of that happens at 27.0V so just under 3.4V per cell, so at 3.45V it’s clearly climbing up in that upper knee.

Float voltage is set at 27.0V or 3.375V per cell. This means the cell is discharged 1-3% before the controller/charger starts taking over the load.

I top balanced the cells at 3.60V and plan to do so every year. In the mean time I just monitor the cells as I stay far away to anything a BMS or balancer can do.

[newhaul]

Originally Posted by s/v Jedi

I guess every battery is different, but these are my observations for the Winston 400Ah cells I have:

Absorption voltage is set at 27.6V or 3.45V per cell. Absorption time is set at either 30 minutes or 1 hour... which are the minimum settings available in my equipment. I know this does not fully charge the cells but it is only a couple percent off, which is fine for me. During charge it becomes obvious the bulk of that happens at 27.0V so just under 3.4V per cell, so at 3.45V it’s clearly climbing up in that upper knee.

Float voltage is set at 27.0V or 3.375V per cell. This means the cell is discharged 1-3% before the controller/charger starts taking over the load.

I top balanced the cells at 3.60V and plan to do so every year. In the mean time I just monitor the cells as I stay far away to anything a BMS or balancer can do.

Sounds about like my solar controller settings . 13.8v for the bank . My shore charger is set to 14.0v but I'm almost never on shore power .

[CatNewBee]

Whatever makes you feel good.

My settings for solar are 14.6V /1h absorption, 13.5V float.
As I hit 1..2 times per month either, it is no big deal, and the cells are happy balanced and fully charged once in a while.
(3.65V full balanced / 3.375V float).

As you see in the picture, absorption is a rare event and the maximum cell voltage varies over the days with the SOC achieved. It is absolutely healthy to charge a cell from time to time full and to check / allow to balance the cells.

[T1 Terry]

I guess some people have a cell balance system that can move more than the charging current from the high cell to the low cell, otherwise the high cell would go well over 3.6v and into the cell damage zone.
Any and all lithium chemistry cells will be close in cell voltage balance below 100% SOC and above 0% SOC, they all have virtually flat voltage curves inside these two points.
The first thing to understand is that 0% SOC is not zero cell voltage but rather where the cell has discharged all its advertised capacity. To get 110% on a discharge test means the cell was discharged to a minimum voltage, not to 0% SOC. That's fine for a capacity test, but the end of discharge voltage is measured under load, not rested. The discharge for quality lithium batteries is C2, discharged from 100% to 0% in 2 hrs, and load less than that for the discharge test is only fooling yourself, no one else.
If you do monitor the cell voltages and record them when doing the discharge and recharge test you will clearly see why the 3.6v upper limit is the end of the safe zone for regular recharging. I certainly do not suggest to recharge until all cells are at 3.6v every time, that will also damage a battery, but to reset the 100% SOC as needs to be done every so often, all the cells must have a rested voltage above 3.5v, so that requires charging to 3.6v and stopping to watch the cell voltage settle. If it settles below 3.4v then the cell wasn't fully charged and the charging needs to resume until that 3.5v rested is achieved, then and only then will the true 100% SOC be achieved.

As an answer to the question of Apples with Apples, I use Winston cells to build single batteries to the voltage required and capacity required. I've been doing it for over 10 yrs, I spent around AUD $10,000 on cells doing all the hands on research to separate fact from B/S and I gotta tell ya, there wasn't much fact found on the interweb. The number of armchair experts that can't tell the difference between the lithium chemistries and can't be assed actually reading the manufacturers instructions and understanding what they are reading is astounding.
The 4v per cell or even 3.8v per cell without understanding how this figure relates to the actual charging regime is what has caused the most problems and resulted in the most mis-information flooding the web.
Does anyone actually know what other conditions go along with the charging to 3.8v per cell?

If anyone is interested in seeing a video, rather dated now but still a lot of interesting info about LFP cells,

https://www.youtube.com/watch?v=QlDd3jkcxoQ

where Pro Jay Whitacre talks about these cells, how they work

T1 Terry

[newhaul]

Originally Posted by T1 Terry

I guess some people have a cell balance system that can move more than the charging current from the high cell to the low cell, otherwise the high cell would go well over 3.6v and into the cell damage zone.
Any and all lithium chemistry cells will be close in cell voltage balance below 100% SOC and above 0% SOC, they all have virtually flat voltage curves inside these two points.
The first thing to understand is that 0% SOC is not zero cell voltage but rather where the cell has discharged all its advertised capacity. To get 110% on a discharge test means the cell was discharged to a minimum voltage, not to 0% SOC. That's fine for a capacity test, but the end of discharge voltage is measured under load, not rested. The discharge for quality lithium batteries is C2, discharged from 100% to 0% in 2 hrs, and load less than that for the discharge test is only fooling yourself, no one else.
If you do monitor the cell voltages and record them when doing the discharge and recharge test you will clearly see why the 3.6v upper limit is the end of the safe zone for regular recharging. I certainly do not suggest to recharge until all cells are at 3.6v every time, that will also damage a battery, but to reset the 100% SOC as needs to be done every so often, all the cells must have a rested voltage above 3.5v, so that requires charging to 3.6v and stopping to watch the cell voltage settle. If it settles below 3.4v then the cell wasn't fully charged and the charging needs to resume until that 3.5v rested is achieved, then and only then will the true 100% SOC be achieved.

As an answer to the question of Apples with Apples, I use Winston cells to build single batteries to the voltage required and capacity required. I've been doing it for over 10 yrs, I spent around AUD $10,000 on cells doing all the hands on research to separate fact from B/S and I gotta tell ya, there wasn't much fact found on the interweb. The number of armchair experts that can't tell the difference between the lithium chemistries and can't be assed actually reading the manufacturers instructions and understanding what they are reading is astounding.
The 4v per cell or even 3.8v per cell without understanding how this figure relates to the actual charging regime is what has caused the most problems and resulted in the most mis-information flooding the web.
Does anyone actually know what other conditions go along with the charging to 3.8v per cell?

If anyone is interested in seeing a video, rather dated now but still a lot of interesting info about LFP cells,

where Pro Jay Whitacre talks about these cells, how they work

T1 Terry

Quite a bit of info in that video has been proven over time to be not quite correct .
Perhaps you ought to do the reading . Here is near the entire lifetime of lfp in one 10 year and still running strong thread .

https://www.cruisersforum.com/forums...nks-65069.html

Lots of good info .
Learn or burn .

[T1 Terry]

Originally Posted by newhaul

Quite a bit of info in that video has been proven over time to be not quite correct .
Perhaps you ought to do the reading . Here is near the entire lifetime of lfp in one 10 year and still running strong thread .

https://www.cruisersforum.com/forums...nks-65069.html

Lots of good info .
Learn or burn .

:lol: Fancy anyone thinking they know more than the bloke who built lithium batteries for the Mars missions. The rovers were still running after 10 yrs in a rather hostile environment, so I'm backing that he knows a bit about the subject. This is the same Jay Whitacre that established Aquion Batteries and Bill Gates and many other well know identities poured big $$ into the development, I doubt that would happen if he didn't really know his shitte .....

It's been over 10 yrs that I have been building off grid battery systems myself .... but not one system, a lot of systems. We have a few that are now over the 10 yrs since installed and we have some with cells over 13 yrs old, one of my systems is in my Mazda motor home, so I get to see first hand just how they are travelling. They all deliver over the advertised capacity using the factories 0.5CA load testing without a cell dropping below 2.8v, so maybe I do know what I'm talking about rather than becoming an armchair expert by reading what other arm chair experts dribble about on the interweb.
Genuine cycles in systems on the road 24/7 give the true information and that is the part that matters to me, not what you think you know from what you read some where ....... Learn or Burn indeed

T1 Terry

[newhaul]

Originally Posted by T1 Terry

:lol: Fancy anyone thinking they know more than the bloke who built lithium batteries for the Mars missions. The rovers were still running after 10 yrs in a rather hostile environment, so I'm backing that he knows a bit about the subject. This is the same Jay Whitacre that established Aquion Batteries and Bill Gates and many other well know identities poured big $$ into the development, I doubt that would happen if he didn't really know his shitte .....

It's been over 10 yrs that I have been building off grid battery systems myself .... but not one system, a lot of systems. We have a few that are now over the 10 yrs since installed and we have some with cells over 13 yrs old, one of my systems is in my Mazda motor home, so I get to see first hand just how they are travelling. They all deliver over the advertised capacity using the factories 0.5CA load testing without a cell dropping below 2.8v, so maybe I do know what I'm talking about rather than becoming an armchair expert by reading what other arm chair experts dribble about on the interweb.
Genuine cycles in systems on the road 24/7 give the true information and that is the part that matters to me, not what you think you know from what you read some where ....... Learn or Burn indeed

T1 Terry

Great armchair posting there .

Your googlefoo is pretty good

[T1 Terry]

Try a Google search for T1 Terry and T1 Lithium, but then again, don't bother, can't help those that know it all to start with eh

[lmxr]

Originally Posted by newhaul

Quite a bit of info in that video has been proven over time to be not quite correct .
[...]

Do you mind sharing which bits of info you consider to have been proven as not quite correct?

[newhaul]

Originally Posted by lmxr

Do you mind sharing which bits of info you consider to have been proven as not quite correct?

We hashed that out a long while back on the thread I linked to somewhere in the 500+ pages . Don't recall all of it but was about 3 or 4 years ago.

https://www.cruisersforum.com/forums...nks-65069.html
And other threads on here as well .

[BetterDays 2020]

Hello CNB, I have two questions with regards to the REC ABMS system you purchased. I believe I read somewhere that you did not purchase the Victron version of the ABMS. Is this correct? And if so why not as I believe you purchased mostly Victron parts? Also I believe if we now purchase the new REC Bluetooth dongle we don’t need to purchase the software to make the changes we require based on your layout. Can you confirm this? Thanks again.

[CatNewBee]

Originally Posted by BetterDays 2020

Hello CNB, I have two questions with regards to the REC ABMS system you purchased. I believe I read somewhere that you did not purchase the Victron version of the ABMS. Is this correct? And if so why not as I believe you purchased mostly Victron parts? Also I believe if we now purchase the new REC Bluetooth dongle we don’t need to purchase the software to make the changes we require based on your layout. Can you confirm this? Thanks again.

Hi, I purchased my system before REC has done the Victron CAN integration, at this time there was only an announcement, that they are working on it, and only generic CAN support. The hardware is the same (I have the CAN connector too on my harness) , it is just a different firmware so, you can change it if you want at any time.

There was no BT dongle nor WiFi. BT cannot programm the REC, while the WLAN Interface can program it and can flash new firmware as I heard, but I have neither of both at hand, so cannot confirm it. I have the wired serial touch display instead, quite handy btw. and the USB/RS485 programming interface with software package.

I do have Victron integration by 2-wire BMS macro of the Quattro and the optocouplers on the REC to my proprietary settings, I have requested and received a custom firmware at no additional costs, where I can use the relays and the optocouplers independently and have a different sampling rate because of undesirable interferences with my Quattro.

I consider my setup a much more reliable and fail-safe configuration than a CAN BUS integration with an intermediate computer (Cerbo, Venus, CCGX, OCTO), that translates and communicates to some (Victron), but not all devices, also my stand-by power draw in storage mode is significantly lower without such a unit that needs to run all the time.

So even as I can switch to a Victron CAN version at any time by a firmware upgrade, I would not do that. I prefer to have a more independent and granular control to my charge sources and keep the BMS only for balancing and protection. A distributed intelligent logic is more resilient to failures than a centralised approach.

[newhaul]

Question I am considering one of those little one burner induction plates but do I have enough to support it ? 250ah lfp 400 watts solar and wind and a 50 amp b2b charger. 2500 watt trace inverter charger and the backup 3400 watt yanmar diesel generator. ( hopefully never need it ) .
Can I do it ?

[CatNewBee]

Originally Posted by newhaul

Question I am considering one of those little one burner induction plates but do I have enough to support it ? 250ah lfp 400 watts solar and wind and a 50 amp b2b charger. 2500 watt trace inverter charger and the backup 3400 watt yanmar diesel generator. ( hopefully never need it ) .
Can I do it ?

Should work, one burner is 1200...1600W peak?
So will draw between about 60A (50% power)..120A (full power with power boost) 250Ah will give you very likely 3-4h of cooking, if you don't use it for other loads.
The Inverter is a pure sine-wave inverter?

400Wp solar delivers an average of 1600Wh per day, so about 120Ah for recharging (1..2h of cooking)

[newhaul]

Originally Posted by CatNewBee

Should work, one burner is 1200...1600W peak?
So will draw between about 60A (50% power)..120A (full power with power boost) 250Ah will give you very likely 3-4h of cooking, if you don't use it for other loads.
The Inverter is a pure sine-wave inverter?

400Wp solar delivers an average of 1600Wh per day, so about 120Ah for recharging (1..2h of cooking)

The nuwave I was looking at has varied wattage 600, 900, 1300 watt .
Thanks for the quick response