Hi, everyone
after 50 years of installing, selling and designing off grid systems, I drank the lithium Kool-aid and switched over.
After having a four hour fight with the Hawk's bay and Roise, I got them to play together. Here is what I have the six, Eco-Worthy 100Ah server rack batteries set for in the Hawk's bay
I have my Midnite solar Hawk's bay configured as follows:
Chemistry: Lithium
Capacity: 600 Ah
Absorb: 56.0 V
Absorb time: 6 minutes
Float: 53.6 V
Rebulk: 48.0 V
EQ time: 0
Ah efficiency: 98%
Temperature compensation: 0
EQ temperature compensation: 0
WBJr: enabled
Ending amp 0
now, I'm sitting on 6kWp of solar, and on a sunny day, I wake up and see the batteries are sitting there at 87%. By 10-11AM, they are charged to 97%. And here is the kicker, the Hawk's bay goes to float and there is NO, nada, zero, zip current coming out.
Hawk's bay reports 'resting'
Now I know that if a quart is holding a quart, it's doing the best it can. I can't push more energy into the batteries if they are already full.
And the batteries report 'idle' with no current going into or out of them.
But, and here's the kicker, Roise is on line and producing power at around 300W. How can that be? If the batteries are in idle, and Hawk's bay reports 0 current, Rosie isn't pulling juice out of thin air. I see, via WHZbang jr, that Rosie is drawing 6-8 A.
If the batteries are supplying current, then it must be coming from the hawk's bay, but yet there is no sign of current flow.
I need some help
mike
When the batteries are full and it goes to float, the SOC on the batteries SOC on my system usually drops to 98 or 99% before the Hawkes Bay will supply power in float. So the power is coming out of the batteries.
Is that what you are seeing ?
Regarding the setpoints you have, I can't speak to what the bms is programmed for . But on my JKbms I have the top point set to 3.45v per cell and also the balance point. And the SOC is going to reset to 100% around those setpoints too.
At 3.45v the cells are 99% full . The JKbms has 2 amp active balancer.
So no idea what your bms setpoints are.
I guess you are using closed loop and letting the bms dicate the charging ?
I use open loop and have the absorb time set to 30 minutes . It takes time to balance the cells , especially if your bms does not have active balancing and has passive shunt resistors of around 100 to 200 ma .
I used to use 53.6v float but upped it closer to 54v because when the inverter kicks on to bigger load it doesn't drag voltage down below 53.6v and start taking power from the batteries when there is lots of power available from pv in the day.
I had to adjust my rebulk up but dont' remember right now what that is.
On my system I can monitor each cell in every battery and see what is going on in graphs and balances and all that.
I spent a lot of time watching past Off Grid Garage on youtube and his testing lifepo4 cells using various charging and discharging setpoints, he graphed and explained it all, and what he says makes sense so that is where I informed my charging setpoint decisions.
Of course since I have different charge controllers,and passive pace bms and the jkbms active balancing, I had to tweak things till they all were playing nicely together.
But in reality - most of the power in lithium is on the flat part of the curve so any cell imbalances are only noticeable at the very top and bottom of the charge/discharge and battery pack capacity won't even suffer that much if balance perfection is not there.
I know there are lots of different lithium charge philosophies . Some have to do with longevity of the cells, some have to do with battery manufacturers wanting their customers not be be calling them about cell balancing being a bit off or the bms not reporting 100% .
Anyway - have fun with the new lithium - they certainly do charge faster because of the amount of power that can go into them compared to lead acid. That comes in very handy on the short over cast days of winter when the sun might just poke out for brief periods in a day or week.
I have not had to run my generator in over a year - benefit of over sizing pv and enough kwh of battery storage.
Larry
thanks, Larry,
I have six of the 100Ah eco-worthy server rack batteries.
They are in open loop.
I just set the absorb time to 30 minutes. Here's what I changed:
Absorb: 56.0 V
Absorb time: 30 min
Ending Amps: 12 A
Haven't touch anything else.
it's descerning to see 0 power from the Hawk's bay when it's a nice bright day. But if the batteries are full, there's no place to put the energy.
BTW.... I can't seem to get the SOC to read any thing other than 'CAL' on the MNSPG (?) display.
mike
I use these with 100% operation:
ABSORB = 56.2V
FLOAT = 54.2V
ENDAMPS = 1A
REBULK = 53.5V
ABSORB TIME = 30M
See, the 6 batteries will draw current in ABSORB doing top-balance, the batteries will turn off their CHARGE RELAY sometimes called "CMOS" (don't know why, they are solid-state relays) and when the last one is off the ENDAMPS drop to "ZERO", this triggers the Hbay to go to FLOAT after 90 seconds.
I have been running this way for years with my V1 EG4's Lithiums.
Quote from: qrper on September 28, 2026, 11:22:57 AMthanks, Larry,
I have six of the 100Ah eco-worthy server rack batteries.
They are in open loop.
I just set the absorb time to 30 minutes. Here's what I changed:
Absorb: 56.0 V
Absorb time: 30 min
Ending Amps: 12 A
Haven't touch anything else.
it's descerning to see 0 power from the Hawk's bay when it's a nice bright day. But if the batteries are full, there's no place to put the energy.
BTW.... I can't seem to get the SOC to read any thing other than 'CAL' on the MNSPG (?) display.
mike
Did you set up the Whizbang in the menu's ? There is a place in the Hawkes Bay menu where you have to select it. I am not in front of my HB now so don't remember what it is called.
Larry
Quote from: ClassicCrazy on September 28, 2026, 12:46:41 PMQuote from: qrper on September 28, 2026, 11:22:57 AMthanks, Larry,
I have six of the 100Ah eco-worthy server rack batteries.
They are in open loop.
I just set the absorb time to 30 minutes. Here's what I changed:
Absorb: 56.0 V
Absorb time: 30 min
Ending Amps: 12 A
Haven't touch anything else.
it's descerning to see 0 power from the Hawk's bay when it's a nice bright day. But if the batteries are full, there's no place to put the energy.
BTW.... I can't seem to get the SOC to read any thing other than 'CAL' on the MNSPG (?) display.
mike
Did you set up the Whizbang in the menu's ? There is a place in the Hawkes Bay menu where you have to select it. I am not in front of my HB now so don't remember what it is called.
Larry
sure did. set both the HB and rosie. It's under ext sensors
I know you have a understanding of how systems work. But I have a couple ideas.
1) Are all of the inputs and outputs on one side of wizbang? And only the batteries' negative on the other side.
2) Is it possible that because your load is small, and assumed equally shared by each of the 6 batteries. That none of your batteries are registering the usage. (Battery bms's are known to be very inaccurate at minimal amps.)
3) Are you using the "surface charge" of the battery and the top few percent of the battery capacity? With the float valve set below 54v. You may have to draw 20-30ah (?) out before your system reaches your float voltage. What is the system voltage when the anomaly is happening? Between 56v - 53.6v ?
My brother's system will draw off his batteries for awhile before his system actually reaches float voltage. I believe his float valve is closer to 54.1v .
Bump your Float up to 55 to 55.5V that will get the MPPTs making some power to power the loads. 53.6 is to low you will deplete the battery back some before they wake up
Quote from: FNG on September 29, 2026, 12:42:21 PMBump your Float up to 55 to 55.5V that will get the MPPTs making some power to power the loads. 53.6 is to low you will deplete the battery back some before they wake up
I set float to 55.5 and that really kicked things in gear. I'm seeing 60A going into the battery, which is setting at 53.9 right now. My absorb voltage is 56.0, so I hope to hit that this afternoon, and the float at 55.5 the rest of the day. Rosie is pulling some current, but there's not much running right now.
the batteries report 97% charged.
And some time this morning, both rosie and HB are now showing SOC%. Is it correct? Don't know
mike
Quote from: qrper on September 28, 2026, 09:35:09 AMIf the batteries are supplying current, then it must be coming from the hawk's bay, but yet there is no sign of current flow.
I need some help
mike
What'll happen is once the absorb timer is done it will drop down to float voltage. During that time loads will power from the batteries until battery voltage drops to float, then the hawkes bay will start delivering power again to maintain float voltage.