float @ 90% SOC

Hello,
My Classic is entering float with the batts not totally charged (90%/95%). Absorb time is set to 2 hours. Should I just add 30 mm more or are there other settings that need to be changed?
thank guys.
My Classic is entering float with the batts not totally charged (90%/95%). Absorb time is set to 2 hours. Should I just add 30 mm more or are there other settings that need to be changed?
thank guys.
Off-grid. Midnight Classic 200. 2,480W array. Magnum Inverter MS4448PAE. 225Ah*8 @48V Trojan T105RE Smart Carbon. MN bkrs box.
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Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
Note that you don' t necessarily have to do this every day. You can set the classic to skip X days. It's important to get the batteries fully charged with a long enough absorb once or twice a week, but you could just bulk and float for a couple of days and have it do a full absorb every third day for example.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
I haven't check the input voltage at the end of absorb. I understand that it should be around 2% of my 225ah batt (~ 5 Amps) so should I set absorb time on that basis? My load during the day is pretty stable.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
They don't know what type or capacity battery you have.
- Assorted other systems, pieces and to many panels in the closet to not do more projects.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
There will be basic setting, AGM, FLA, ...
But think of all the different types of setups, You can have a 4K watt array feeding a lead acid battery! A weekend setup with a huge bank say 1200ah forklift battery, providing just a 5% charge rate, or a 400ah bank in a cloudy region. A finishing rate of 30 amps or 2-3% of a 1200 ah battery is charging rate for a small battery bank. Best to input a finishing rate perhaps more than a timed charging, and perhaps they might consider that at some point, but I think that varies by type as well. I mostly have had FLA.
- Assorted other systems, pieces and to many panels in the closet to not do more projects.
dapago,
Personally, would set the Absorb (called 'Bulk' by Trojan) voltage, as specified in the Data Sheet in the following Link -- 59.28 V, 59.3 should be fine:
http://www.trojanbattery.com/pdf/datasheets/T105RE_TrojanRE_Data_Sheets.pdf
Float is noted as 54.0 V, and EQ V is 64.8 V.
Target SG for full-charge is 1.277.
I, too, use Skip Days -- Skip three, and charge on the fourth day.
BUT. dapago probably needs to find settings that will bring the battery bank to full-charge, before Skipping Days.
Be certain to mount the BTS on one battery in the center of the battery bank.
The Temperature Compensation value is -- 5 mV/Cell/C. Would suggest setting Temp Comp EQ = YES.
As suggested elsewhere, would set the Charge voltages to those recommended by Trojan, and watch the SGs to see how they respond. If still not reaching 1.277 SGs, then try increasing the Absorb time by about 30 minutes, for a start:
http://kb1uas.com/mnsforum/index.php?topic=3560.0
The Classic Ending Amps function works great, when using the WBjr with a 50 mV 500 A Shunt. CC EA (without a WBjr) can work well, especially if there are no heavy loads that are present near the time when Absorb should be ending. Heavy loads that cycle every few minutes should not be an issue when using CC EA, as long as the heavy load is off for about five minutes or so. Used CC EA for about 5 - 6 years without any problems.
All FWIW, Vic
Say for example you had a battery which has no loads and is fully charged at days end, overnight the self discharge is almost negligible, the next day sun up battery is at 99.9% charged, the controller sees the voltage and instead of doing a bulk charge goes immediately into absorbtion, after the time out of absorption, it switches into float.
Next night the battery is discharged to 80% SOC, following morning the controller reads the voltage and goes into bulk until the absorption setpoint is met, absorbtion takes place and times out, then float. This is using a standard algorithm without user input, would this not be a good starting point, to establish a base line from which to adjust setpoints and timed functions to suit particular needs of a system, if needed, wether it be a daily or weekend use, or specific battery requiments. Sometimes too many interventions can lead to problems and these can sneak up undetected and result in premature battery failure.
In the case of @dapago, it would seem his array is a little too large for the battery, 2480W for 225Ah, so if anything the bulk amperage may be on the high side, but once it goes into absorbtion, the current should drop as the level of charge increases. So if it is possible to limit the bulk charge current would this not be the prudent thing to do? The absorption stage would taper the current down to avoid gassing and terminate when the time has expired, then go into float, assuming there are no large loads which may prompt the controller into going back into bulk.
There seems to be different uses for the term bulk/absorbtion as @Vic stated so I copied the information from a Morningstar manual which are the terminologys as I understand them. So as @Estragon mentioned using absorbtion to mix the electrolyte, is this bulk being referred to as absorbtion, as bulk is more likely to do just that.
Second system 1890W 3 × 300W No name brand poly, 3×330 Sunsolar Poly panels, Morningstar TS 60 PWM controller, no name 2000W inverter 400Ah LFP 24V nominal battery with Daly BMS, used for water pumping and day time air conditioning.
5Kw Yanmar clone single cylinder air cooled diesel generator for rare emergency charging and welding.
It might make some sense to limit bulk current, but I don't think it's a big issue unless batteries are hot.
As you and Vic have said, the main thing in this case is to get absorb set to fully charge batteries. OP says he checks sg regularly which should help get there.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
Hi mcgivor,
When you said,
"Say for example you had a battery which has no loads and is fully charged at days end, overnight the self discharge is almost negligible, the next day sun up battery is at 99.9% charged, the controller sees the voltage and instead of doing a bulk charge goes immediately into absorbtion, after the time out of absorption, it switches into float",
The above is the way that most CC behave now. There is generally NO Bulk voltage setting, because with PV charging, there is not enough current available to immediately reach the Absorb voltage, so maximum available charge current eventually allows the battery voltage to rise to the set Absorb voltage, and THEN, the Absorb stage begins.
If the only "load" on the battery was self-discharge, then the Bulk stage will be fairly short, as would be the required Absorb. But with a fixed Absorb time set in the CC, and Ending Amps was not being used, the Absorb, would most likely be much longer than necessary.
The Outback, and the MidNite CCs ALL have three stage charging, PLUS EQ. MorningStar IS a bit different, but they all have those "four stages".
Few other CC manufacturers have battery type settings, except for different NiCd, perhaps. Morningstar is the only manufacturer that I know of that has an L-16 setting. Much of this is a hold-over due to their very limited range of charge parameters, due to the use of DIP SWITCHES.
Later, Vic
I just can not get my mind on that EA function.
What I understood at that point is that EA has priority on absorb time but how and when does EA know to limit the amp going into the batts?
Will EA:
- totally cut the charge and if so until when?
- if set to 1,5% of my batt capacity, limit the charge to 3.5A and if so until when?
That way, you are only reading the battery amps, not the solar-inverter amps
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
- Assorted other systems, pieces and to many panels in the closet to not do more projects.
The second way can work okay and is probably better than nothing, but the wbjr and shunt aren't really expensive and is the better way to do end amps.
Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter