diy solar

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Awful Top Balance or BMS Issues

like i said, not sure about you inverter, but you would like you absorbtion to start at 3.40 per cell ( for a 16s battery that would be 54.4v ) and last about 2 hours
eq. should be disabled all together
max voltage should be 54.4 too
 
I saw those too in my search.
How desperate are you to get that last .5% of your battery capacity?

I think my recommendations in post #18 were pretty good...
Yep I agree.

I think I was just hunting for that magic absorption setting which is a misunderstanding from me.

I’m not bothered about the extra 5% let alone .5.

I’ll charge to 55.5v and go from there. Reckon I’m best setting that via the over voltage protection on inverter or BMS?
 
Yep I agree.

I think I was just hunting for that magic absorption setting which is a misunderstanding from me.

I’m not bothered about the extra 5% let alone .5.

I’ll charge to 55.5v and go from there. Reckon I’m best setting that via the over voltage protection on inverter or BMS?
you bms will tell you inverter when to shutoff charging through the comms..
set it in the bms.

monometer is the bms stands for single
 
I’ll charge to 55.5v and go from there. Reckon I’m best setting that via the over voltage protection on inverter or BMS?
No, your BMS is your battery safety device. It should be set to the battery chemistry limits or just inside to be conservative: LiFePO4 limits: 2.5Vpc-3.65Vpc. I set my BMS to 2.8Vpc - 3.62Vpc protection.

Your charge controller is used to control yer charging.
Looking at your settings pic:
Is your battery really 50Ah at 48V?
Where is the max charge voltage (55.5V) set? (should be "bulk" or similar)
 
No, your BMS is your battery safety device. It should be set to the battery chemistry limits or just inside to be conservative: LiFePO4 limits: 2.5Vpc-3.65Vpc. I set my BMS to 2.8Vpc - 3.62Vpc protection.

Your charge controller is used to control yer charging.
Looking at your settings pic:
Is your battery really 50Ah at 48V?
Where is the max charge voltage set? (should be "bulk" or similar)
this is a communicating system @MisterSandals .
therefor the bms will tell the inverter to stop charging.
in 99% of the cases , a communicating bms will trump any setting in the inverter.
because it is telling the inverter to stop charging there's also no abrupt shutoff causing overloads anywhere
 
I was worried you'd say that! Cells were grade B but from a reputable supplier here in the UK so I'm kind of ruling those out atm.

Looking at the logs from the BMS, the inverter seemed to keep at constant 75A until the BMS threw a high voltage warning, when a cell hit 3.5, 97.5% soc & 55.5v. At that point, the max cell was 3.5, min was 3.44.

Inverter is connected via CAN to Seplos BMS & it can see SOC & Battery Voltage.
HI Tim9321, I know tis is an old thread.....I've recently upgraded my installation from 14s100p18650 packs which I've had in place for 4 years, I'm now a proud owner of the Seplos vertical rack with the Seplos BMS200A and 16 EVE280ah Grade A cells. I also have a Solis Hybrid inverter RHI-5K-48ES 4G, I'm interested to learn if you have issues with the BMS and Solis inverter, I managed to charge my Pack to 100% but I did get the Alarm of Overvoltage from the BMS to the Solis which obviously disconnected, it then reconnected once the voltage dropped backdown once the BMS was happy, it was noticeable that one Cell was out by 220mv at 100% SOC but once stopped charging all cells were within 2mv. I would like to know if your using the Pylon battery settings on the Solis as I was advised to do your using a custom battery setting and if so what those setting are. Thanks in advance
 
HI Tim9321, I know tis is an old thread.....I've recently upgraded my installation from 14s100p18650 packs which I've had in place for 4 years, I'm now a proud owner of the Seplos vertical rack with the Seplos BMS200A and 16 EVE280ah Grade A cells. I also have a Solis Hybrid inverter RHI-5K-48ES 4G, I'm interested to learn if you have issues with the BMS and Solis inverter, I managed to charge my Pack to 100% but I did get the Alarm of Overvoltage from the BMS to the Solis which obviously disconnected, it then reconnected once the voltage dropped backdown once the BMS was happy, it was noticeable that one Cell was out by 220mv at 100% SOC but once stopped charging all cells were within 2mv. I would like to know if your using the Pylon battery settings on the Solis as I was advised to do your using a custom battery setting and if so what those setting are. Thanks in advance
The disconnect is by design..

You should have done a top balance of your cells before putting them in the seplos case ( see resource section here for a how-to), as most server rack batteries have a passive 200ma balancer, which will take a whole lot of cycles to balance out your cells ( if ever).

There are multiple path forward from here :
1 buy a desktop power supply and after the BMS disconnects your inverter, disconnect the power cables to the inverter and do a per cell charge of the lowest cells untill they are balanced

2 get a good size resistor ( old style 12v lightbulb can be used) and discharge the highest cells ( not going under 3.37v ) untill the pack is balanced

3. Get a programmable active balancer ( neey 4a is good ) and set start voltage to 3.45, stop voltage at 3.37.
This may take some time, but no energy is lost and you can attach it to the case, leaving it in, and do it's work while you simply use your battery
 
The disconnect is by design..

You should have done a top balance of your cells before putting them in the seplos case ( see resource section here for a how-to), as most server rack batteries have a passive 200ma balancer, which will take a whole lot of cycles to balance out your cells ( if ever).

There are multiple path forward from here :
1 buy a desktop power supply and after the BMS disconnects your inverter, disconnect the power cables to the inverter and do a per cell charge of the lowest cells untill they are balanced

2 get a good size resistor ( old style 12v lightbulb can be used) and discharge the highest cells ( not going under 3.37v ) untill the pack is balanced

3. Get a programmable active balancer ( neey 4a is good ) and set start voltage to 3.45, stop voltage at 3.37.
This may take some time, but no energy is lost and you can attach it to the case, leaving it in, and do it's work while you simply use your battery
Thanks for your reply, as the cells were within 2mv I didn't think I would need to balance them in fact last night I was at 1 mv after a full charge. What I'm really after is to cross reference/confirm with someone what the Solis should be set to with the batteries and this BMS. I could post what I currently have under custom battery, if that helps.
 
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