voltx basic 100aH charge voltage vs bms protection voltage

[rgormley]

I have 2 of the "aldi" voltx 100aH lithium batts

the manual states for the voltx basic
"for optimum performance , you must charge to 14.6v"
"over protection is 14.4v"

so how can i charge to 14.6v if the over voltage protection on the BMS is set to 14.4 volts?

also i presume i should only charge to 13.8v (3.45v x 4 cells) ??

yes i `m a newbie with lithium's

this was from a downloaded user manual

can you explain this or would this be a typo?

Thanks!

 

[DIYrich]

14.6v is for "max" performance, not necessarily "optimal". Ignore it. 13.8v is good.

 

[Steve_S]

ll equipment MUST BE Voltage Corrected & Calibrated (VERY IMPORTANT)
Divide Values by 2 for 12V. Multiply by 2 for 48V.
Bulk/Absorb: 27.6V Absorb for 45 minutes (3.45vpc) (some call this boost) *never actually runs the full 45mins because of EndAmps
Equalize: OFF
Float 27.5V (3.437vpc)
MIn Volts: 21.2V (2.650vpc)
Max Volts: 28.6V (3.575vpc)
Rebulk Voltage: 25.6V (3.200vpc)
End Amps/TailCurrent: (*1) (** Allows for full Saturation at set Float Voltage)
(*1): End Amps is calculated : (100AH X 0.05 = 5A or 280AH X 0.05 = 14A)
Coulumbic Efficiency / Battery Status Meter Efficiency for LFP = 99%.
This gets the bank charged to full with high amps (Constant Current -= Constant Voltage) and then FLOAT (Constant Voltage - Variable Current) tops off so the cells are at 3.47Vpc.

!*!*! Do Not forget to adjust for Voltage Offsets between the Actual Voltage @ Battery Terminal & at the Solar Controller.
Also make sure the Inverter Low Volt Cutoff is also corrected/adjusted.

 

[Reed Cole]

It says right there that 14.4 is what they recommend you set your charge controller to. 14.6 is the overcharge protection that the BMS has.

 

[Steve_S]

It says right there that 14.4 is what they recommend you set your charge controller to. 14.6 is the overcharge protection that the BMS has.

14.4V = 3.600 VPC . That is NOT Acceptable. LFP is LFP and far too many companies state a higher daily charge profile than is appropriate. When you charge vells above 3.475-3.500 they are BEYOND the Working Voltage range and one or more will often "RUN" and trigger a High Volt
Disconnect. Battery Disconnection by Inverter for "LOW VOLT" should also NEVER be below 2.700V / 10.8V to prevent the BMS from bricking itself, allowing it to take charge when applied.

The BMS IS THE GUARDIAN and is in charge of protecting against High / Low Voltage or Overdraw conditions, that does not mean that you should be triggering those safeties, best to never do so !

 

[Reed Cole]

14.4V = 3.600 VPC . That is NOT Acceptable. LFP is LFP and far too many companies state a higher daily charge profile than is appropriate. When you charge vells above 3.475-3.500 they are BEYOND the Working Voltage range and one or more will often "RUN" and trigger a High Volt
Disconnect. Battery Disconnection by Inverter for "LOW VOLT" should also NEVER be below 2.700V / 10.8V to prevent the BMS from bricking itself, allowing it to take charge when applied.

The BMS IS THE GUARDIAN and is in charge of protecting against High / Low Voltage or Overdraw conditions, that does not mean that you should be triggering those safeties, best to never do so !

Ok, just pointing out what the user manual says that the OP was confused about.

 

[rgormley]

At what voltage will the BMS do balancing on any out of balance cells(if any) in the battery? will 3.5v /cell (14v) let the BMS balance the cells?

i did an experiment, i charged a 12v 100ah (voltx basic) at 5amps CC to 14v CV (using a power supply) the battery i presume was at mostly at 100 SOC as the next day as the current draw was only 112mA.
would be great to see the charge curve overnight and the "knee" but i don't have the equipment to measure, visualize yet....

So would this 112mA be just the BMS now doing it`s balancing?

 

[pollenface]

I believe so

 

[Steve_S]

I just reviewed the VoltX site and the products listed. Those BMS' are not SmartBMS' they have no balancing capabilities.. quite basic. Only their High Capacity ESS batteries have SmartBMS and the extra features & functions. The few milliamps used is just BMS function if everything else is off/disconnected.

 

[rgormley]

oh "Those BMS' are not SmartBMS"
so what functions do they provide? high/low voltage disconnects and over current?
Do you the link to this information, i would like to read it in full.

Cheers,
Richard

just spotted this on the voltx site "The BMU is also equipped with equalisation modules"

• BMU​

  BMU is the most basic management unit of the system, integrated within the cell and the lithium battery module. It is mainly responsible for collecting the voltage, temperature and other data of each cell. The BMU is also equipped with equalisation modules which improve the consistency of the system for smooth operation. Aside from this, it also features a temperature control system that automatically switches on a fan during high temperature conditions to effectively dissipate the heat.

 

[rgormley]

Here is the response from Voltx when i queried the voltage settings
hhmm i thought that 15V is way to high for a lithium battery on the upper level of protection.

this is the Email response

Hello Richard,
So sorry for the delayed response.
As per our tech team the Overcharge protection should be at 15V
Our team will re-check the manual so we can check the typo error in the manual.
Please wait for our update.
Regards,