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How to limit charged and discharged (voltage) on li-ion battery bank?

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Navig8tor

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So, in order to prolong battery life (in cycles) it is advised to cycle li-ion far from the upper an lower voltage limits, so I want to limit the "charged state" voltage of each cell to 4,0V and the "discharged state" to 3,0V.
The problem is I can't find a BMS that works with those voltage numbers.
Can anyone point me a solution to implement those voltage limits?
 
Navig8tor said:
So, in order to prolong battery life (in cycles) it is advised to cycle li-ion far from the upper an lower voltage limits, so I want to limit the "charged state" voltage of each cell to 4,0V and the "discharged state" to 3,0V.
The problem is I can't find a BMS that works with those voltage numbers.
Can anyone point me a solution to implement those voltage limits?
Click to expand...
The Chargery BMS has lots of adjustment including the numbers posted. Worth a look.
 
grizzzman said:
The Chargery BMS has lots of adjustment including the numbers posted. Worth a look.
Click to expand...

I've looked for the chargery bms's and they all seems to be disigned for Lipo, LiFe and LiTo, not for Li-ion...
Do you know of a specific model for Li-ion?
 
Do not use the BMS to control cycling bandwidth thresholds. Simply set the absorption on your solar charge controller to the highest SOC you wish to achieve. And set the LVD on your inveter to control the lowest SOC you wish to achieve.

The BMS LVD and HVD should only be used if there is a failure in the inverter or solar charge controller. If you use the BMS to turn off your inverter, and the caps empty over time and you cause inrush current without resistor, and repeat this process, you will cause damage to the FET's of the BMS. And possibly damage the caps.

The BMS safety features should be seen as an emergency disconnect. Not one to manage your systems cycling bandwidth.
 
Will Prowse said:
Do not use the BMS to control cycling bandwidth thresholds. Simply set the absorption on your solar charge controller to the highest SOC you wish to achieve. And set the LVD on your inveter to control the lowest SOC you wish to achieve.

The BMS LVD and HVD should only be used if there is a failure in the inverter or solar charge controller. If you use the BMS to turn off your inverter, and the caps empty over time and you cause inrush current without resistor, and repeat this process, you will cause damage to the FET's of the BMS. And possibly damage the caps.

The BMS safety features should be seen as an emergency disconnect. Not one to manage your systems cycling bandwidth.
Click to expand...

Thanks Will.

Is it ok to use a solar charge controller to charge a battery with a dc power supply (instead of input from solar panels)?
And is it possible to manage (limit) discharge voltage with a DC to DC converter?
 
What if the BMS only balances when the cells are full (4.2V) and the CC is set to max out at 4.0V?

Assuming a good, stable battery environment for home solar (with CC and inverter) = I still don't see the need for the BMS outside of cell balancing. My batteries never get close to freezing or really hot.

While I am it, seems like one could make their own cell balancing array quite easily.
 
The BMS protects the individual cells from going under and/or over voltage. Just monitoring battery bank total voltage does not do that. Under and over voltage will kill Li cells.
You can order from China and wait or try to get some customer service. I like having someone on this side of the ocean to test and assure me the product is first quality and not seconds. Someone to answer the phone and help me along. But each their own.
 
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