Does a battery management system control charge/discharge?

[PaulLad]

Since the state of charge/depth of discharge is a big factor in longevity, does a battery management system control this, for example, by stopping charging at a specified state of charge and also, cutting of discharge at a soc?

With my solar generator it appears that there is no automated control for this so you have to manually monitor (babysit) and stop the charging/discharging process. Thanks! Is there a workaround for this? Seems crazy to lose 80% or more of the battery life because you can't be there to manually shut down charging/discharging.

 

[upnorthandpersonal]

A BMS will stop charge/discharge based on the state of individual cells. For example, assuming LiFePO4 cells, the BMS can disconnect the battery if one of the cells goes below e.g. 2.5V or goes above e.g. 3.6V. Which device do you have? State of charge is less important than cell voltage.

Edit: no need to create duplicate threads in different topics.

 

[PaulLad]

I have the Bluetti EB2400. According to Will's video

, SOC is very important for longevity. After posting this I thought this would be better for the general forum but couldn't see how to delete it.

 

[upnorthandpersonal]

Yes, and in another video (interview with BattleBorn iirc) they state just charge to 100%. We're literally talking about the difference between 3000 and 4000 cycles. If you would cycle every day, that's 8 years versus 10 years - cycling every single day from empty to full. Your inverter that comes with your solar generator, or the MPPT controller will break before that. Never mind just general calendar aging on the cells.

 

[PaulLad]

Yes, and in another video (interview with BattleBorn iirc) they state just charge to 100%. We're literally talking about the difference between 3000 and 4000 cycles. If you would cycle every day, that's 8 years versus 10 years - cycling every single day from empty to full. Your inverter that comes with your solar generator, or the MPPT controller will break before that. Never mind just general calendar aging on the cells.

Very interesting vid. My batt has NMC chemistry so its sounds like a 90-10 charge profile is going to improve longevity.

 

[upnorthandpersonal]

Is it an off the shelf solar generator you use? If it would be DIY, you could use a Coulomb counter, or even voltage with NMC to determine state of charge. If it's an off the shelf unit, there's not much you can do except keep an eye on it manually. Maybe you could use a timer as well, but it's not going to be accurate.

 

[PaulLad]

Like I said Bluetti EB2400.

 

[upnorthandpersonal]

Like I said Bluetti EB2400.

Oops, missed that, sorry.
Don't think there is much you can do except manually checking it.

 

[Bvillebob]

In the case of Battleborn, it seems to be widely known that they're actually 120 ah batteries, limited to 100 ah charge/discharge by the BMS, so by charging to "100 per cent" you're really only charging to 90 percent.