How low can I discharge a EG4 or SOK 48V battery?

[OnGrid]

My question is, can I discharge a 48V server rack 48V battery more than "recommended".

AND IF I DO, will I be able to charge if with solar If I have a Growatt or MPP All-In-One inverter??? I thought a lot of these All-In-Ones won't power on if the battery doesn't have a certain minimum amount of voltage?

I'm looking for the answer to my questions, not what's best for the longevity of the battery.

Thanks

 

[houseofancients]

dont think you can unless you unhook the bms.
may inask why you want to risk your cells ?

 

[Bobert]

Not much point in over discharging a lifepo4 battery their is almost no energy left to be used at the bottom of the charge cycle.

 

[joanna_lannie]

The minimum discharge voltage of a single LiFePO4 battery with reference to 3.2V is between 2V and 2.5V. Maybe the minimum discharge voltage of a 48V battery is between 32V and 40V, which should be the minimum discharge voltage of a 48V battery. Of course, you can go below 32V if you want, but you are killing the battery on purpose, which means your battery is over-discharging.

 

[HighTechLab]

The SOK battery will shut down if you discharge it below the recommended parameters. Some all-in-ones do not need battery power to turn on and start charging, however others do. If yours falls into the category of "needs power", then you would need some other source to get things "jump started".

 

[SignatureSolarJames]

BMS is not going to allow it on EG4, the cells come at around 107ah but they burn into the list ah rating. what is the scenario you are envisioning?

 

[OnGrid]

The SOK battery will shut down if you discharge it below the recommended parameters. Some all-in-ones do not need battery power to turn on and start charging, however others do. If yours falls into the category of "needs power", then you would need some other source to get things "jump started".

Thank you.

That was my question and that was the answer I thought it would be.

So if I purchased IE a Growatt 48V 3000 LTN-ES

The SOK battery will shut down if you discharge it below the recommended parameters. Some all-in-ones do not need battery power to turn on and start charging, however others do. If yours falls into the category of "needs power", then you would need some other source to get things "jump started".

Thanks for answering my question.

So if by chance my battery was to low and I had IE 48V Growatt 3000 LVM-ES (battery less), then I wouldn't need another source to charge it?

 

[SignatureSolarJames]

both of our models have a recovery function if you full drain them

 

[robby]

My question is, can I discharge a 48V server rack 48V battery more than "recommended".

AND IF I DO, will I be able to charge if with solar If I have a Growatt or MPP All-In-One inverter??? I thought a lot of these All-In-Ones won't power on if the battery doesn't have a certain minimum amount of voltage?

I'm looking for the answer to my questions, not what's best for the longevity of the battery.

Thanks

This is a 12V LFP battery Curve but a 48V one would have the same Curve.
As you can see even if you did try your plan and went past 5% SOC the remaining time to get to 40V and start to do real damage would only get you at best an extra 1-5 Minutes depending on the Load. Is it really worth it? Also I suspect your Inverter might cut out with a low voltage warning before you got there.

 

[Bobby Cannon]

My growatt inverter low limit before using grid is set to 30%. I'm wondering if I could drop that to 20% and not negatively affect my batteries.

 

[Supervstech]

My growatt inverter low limit before using grid is set to 30%. I'm wondering if I could drop that to 20% and not negatively affect my batteries.

It depends on how the limit is measured. If it uses coulumb meter to chart actual usage, possibly.
If it uses a voltage chart, unlikely. As draining rate affects voltage… 30-20% isn’t much. And the voltage chart doesn’t take into effect load drop…

 

[Bobby Cannon]

It depends on how the limit is measured. If it uses coulumb meter to chart actual usage, possibly.
If it uses a voltage chart, unlikely. As draining rate affects voltage… 30-20% isn’t much. And the voltage chart doesn’t take into effect load drop…

I think it uses the BMS communication from the battery. Meaning the battery is saying it has 30% charge remaining. I think dropping this to 20% will not negatively affect the battery.

My batteries are hitting 30% a bit early which means the inverter goes into "charge from utility until 80% (setting)". I want to prevent this. If I could get another 1 to 2 hours, then the inverter could just use solar only to charge.

 

[HighTechLab]

both of our models have a recovery function if you full drain them

Hi James, how do you use this recovery feature, it's the first time I've heard of this.