liepo4 temp cut off setting, both charge and discharge

[timmeh]

Hi guys i was trying to find a thread already covering this but no luck so here it goes.

What setting would one input in say my daly bms for high and low temp cut off for charge and discharge?

As far as i know low temp cut off for charge should be 5 deg celsius. and i think high temp charge cut off is 60c

But from memory discharge can be a bit lower than 5c?
Its more charging that damages the battery when at low temps?

 

[snoobler]

Hi guys i was trying to find a thread already covering this but no luck so here it goes.

What setting would one input in say my daly bms for high and low temp cut off for charge and discharge?

In the absence of specific cell data, 3°C for low temp charge cut-off. -10°C for discharge cut off, 40°C for charge high temp cut off.

As far as i know low temp cut off for charge should be 5 deg celsius. and i think high temp charge cut off is 60c

But from memory discharge can be a bit lower than 5c?

Yep. Depends on the cell spec, but -10°C is pretty common.

Its more charging that damages the battery when at low temps?

Violently so. It causes permanent plating of lithium on the terminals thus significantly reducing capacity when charged below freezing.

 

[timmeh]

In the absence of specific cell data, 3°C for low temp charge cut-off. -10°C for discharge cut off, 40°C for charge high temp cut off.



Yep. Depends on the cell spec, but -10°C is pretty common.



Violently so. It causes permanent plating of lithium on the terminals thus significantly reducing capacity when charged below freezing.

O yes sorry i forgot to add my cell. I have 280ah EVE cells.

 

[snoobler]

There are two data sheets for versions of Eve cells in Resources:

Battery Cell Data Sheets

diysolarforum.com

 

[timmeh]

ok so it seems the data sheet says charge 0 to 60c and discharge -30 to 60c

The discharge test shows a test done at 55c and -20c so i guess i will chose the following settings>

Charge low cut off 3c and high 55c means cold mornings it wont charge till it warms up a bit. in australia winter mornings can be 0c but very rarely in the negative, it usually abut 2-3c on most winter mornings.

Discharge low cut off -5 and max 55c means on the same cold morning i can still use my power which will warm the battery a tad and then will start charging a bit later in the morning when ambient temps warm up and discharging the battery has warmed it a little. i don't think iv ever seen -5c on a winter morning so no point setting it lower.

Im setting my max tempts to the 55c a bit below 60c only because some days can reach 45c heat in Australia in some parts while traveling and it gives me 10c headroom for the battery adding its own heat from use.

 

[bigdee]

thanks for sharing the info it helped a lot.