Thundersky LFP activation charge why ?

[evtdriver]

email sent.

 

[evtdriver]

Answer from Thundersky :

For single cell, the highest charging voltage is 4.2V. For battery pack, it is better to charge to 3.8-4.0V to avoid overcharge. By the way, the lowest discharging voltage is 2.5V for single cells, while for battery pack, 2.8V is better.

For the first use, it it better to charge the battery full, because the battery is only charged 60% capacity before shipment and it would lose more capacity when shipment. It would be easily overdishcarged, if you don't charge it first before use.

When charging, 0.1C is ok, the only issue that it would be slow to charge the cells full. Normally, we would charge the battery by 0.3-0.5C.

So there is no activation issue, they just ask to charge before to use.
I don't understand why Thundersky lifepo4 need to be charged so high.

 

[AndyH]

So there is no activation issue, they just ask to charge before to use.
I don't understand why Thundersky lifepo4 need to be charged so high.

Good work!

It's not that they have to be charge so high, it's that they CAN be and still deliver a 3000+ cycle life. TS did mention that 3.8V is better, and their docs show a longer life with more conservative voltages/SOC.

Compare the TS 4.3V-4.2V range with the Shandong Hipower 3.8V, other companies' 3.65V with these numbers from A123-Systems:

View attachment A123_limits.jpg

Andy