1C or if it says you can charge that specific battery higher on the lists here
https://www.brca.org/documents/batte...ion-lists.html whatever it says you can charge it at.
I don't know those exact batteries but if they're 5,000mAh 1C is 5A, 2C is 10A, 3C is 15A etc.
Edit to add..... if they're the HV lipos they can still only be charged to the normal max lipo voltage 8.4V (rule copied out beloew)
3.7 LiPo/LiFe batteries may be charged to a maximum of:-
2S Batteries may be charged to a maximum of 8.40v (LiPo) resp. 7.40v (LiFe).
1S Batteries may be charged to a maximum of 4.20v (LiPo) resp. 3.70v (LiFe).
LiPo/LiFe drive batteries must be a ’Lipo sack’ at all times when being charged or discharged. This applies to any discharging procedures except during a race or when using organiser supplied resistors.