@ james butcher

I found this info on the Efest 10440 at Illumn.

According to the info printed there, as well as what was posted above by fran82; you should be good to go charging your 10440’s at up to .5A without undue danger.
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Efest IMR10440 V1 350 mAh High Discharge Flat Top
SKU:2201
Availability: In Stock

$3.00
PRODUCT DETAILS
Efest IMR10440 V1 350 mAh High Discharge Flat Top

* Please Note: Do NOT charge these cells above 0.5A, this will reduce the life of the battery. For longevity, charge current should be below 0.5A

Specifications:
Typical Capacity: 350 mAh
Nominal Voltage: 3.7V
Discharge End Voltage: 3.0V
Max Recommended Charging Current: 0.5A
Charging Voltage: 4.20+–0.05V
Max. Continuous Discharging Current: 3A
Internal Resistance: N/A
Dimensions:
43.18mm (L) x 10.16 mm (D)
Weight: 10g