Use a 12 V⎓ battery with a capacity of 4 or 7 A∙h. The maximum battery size for installation in the hub body is 151 × 65 × 94 mm, and the weight is 5 kg. For batteries of this form factor, special mounts are provided in the hub body.
You can use batteries of a different capacity if they are suitable in size and the charging time does not exceed 30 hours. The maximum charging current for the Hub Hybrid battery is 500 mA.