Honda EU26i Manuel De L'utilisateur page 41

DC Application
The DC receptacle may be used for charging 12 volt automotive-type
batteries only.
DC output will vary according to the position of the EcoThrottle switch.
When the EcoThrottle switch is turned to the Eco position and the AC
output is not used, the DC current will be about one-third of the rated
current.
DC Current
Eco throttle switch
Model
EU26i
EU30is
1.Connect the charging cable to the DC receptacle of the generator and
then to the battery terminals.
DC CIRCUIT PROTECTOR
38
OFF
10 A
12 A
(Example: EU26i)
ON OFF
(do not use the AC output)
approximately 3.3 A
approximately 4 A
Eco
CHARGING CABLE
(SOLD SEPARATELY)